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Aquaculture and urban marine structures facilitate native and non-indigenous species transfer through generation and accumulation of marine debris
Abstract
Both the invasion of non-indigenous marine species (NIMS) and the generation and accumulation of anthropogenic marine debris (AMD) are pervasive problems in coastal urban ecosystems. The biosecurity risks associated with AMD rafting NIMS have been described, but the role of aquaculture derived AMD has not yet been investigated as a biosecurity vector and pathway. This preliminary study targeted 27 beaches along the
Coromandel Peninsula, New Zealand, collecting debris from belt transects. Plastic (specifically plastic rope) was the dominant AMD present on beaches. The most common biofouling taxa were hydroids, bryozoans, algae and polychaetes, with one NIMS pest species, Sabella spallanzanii, detected fouling plastic rope. Our findings demonstrate that aquaculture is an AMD (plastic rope) generating activity that creates biosecurity risk by enhancing the spread of NIMS. The rafting of S. spallanzanii on AMD generated at aquaculture facilities is currently an unmanaged pathway within New Zealand that needs attention.
... Herbert et al., 2012;Van der Schatte Olivier et al., 2018;Gentry et al., 2019). Although it is generally believed that unfed bivalve aquaculture has a smaller impact on the environment compared to other types of aquaculture, the rapid expansion of bivalve aquaculture has raised concerns about its potential negative environmental impact (Campbell et al., 2017;Rech et al., 2018;Leibowitz et al., 2019). There are many reports on the impacts of bivalve farming on the environment, but the information is less organized. ...
... Non-indigenous farmed bivalve species may also escape from aquaculture farms through detached, abandoned, or otherwise discarded gear (DADG) (Castilla et al., 2005;Astudillo et al., 2009;Calder et al., 2014;Holmes et al., 2015;Campbell et al., 2017;Rech et al., 2018). For example, between 2001 and 2005, 34 detached buoys originated from the aquaculture facilities in the Bay System of Coquimbo, Chile were found floating between 1 and 45 km away from the northern-central coast of Chile (Castilla et al., 2005;Astudillo et al., 2009). ...
... The results showed that at least six bivalve species (Pinctada imbricate, Isognomon bicolor, Aequipecten heliacus, Euvola ziczac, Pododesmus rudis and Chama congregata) and one gastropod (Cerithium litteratum) entered the coasts of the British and Ireland by rafting macro-litters from the Caribbean and southeast coast of the USA. Campbell et al. (2017) surveyed 27 beaches along the Coromandel Peninsula, New Zealand for DADG. The study found that plastic ropes were the most common DADG, and non-indigenous marine species Sabella spallanzanii have been discovered. ...
... Previous NZ studies measured marine debris on beaches in the Coromandel Peninsula on the North Island (NI) (Campbell et al., 2017), from the coasts of the Canterbury region on the South Island (SI) (Clunies-Ross et al., 2016), and around Auckland (NI; Bridson et al., 2020). Earlier beach surveys were decades old (Gregory, 1978), and all studies were localized. ...
... From this random starting point, the coastline was followed to the right (when facing the water), until the following criteria were met for a site: 1) East-facing (when facing the water, compass direction was either NE, E, or SE) 2) Length was > 1 km 3) Faced open ocean 4) Away from (> 500 m) obstructions (such as headlands, breakwaters, jetties) 5) Accessible from the land through public roads These site criteria were applied to reduce potential confounding factors such as fluctuations in oceanic and climatic influences or localized effects (e.g. urban marine structures; Campbell et al., (2017). Furthermore, a large part of the SI's west coast is inaccessible from land. ...
... This study showed a similar mean AMD density to a prior NZ study on 27 beaches in one region (Waikato, NI), however, measurements were made on sample sites with a different aspect, smaller size, and on a different part of the beach (Campbell et al., 2017). Other NZ debris studies have reported results in different units and measured fewer beaches, making comparisons challenging (Gregory, 1999;Hayward, 1984Hayward, , 1999. ...
Terrestrial sources of marine debris on beaches are substantial, increasing, and are primarily a result of mismanaged waste on land. The scale, source, and composition of beached marine debris in New Zealand was determined by surveying 41 beaches, with triplicate belt transects, across the North and South Islands. Results demonstrated a significant spatial variance, with the South Island showing a significantly higher mean density than the more populated North Island by count as well as by weight. The majority of all anthropogenic marine debris detected was plastic and arrived through the water. Explanations for regional variances in debris presence are difficult to ascertain with certainty but could not be explained by population density and proximity. These findings contribute to the understudied field of marine debris research in New Zealand and the Southern Hemisphere and provide a starting point for evidence-based mitigation. Recommended changes to future monitoring programs are made. This first national baseline study of marine debris in New Zealand serves as a reference for follow-up studies, including research at other locations.
... Rates of exotic species introductions in different oceans have been increasing over the last three decades, probably reflecting the greater intensity of anthropogenic activities such as shipping and aquaculture (Carlton, 1989;Ruiz et al., 2000;Neves & Rocha, 2008). The use of sheltered harbors worldwide has increased connectivity among biogeographical regions (Clarke et al., 2004;Lopes, 2009;Castro et al., 2017) and greatly contributes to colonisation by several non-native species. ...
... Recent studies have indicated other possible routes of non-native species introductions. For example, Campbell et al. (2017) reported that floats and plastic ropes used in aquaculture installations can serve as artificial substrates for encrusting organisms, including serpulid polychaetes. Among the water-borne anthropogenic materials that have drawn attention in recent years, plastic is known to act as a vector for non-native species dispersal (Ruiz et al., 1997;Bumbeer & Rocha, 2016;Campbell et al., 2017). ...
... For example, Campbell et al. (2017) reported that floats and plastic ropes used in aquaculture installations can serve as artificial substrates for encrusting organisms, including serpulid polychaetes. Among the water-borne anthropogenic materials that have drawn attention in recent years, plastic is known to act as a vector for non-native species dispersal (Ruiz et al., 1997;Bumbeer & Rocha, 2016;Campbell et al., 2017). Zibrowius (1970) pioneered the study of the Serpulidae in Brazil. ...
Abstract Species of Serpulidae are common on benthic and biofouling communities, occurring attached on both natural and artificial substrates. In this paper, Serpulids were collected from intertidal to subtidal areas, on rocky shore and suspended artificial plates in port areas. Herein we report three new records of serpulid species to the coast of Rio de Janeiro, Brazil. We also discuss the misidentification of Spirobranchus tetraceros, which was previously reported to the north of Rio de Janeiro.
... A preliminary study along the Coromandel Peninsula indicated marine debris from aquaculture and urban marine structures act as rafts for non-indigenous species, creating biosecurity risks by enhancing their spread and dispersal (Campbell et al., 2017). Several biofouling taxa were documented, with the most common being hydroids, bryozoans, algae and polychaetes. ...
... Boren et al., 2006;Godoy & Stockin, 2018;Hidalgo-Ruz et al., 2021) • biosecurity risks by helping non-indigenous species move to new locations (e.g. Campbell et al., 2017) • health hazards, potentially causing personal injury (e.g. Campbell et al., 2019). ...
This report provides the first insights into plastic pollution in Te Taitokerau (Northland). It summarises available empirical data on macroplastics and microplastics in ecosystems and organisms, as well as the sources of plastic and the pathways it travels.
We hope that by quantifying plastic pollution across the region, this report will help to: a) address knowledge gaps, b) inform policy development, c) better develop scale-appropriate solutions, and d) raise awareness and inspire change to reduce and mitigate plastics in the environment. This report can be used as a tool and a baseline for ongoing environmental monitoring and reporting.
... The fouling organisms inhabiting the plasticlusters and the weather conditions preceding their detection suggest that the structure was formed by the accumulation of floating plastic debris over a period of weeks (see Fig. 6). Fibers and expanded polystyrene spheres (Styro-foam®) are among the most common meso-and microplastic items in the littoral areas of Tunisia (Abidli et al., 2018), and the clustering of floating debris is a common phenomenon inside ports and marinas, where debris is relatively abundant and can be accumulated by wind and currents (Campbell et al., 2017;Masiá et al., 2021;Sempere-Valverde et al., 2023). Plastics can be clustered by surface tension, entanglement, biological growth and binding substances, and these processes are likely to have taken place in the formation of the structures reported in this study. ...
... Plasticlusters represent a novel habitat formed by the aggregation of marine debris inside marinas. They could provide relatively complex structures that might serve as microhabitats for sessile and motile NIS and vectors for their dispersion, as they have the risk of disaggregate into floating plastic items and spread (Campbell et al., 2017;Ibabe et al., 2020;Fernandez et al., 2022). However, this is the first study on plasticlusters and, given the low replication in this initial study, it will be important to continue describing, characterizing, cataloguing and monitoring plasticlusters in harbor areas. ...
Plastic debris is a significant and rapidly developing ecological issue in coastal marine ecosystems, especially in areas where it accumulates. This study introduces “plasticlusters”, a new form of floating debris agglomeration found in the Yasmine Hammamet marina (Tunisia, North-Africa), loosely attached to pontoon ropes around the water surface level. The analysis of two samples revealed that they were formed primarily by average 2.11 mm polystyrene fragments, 3.43 mm fibers, 104 mm polypropylene and polyethylene sheets, and 122 mm decomposing seagrass leaves. They were inhabited by several taxa, including at least 2 cryptogenic and 5 non-indigenous species (NIS). Unlike other plastic formations, plasticlusters provide a novel and potentially temporal microhabitat to fouling assemblages due to their loose and unconsolidated structure which, combined with marinas being NIS hubs, could enhance NIS dispersion. The results of this study raise concerns about the combined ecological effects of debris accumulation and biocontamination inside marinas.
... There are also other recorded routes of introduction, although they are not as impactful: the introduction of species used as fishing bait, transport by floating objects, transport by tourists, transport of sediments between river basins, or the introduction intended for consumption as food [30,31]. ...
... Moreover, the popularity of the Iberian coastline for tourism and recreational activities leads to increased human movement. These activities can inadvertently facilitate the spread of non-native algae, either through direct transport or by disturbing native habitats [30]. ...
The term “non-indigenous species” (NIS) describes creatures that have colonized previously unoccupied parts of the globe. They have enormous ecological and economic problems everywhere because of their expanding presence. The success of biological invaders in this setting has recently been a hot topic. Of the thousands of marine NIS that have been introduced all over the world, seaweeds (marine macroalgae) are a significant part. Global investigations conducted over the past ten years have identified >277 species of invasive seaweeds. More than 100 invasive species of seaweed have been found in Europe, and the northeastern Atlantic is especially renowned for harboring a large number of these species. The main NIS of seaweeds that can currently be found in the waters (Atlantic and Mediterranean) of the Iberian Peninsula (including the respective archipelagos) will be the topic of this revision, which will examine the processes of seaweed invasion from their introduction stage and introduction vectors to their invasive success. In order to demonstrate how these species, which are endangering the ecosystem, can be an excellent environmental resource of bioactive compounds with high industrial potential and high socioeconomic revenue, their environmental management of NIS as well as their potential uses as biofertilizers, bioactivities, feed, and food were also addressed.
... The progress of human activities in marine and coastal regions, including urban areas, construction of industries, and ports, have contributed to the release of numerous pollutants to marine environments (Kiessling et al., 2015;Campbell et al., 2017;Póvoa et al., 2021). Among them, marine anthropogenic litter is particularly generated in large quantities (De-la-Torre et al., 2021a). ...
... Among marine litter, plastic (styrofoam and ropes) and wood, are mentioned as the major transport vectors for marine organisms (Carlton and Fowler, 2018;Rech et al., 2018b;Battaglia et al., 2019;Shabani et al., 2019;Mantelatto et al., 2020a;De-la-Torre et al., 2021b;Póvoa et al., 2021Póvoa et al., , 2022Lacerda et al., 2022;Rizzo et al., 2022;Subías-Baratau et al., 2022). The substrates harboring marine biota are generally of anthropogenic origins, such as plastics and processed timber (Campbell et al., 2017;Rech et al., 2018a;Póvoa et al., 2021). These substrates can drift for long periods and reach great distances across the ocean basins (Goldstein et al., 2014;Rech et al., 2018b;García-Gomez et al., 2021;Póvoa et al., 2021). ...
The existence of floating marine litter in marine environments enhances the potential for the transport of fouling organisms using these substrates as vectors. In this study, we examined the fouling organisms on different types of litter stranded on two beaches of the Moroccan Mediterranean. The study revealed 13 fouling species belonging to 8 phyla (Arthropoda, Bryozoa, Annelida, Mollusca, Cnidaria, Echinodermata, Chlorophyta, and Ochrophyta) on marine litter. Rafting vectors were almost exclusively made up of plastics and could mainly be attributed to land-based sources. The most common fouling species were the crustacean Lepas pectinata, Lepas anatifera, Perforatus perforatus, and bryozoan species. More taxa were found on large litter than on small litter. Relative substratum coverage was highest for bryozoan sp. (31.0 %), green algae (29.0 %), Lepas anatifera (21.42 %), Lepas pectinata (17.8 %), and Perforatus perforatus (17.46 %). Our results suggest that the growing generation of plastic litter may enhance the probability of the introduction of non-native species into the Moroccan Med-iterranean. Therefore, monitoring efforts are needed to identify vectors and the arrival of novel invasive species in this area.
... Those substrates originate from human activities on land as well as at sea, including fishing, aquaculture, and navigation (Campbell et al., 2017). ...
... Until very recently, the dislocations of fouling organisms were limited to biotic substrates such as tree trunks, algae, shells and other rigid animal structures, collectively considered biogenic substrates (Jokiel, 1984;Aliani and Meloni, 1999;Barnes, 2002;Barnes, 2004;Barnes and Milner, 2005;Astudillo et al., 2009;Kiessling et al., 2015;Campbell et al., 2017). Transport on diverse substrates intensified with the expansion and reach of commercial maritime routes, especially in the 20th century and the beginning of the current century (Carlton, 1985;Shenkar and Rosen, 2018). ...
One of the underestimated consequences of marine litter presence on marine environment is the transportation of fouling species on detritus-a process known as rafting. We undertook a review of articles concerning rafting published between 1970 and 2020 to identify patterns and potential areas of study that could contribute to directing future research. We observed in 53 publications an increase in rafting studies from the 1990s but fewer studies have been undertaken in the Southern Atlantic. The main fouling organisms were algae, barnacles, bryozoans, mollusks and polychaetes. The transport of those organisms over time and distances, and the volumes of material transported, have been very irregular, reflecting oceanic movements and detritus generating events acting at local, regional, or trans-oceanic scales. No standardized methodologies for collecting marine litter and identifying and quantifying their fouling were observed, but are suggested in this review, to allow more accurate future comparisons among different studies.
... For example, raft material, surface roughness, and color affect biofilm formation and larval settlement and may, therefore, be particularly important during early successional stages (Devakie and Ali, 2002;Bravo et al., 2011;Pinochet et al., 2020). The source of a litter item can also be of importance, as some items from sea-based activities, like aquaculture buoys, can already be fouled and carry a variety of coastal and nonnative species when they get lost (Astudillo et al., 2009;Campbell et al., 2017;Rech et al., 2018c). Community richness and composition are influenced by habitat complexity, in this case, the structural complexity of the floating items, offering shelter and/or structures to cling to (Dean and Connell, 1987;Thiel and Gutow, 2005b). ...
... Buoys have often been anchored in the water and accumulated considerable epibiont communities before getting lost, especially in coastal zones, with high invertebrate abundances and diversities (e.g. Kerckhof and Cattrijsse, 2001;Astudillo et al., 2009;Campbell et al., 2017;Rech et al., 2018c). Both buoys and large fishing crates have a rather small relative surface area (in relation to volume), and can, therefore, support substantial fouling communities without sinking (see Ryan, 2015). ...
The hyper-oligotrophic waters of the South Pacific Subtropical Gyre (SPSG) and the productive coastal Humboldt Current System (HCS) constitute an extreme nutrient gradient in the eastern South Pacific Ocean.Rich and dense fouling communities are known from floating objects in the HCS, but they have not been studied in the SPSG and
it is not known which factors are influencing their richness and abundance. Here we present the first extensive study of rafting by marine invertebrates on floating anthropogenic debris in the eastern SPSG. We compared the effect of 9 raft-related categorical predictors on epibiont richness and fouling cover. Raft complexity was
the most important predictor of richness. Fouling was dominated by thin crusts and biofilms, with more advanced communities only observed on few items. Fouling cover could not be predicted by any of the categorical factors tested. However, when tested as continuous predictors, raft volume and surface area were significantly correlated with both cover and richness. The most frequently encountered epibionts were common pelagic rafters, particularly Lepas spp., Planes spp., and Jellyella spp. Low fouling cover suggests that the SPSG's hyperoligotrophic conditions strongly limit fouling growth, while the low frequency of coastal taxa points to the HCS/SPSG nutrient gradient acting as a filter for such organisms.
... A New Zealand study identified both native and non-indigenous species were associated with plastic rope debris originating from aquaculture facilities. 131 The potential biosecurity threat increases for beaches with built structures such as jetties and boat ramps close to shore, that facilitate debris accumulation. 131 Scientists have started a five-year research project investigating how microplastic contamination affects our native species, environment, tāonga and health in Aotearoa New Zealand. ...
... 131 The potential biosecurity threat increases for beaches with built structures such as jetties and boat ramps close to shore, that facilitate debris accumulation. 131 Scientists have started a five-year research project investigating how microplastic contamination affects our native species, environment, tāonga and health in Aotearoa New Zealand. 132 As part of this project, scientists from the Cawthron Institute are investigating plastics as a biosecurity threat. ...
Evidence summary on plastics in the environment. There is growing concern about the use of plastics and their effects on the environment and human health.
This document sets out how plastics are made, used and disposed of. It also covers how plastics enter the environment and the risks plastics pose to wildlife and humans.
... Artificial habitats, such as breakwaters, host a variety of inter-and subtidal biota, but in general, do not have as rich communities as natural rocky shores (Firth et al. 2013;Aguilera et al. 2014;Strain et al. 2021). However, some artificial environments, such as aquaculture areas and ports, have high habitat complexity and are often protected by breakwaters, offering substantial potential for the acquisition of species (Campbell et al. 2017). Environments with biotic structures, like coral reefs or mangrove forests, house diverse invertebrate communities. ...
Background
Rafting of organisms on floating objects, long recognised as a key process in biogeography and evolution, has undergone tremendous change with the rapid increase of ocean litter (plastics and other human‐made materials). Resulting increases in raft longevity and abundance expand opportunities for marine species' dispersal. Here, we present a conceptual framework for the role of benthic stopovers by artificial rafts and how these likely enhance cumulative species acquisition and dispersal.
Stages of Benthic Stopovers
We define four stages of benthic stopovers: (1) landing (horizontal transport) or sinking (vertical transport), (2) retention in the benthic habitat (intertidal or subtidal), (3) colonisation by local species, and (4) re‐washing (horizontal transport) or re‐surfacing (vertical transport).
Colonisation and Dispersal From Stopovers
The fate of floating items and their attached biota depends on the interplay of local (site‐related), regional (oceanographic/climatic) and object characteristics. Available literature suggests that stopover events on shores (horizontal transport) are most likely to happen in complex natural environments like mangrove forests or rocky shores. These can trap and retain litter in the inter‐ and subtidal zone, with access to suitable rafting species. Large and highly buoyant items, with rigid surfaces resistant to breakage, are most likely to complete stopovers.
Conclusions
Stopovers can enhance colonisation and dispersal of biota by increasing both the species pool and frequency of dispersal events by litter rafts. We suggest stopovers are far more common than currently reported and play an increasing role in range dynamics, calling for innovative research to address this knowledge gap.
... These species are typically transported via maritime vectors, such as ballast water discharge and biofouling on hulls, as well as through commercial activities like aquaculture trade (Bailey et al., 2020). They possess the potential to become invasive, resulting in significant and often irreversible ecological, economic, and social consequences (Carlton and Geller, 1993;Campbell et al., 2017;Komyakova et al., 2022). While some countries have developed and enforced regulations to mitigate the risks posed by biofouling, a comprehensive understanding of how marine systems respond glogally to human pressures remains incomplete (Borja et al., 2016;Korpinen and Andersen, 2016;Ros et al., 2023). ...
Introduction
Maritime traffic and coastal urbanisation significantly contribute to the introduction and proliferation of non-indigenous species (NIS). However, the lack of information might prevent effective monitoring in data-limited regions, particularly in areas experiencing demographic growth, where monitoring biofouling communities could offer crucial insights into the dynamics of NIS invasions. This study represents a baseline characterization of the biofouling communities in the northern Saudi Arabian Red Sea (NEOM region) prior to extensive urban, industrial, and commercial development.
Methods
Samples were collected in November 2023 and February 2024 from seven sites within the region. At each site and time, three settlement structures, each with a PVC panel attached to a brick and rope, were sampled after 3-months deployment. Panels were analysed with photo quadrat analysis (PhQd), examined to manually collect sessile macroinvertebrate specimens for taxonomic identification using morphological and DNA barcoding analysis, and scraped for bulk DNA analyses using DNA metabarcoding. Five water samples were also collected for environmental DNA (eDNA) analysis. The environmental characteristics of each site were obtained by deploying temperature data loggers and through an environmental risk assessment.
Results
Community patterns observed from the PhQd and bulk DNA datasets revealed a clear separation of two sites within Sharma lagoon from the remaining sites. The eDNA analysis of seawater confirmed these spatial differences, also detecting a variation between sampling times that was not observed with the other approaches. A total of 20 NIS and 18 cryptogenic species were recorded, from which 12 were identified morphologically and the remaining detected with molecular methods only. The generally low NIS coverage confirms that the NEOM region is less affected by marine biological invasions compared to other anthropized habitats within the Red Sea. However, sites in the Sharma lagoon showed high human pressure levels and comparatively higher coverage of cryptogenic bryozoans on panels.
Discussion
This study provides the first detailed assessment of biofouling communities in NEOM, establishing a baseline and contributing to a regional species reference library for non-indigenous and cryptogenic species. As coastal development spreads, it presents both challenges and opportunities, highlighting the need for sustainable, ecosystem-based approaches to protect valuable natural areas. This baseline is essential for future monitoring of biofouling dynamics as the region develops.
... In addition, service vessels may act as vectors for the transfer of biofouling propagules between farms and adjacent ports. Finally, sea farming contributes a substantial portion of marine debris to the ocean (see Section 4.6) and along with microplastics produced by or interacting with the facility (Bowley et al., 2021), also represents a pathway for the transfer of organisms (Campbell et al., 2017). ...
The biofouling of submerged anthropogenic surfaces and factors that contribute to the spread of non-indigenous species (NIS)
have both received substantial attention from researchers, regulators and the private sector focused on understanding their
economic, social and environmental consequences. This work has informed the development and implementation of sustainable
management approaches, for the prevention of a range of harmful impacts. All marine commercial and recreational sectors deal
with biofouling and its varied but typically undesirable consequences. Similarly, almost all marine resource managers, from local
to global scale, are concerned with the threat of invasive species and their vectors. This review is an effort by the GESAMP WG 44 to
look at the interface between these two pervasive challenges.
Various strategies and tools to prevent, reduce or manage biofouling have been developed and adopted. The intent ofthese efforts
has been primarily to combat the direct negative consequences of biofouling communities on the performance and structural
integrity ofthe surfaces to which the communities attach. The potential for biofouling to be a vector for invasive species has usually
been a secondary consideration. Although the strategies, tools and associated regulatory measures are typically developed by
experts working within a specific aquatic sector, uptake of successful actions by other sectors is common.
Currently, all of the strategies, tools or regulatory measures have both strengths and limitations, which can vary greatly with
the context in which they are applied. This report first reviews the more general consequences of biofouling (Chapter 2) and the
strengths and limitations of the most common strategies, technical measures and policies for preventing and managing biofouling
(Chapter 3). This information sets the context in which to examine how effectively each commercial and recreational sector currently
can deal with biofouling, its impacts and the potential unintended consequences of antifouling or biofouling removal approaches.
This examination was conducted sector by sector (Chapter 4), because some strengths or weaknesses of each individual measure
or policy may affect suitability and performance differently in the various marine sectors. Moreover, although biofouling may
present a pathway for movement of NIS in each sector, the primary risks associated with each sector may also differ. Thus,
within Chapter 4, for each sector, the report examines which policies, measures and regulatory actions are commonly used,
the rationales for the preferences, and how these choices affect the potential for the sector to manage the risk of transfer of NIS
through biofouling. Opportunities to increase the effectiveness in preventing or reducing the transmission of invasive species
through adapting improving existing policies, measures and regulations, or adopting additional ones, are highlighted. The sectors
examined are vessels (subdivided into shipping, fishing and recreational sectors), aquaculture, marine offshore energy, offshore
renewable energy, ocean-observing infrastructure (i.e. monitoring and research instrumentation) and marine debris.
The report finds that, for each sector, there is no single ‘best solution’. Various combinations of policies, measures and regula�tions are necessary for the effective prevention or control of biofouling and NIS. Regulatory frameworks with clear standards can
contribute to managing the risk of biofouling as a pathway for the spread of invasive species but must be appropriate for the sector.
Effective frameworks also must be supported by adequate monitoring and capacity to ensure compliance, regularly updated as
additional knowledge and innovations become available, and must not cause other unintended environmental consequences.
Moreover, performance will remain context-specific even for combinations of measures, making ongoing monitoring, information
sharing within and among sectors and adaptive management essential. Some of these emergent lessons and priority knowledge
gaps are summarized in Chapter 5.
... In addition, service vessels may act as vectors for the transfer of biofouling propagules between farms and adjacent ports. Finally, sea farming contributes a substantial portion of marine debris to the ocean (see Section 4.6) and along with microplastics produced by or interacting with the facility (Bowley et al., 2021), also represents a pathway for the transfer of organisms (Campbell et al., 2017). ...
... Importantly, One Health initiatives have, to date, failed to capture the commonalities among the risks faced by human, animal, plant, and ecosystem health and especially the important role that pathway management can play in reducing risks. For example, invasive alien threats to human, animal, plant, and ecosystem health are introduced to new regions as a result of hull fouling (Hewitt et al. 2004b , Drake andLodge 2007 ), ballast water and sediments (Carlton 1985, Outinen et al. 2021, sea chests and anchor lockers (Hewitt et al. 2004a ), canals (Katsanevakis et al. 2013 ), rafting on anthropogenic debris (Campbell et al. 2017, Rech et al. 2018, the movement of aquaculture gear and stock (Drake and Lodge 2007 ), the deliber-ate movement of species considered beneficial for fisheries (either commercial or recreational; Xiong et al. 2023 ), the movement of bait (Fowler et al. 2016 ), the ornamental trade (Ebner et al. 2020 ), and tourism (Bothwell et al. 2009 ). Many taxa are associated with multiple pathways (Hewitt et al. 2004a, Bailey et al. 2020, such that methods that focus on a single pathway are likely to have limited value. ...
Understanding the magnitude of biosecurity risks in aquatic environments is increasingly complex and urgent because increasing volumes of international shipping, rising demand for aquaculture products, and growth in the global aquarium trade, are accelerating invasive alien species spread worldwide. These threats are especially pressing amid climate and biodiversity crises. However, global and national biosecurity systems are poorly prepared to respond because of fragmented research and policy environments, that often fail to account for risks across sectors or across stakeholder needs and fail to recognize similarities in the processes underpinning biological invasions. In the present article, we illustrate the complex network of links between biosecurity threats across human, animal, plant, and environment sectors and propose a universal approach to risk assessment. One Biosecurity is a holistic, interdisciplinary approach that minimizes biosecurity risks across human, animal, plant, algal, and ecosystem health and is critical to reduce redundancy and increase cross-sectoral cohesion to improve policy, management, and research in aquatic biosecurity.
... Introductions of non-native marine species have increased in recent decades (Teixeira et al., 2020), mainly due to human activities, such as shipping and aquaculture (Campbell et al., 2017). Bays that host ports and waterway terminals, such as Sepetiba Bay, often harbor several exotic species that are carried by encrustation on vessels, intensive marine traffic, or ocean rafting (Rocha et al., 2013;Bumbeer and Rocha, 2016). ...
Members of several polychaete families inhabit rocky shores, including syllids, serpulids, eunicids, nereidids, and sabellids. The primary studies on consolidated substrates conducted in Sepetiba Bay (Rio de Janeiro, Brazil) date back to 2004, with multiple taxonomic studies having been carried out since then. In this study, we present an updated checklist on polychaetes from hard substrates in Sepetiba Bay, together with an identification key for the species. We also discuss the status and distribution of certain species along the Brazilian coast. Myrianida pachycera, Branchiomma bairdi, Branchiomma coheni, and Branchiomma conspersum represent new occurrences in Brazil. We extend the distribution of Proceraea anopla to Southeastern Brazil, and report 33 new records for Sepetiba Bay. We identify Halosydna glabra, Oxydromus obscurus, Oxydromus pugettensis, Marphysa sanguinea, Lysidice ninneta, Spirobranchus americanus, Polydora ciliata, Pseudonereis variegata, Nereis cf. oligohalina, and Schistomeringos rudolphi as requiring taxonomic revision, all of which have been recorded previously in Sepetiba Bay. However, the specimens we examine in this study differ from the original descriptions, indicating that a more comprehensive assessment of the respective species is needed along the Brazilian coast.
Keywords:
Polychaeta; Sclerobionts; Rocky shores; Invasive species; New occurrences
... The latter endangers external ecosystems through the arrival of plastic item rafts, allegedly harboring non-indigenous invasive species (Rech et al., 2016;Miralles et al., 2018;Póvoa et al., 2021;Cesarini et al., 2022;Snigirova et al., 2022;Mghili et al., 2022;Brandler and Carlton, 2023;Gallitelli et al., 2023;Kannan et al., 2023). There are numerous examples of medium-and long-distance transport of invertebrates rafted on marine litter, such as hydrozoans, barnacles, bryozoans, gastropods, bivalves, and polychaetes (Campbell et al., 2017;Garcia-Vazquez et al., 2018;Rech et al., 2018a;Węsławski and Kotwicki, 2018;Shabani et al., 2019;Ibabe et al., 2020;Crocetta et al., 2020;Rumbold et al., 2020;Rech et al., 2021;Mghili et al., 2022;Kannan et al., 2023). Thereafter, once established in a foreign environment, invasive non-indigenous species may result in the relocation of native species, including endemic and threatened species, and are very difficult to uproot (Goldstein et al., 2014;Miralles et al., 2018;García-Gómez et al., 2021). ...
Today, the world is increasingly concerned about marine litter and its interaction with marine biodiversity. However, knowledge concerning the fouling organisms associated with marine litter is very limited in many of the world's marine environments. In this survey, we investigated biofouling on different types of marine litter washed up on all the coasts of the central Atlantic of Morocco. The findings revealed 21 fouling species belonging to 9 phyla (Arthropoda, Mollusca, Echinodermata, Annelida, Bryozoa, Porifera, Chlorophyta, Ochrophyta, and Ascomycota). More specifically, frequently observed fouling species include Mytilus galloprovincialis, Balanus laevis, Megabalanus coccopoma, and Pollicipes pollicipes species. Large marine litter items recorded the highest colonization of marine organisms in comparison to small ones. The frequency of occurrence (FO) of the species most commonly fouled on all coasts was Perforatus perforatus (FO = 48.60), followed by Mytilus galloprovincialis (FO = 45.80), Balanus trigonus (FO = 32.05), Balanus laevis (FO = 30.25), Megabalanus coccopoma (FO = 25.25), Bryozoa species (FO = 19.40), Spirobranchus triqueter (FO = 18.18), Lepas pectinata (FO = 14.45), and Pollicipes pollicipes (FO = 13.05). The majority of the species registered in this study are sessile. Substrate coverage by fouling taxa was significantly different between plastic substrate and other types of marine litter. Likewise, this study revealed that the proportion of fouling organisms is higher on rough surfaces. Overall, this research could be crucial to understanding the little-known subject of marine litter and its colonization by marine biota. Given that these marine litters can act as vectors and cause ecological, biogeographical, and conservation issues in the marine environment, minimizing the quantity of anthropogenic litter reaching the Moroccan Atlantic could significantly reduce its accumulation on the sea surface and seabed, thereby reducing the risk of invasion by non-indigenous species.
... Three geographical origins were recognized: the Philippines, foreign or origin unknown. Items were grouped into plastic types (bags, bottles, etc.) using the UNEP/IOC classification scheme (Cheshire et al., 2009), a universal method that facilitates between-study comparisons (e.g., Williams et al., 2016;Campbell et al., 2017). ...
Complex networks of above-ground roots and trunks make mangrove forests trap plastic litter. We tested how macroplastics relate to tree biomass, root abundance, mangrove geomorphology and river mouth proximity, surveying landward and seaward margins of seven forests in the Philippines, a global hotspot for marine plastic pollution. Macroplastics were abundant (mean ± s.e.: 1.1 ± 0.22 items m − 2 ; range: 0.05 ± 0.05 to 3.79 ± 1.91), greatest at the landward zone (mean ± s.e.: 1.60 ± 0.41 m − 2) and dominated by land-derived items (sachets, bags). Plastic abundance and weight increased with proximity to river mouths, with root abundance predicting plastic litter surface area (i.e., the cumulative sum of all the surface areas of each plastic element per plot). The study confirms rivers are a major pathway for marine plastic pollution, with mangrove roots are the biological attribute that regulate litter retention. The results suggest land-based waste management that prevent plastics entering rivers will reduce marine plastic pollution in Southeast Asia.
... However, globally enforced frameworks are lacking. Similarly, the emerging vector of marine litter, which has been gaining relevance over the last decade, requires attention because of the global distribution, buoyancy, and high levels of colonization that plastic litter can support, which facilitates the transport of species to nonnative regions (Barnes 2002, Campbell et al. 2017, Carlton et al. 2017, Rech et al. 2018, Audrézet et al. 2021. International conventions and legislation must be evaluated for efficiency with scientifically validated data while clearly outlining expected actions and an appropriate timeline for implementation by participating nations (figure 2 ). ...
Managing marine nonindigenous species (mNIS) is challenging, because marine environments are highly connected, allowing the dispersal of species across large spatial scales, including geopolitical borders. Cross-border inconsistencies in biosecurity management can promote the spread of mNIS across geopolitical borders, and incursions often go unnoticed or unreported. Collaborative surveillance programs can enhance the early detection of mNIS, when response may still be possible, and can foster capacity building around a common threat. Regional or international databases curated for mNIS can inform local monitoring programs and can foster real-time information exchange on mNIS of concern. When combined, local species reference libraries, publicly available mNIS databases, and predictive modeling can facilitate the development of biosecurity programs in regions lacking baseline data. Biosecurity programs should be practical, feasible, cost-effective, mainly focused on prevention and early detection, and be built on the collaboration and coordination of government, nongovernment organizations, stakeholders, and local citizens for a rapid response.
... Indeed, hull fouling is the most significant vector of the introduction of marine NIS in the Madeira Archipelago coastal waters (Canning-Clode et al. 2013a;Ramalhosa et al. 2014Ramalhosa et al. , 2017aRamalhosa et al. , 2017bRamalhosa et al. , 2019Ramalhosa and Canning-Clode 2015;Souto et al. 2018). Moreover, offshore aquaculture activities facilitate the local dispersion of NIS (Nunes et al. 2014;Campbell et al. 2017), posing a serious environmental threat to biodiversity and ecosystem function (Mack et al. 2000;Png-Gonzalez et al. 2021). Aquaculture artificial substrates may serve as stepping stones, offering novel niches for opportunistic colonizers, including NIS, favoring their dispersal (De Mesel et al. 2015) and supplying substrate to establish other NIS (Rius et al. 2011;Png-Gonzalez et al. 2021). ...
Hull fouling is considered to be the most significant vector of introduction of marine non-indigenous species (NIS) in the Madeira Archipelago (NE Atlantic) because these islands provide a vital passage route for many ships. The transfer of species between boat hulls and artificial substrates in marinas is known to be high. Bryozoans are among the most common groups of marine invertebrates growing on this type of substrate. In recent years, significant advances have been made in our knowledge about the biodiversity of bryozoans in the Madeira Archipelago. Nonetheless, the currently recognized numbers remain far from reflecting the actual bryozoan species richness. In this context, we examine bryozoan samples stemming from NIS monitoring surveys on artificial substrates along the southern coast of the Madeira Archipelago, in four recreational marinas and in two offshore aquaculture farms. This has yielded new information about ten bryozoan species. Two of them, Crisia noronhai sp. nov. and Amathia maderensis sp. nov., are described for the first time, although at least the first one was previously recorded from Madeira but misidentified. Bugula ingens, Cradoscrupocellaria insularis, Scruparia ambigua, and Celleporaria brunnea are recorded for the first time in Madeira. Moreover, the material of C. brunnea was compared with the type, and a biometric analysis was performed with material from the Atlantic and Mediterranean. All samples identified as C. brunnea in both regions are the same species, and the variations described in the literature apparently reflect high intracolonial variability. Finally, we provide new information for the descriptions of 4 additional bryozoans, namely, Crisia sp. aff. elongata, Cradoscrupocellaria bertholletii, Scrupocaberea maderensis, and Tricellaria inopinata.
... Locations further from shore require more expensive infrastructure and resources, which may limit the locations where mariculture can feasibly operate. These offshore locations have additional sustainability challenges such as increased requirements for fuel and subsequent GHG emissions (Morro et al., 2022) and potential for greater marine debris (Campbell et al., 2017) and megafauna interactions as a result of more extensive cage and anchor systems (Barrett et al., 2019). The environmental impacts of marine farms (e.g., pollution, disease outbreaks, and eutrophication), both near-and offshore, are a concern for the expansion of the industry (Asche et al., 2010(Asche et al., , 2018Islam, 2005;Leung and Bates, 2013). ...
... The ongoing increase in anthropogenic activities in the marine environment is critical for facilitating the introduction and dispersion of non-indigenous species (NIS) [1,2], which are considered a major threat to global biodiversity and ecosystem function [3,4]. Among NIS, some species show an invasive behavior that often implies severe impacts on the ecosystem through rapid increases in their abundance and the extent of their distribution [5], also involving socio-economic and health impacts [6]. ...
The introduction of new non-indigenous species (NIS) in Spanish marine waters is addressed under Descriptor 2 of the European Union’s Marine Strategy Framework Directive. National baseline inventories of NIS have been compiled and updated for the three subregions (Western Mediterranean Sea, WMED; Bay of Biscay–Iberian Coast, ABI; Macaronesia, AMA) with data from 1800 to 2021. An overall of 574 species were identified with an alien, cryptogenic, crypto-expanding, or debatable status, mostly invertebrates (~65%) and primary producers (~22%). Of 412 alien species, 80.51% were reported in ABI, 67.82% in WMED, and 66.67% in AMA. Cryptogenic species are more abundant in the WMED (25.25%), compared to AMA (19.77%) and ABI (18.46%). ABI harbors more established species (62.56%) than AMA (45.2%) and WMED (43.56%), contrary to casual records (AMA 31.64%, WMED 23.76%, ABI 13.85%). Invasive species are more abundant (14.36%) in WMED. The ‘transport-stowaway’ pathway accounted for 142 (79.33%), 123 (67.58%), and 169 (85.21%) records in WMED, ABI, and AMA, respectively. The second most common pathway was ‘transport-contaminant’ related to mariculture (~10% of the total), prevalently in ABI with 42 species (23.08%). The Canary Islands stand out for species introduced through oil platforms from throughout the world. ‘Unaided’ was a relevant pathway of secondary introduction into the WMED, particularly of Lessepsian species progressing westwards. Temporal trends in newly introduced species show similar behavior among subregions.
... For instance, Forrest et al. (2009) concluded that the introduction and spread of pest species is a potentially important, but often overlooked, consequence of oyster cultivation. Aquaculture infrastructure and gear have been shown to harbor high incidences of non-native species compared to native habitats ) and can be a source of marine debris that may transport such species over extensive distances, further contributing to their spread (Astudillo et al. 2009) and creating a biosecurity risk (Campbell et al. 2017). However, Iacarella et al. (2019) indicated that aquaculture gear is an unlikely vector for non-native species in the northeastern Pacific Ocean because of limited movement of shellfish gear and existing cleaning practices. ...
Provides conservation recommendations to state and federal agencies planning actions that may adversely affect EFH.
... Plastic litter are primarily introduced into aquatic ecosystems by land-based sources, such as recreational activities, rivers, urban runoff, storm drains, sewage discharges, plastic manufacturing plant effluents, landfills, or recycling points (Rech et al., 2014;Galgani et al., 2015;Jambeck et al., 2015;Gunasekaran et al., 2022). In addition, plastic litter can be introduced through marine sources, such as fishing and aquaculture (Campbell et al., 2017), ultimately, accumulating in aquatic ecosystems around the world, from coastal areas to deep waters (Hammer et al., 2012). ...
The introduction and transport of marine invasive species into new environments are a great threat to biodiversity and ecosystem services with potential economic repercussions. There are several routes and mechanisms by which alien species are transported and dispersed in the marine environment (shipping, waterways, and aquaculture). Each year, millions of tons of plastic enter the ocean. The presence of floating marine litter in marine environments provides a substrate for marine organisms and may increase the potential for the transport of alien species. Research on the role of marine litter in the introduction of alien marine species has grown exponentially in recent years. In this study, studies examining the transport and dispersal of alien species by marine litter are reviewed. In this review, we identified 67 alien species associated with marine litter. The most recurrent alien phyla found on marine litter are Arthropoda (29 %), Mollusca (23 %), Bryozoa (19 %), Annelida (7 %) and Cnidaria (5 %). Plastic appears to be more efficient in transporting alien species than by natural means. Their characteristics (buoyancy and persistence) allow them to be widely dispersed throughout all ocean compartments. Thus, plastics may act as a primary vector, carrying organisms to remote areas but can also facilitate the secondary spread of alien species between points of invasion. Despite the growing number of studies on this subject, much work remains to be done to understand the roles of plastics in the introduction of alien species and to develop solutions to mitigate the issue.
... In addition, it is likely that the percentage of multiple introductions (34%) has been strongly underestimated due to knowledge gaps in actual introduction pathways and vectors. Accounting for understudied pathways, such as the aquarium and bait trades, recreational boating and anthropogenic marine litter (e.g., [17,[57][58][59]), could also lead to new insights and priorities for NIS monitoring and management. ...
Biological invasions are one of the main global threats to biodiversity in terrestrial, freshwater and marine ecosystems worldwide, requiring effective inventorying and monitoring programs. Here, we present an updated list of non-indigenous species in French marine and transitional waters. Focused on eukaryote pluricellular species found throughout the three metropolitan French marine regions (Western Mediterranean Sea, Bay of Biscay and the Northern Seas), a total of 342 non-indigenous, including 42 cryptogenic, species are listed as having been introduced since the 13th century. The majority of the species originated from the temperate Northern Pacific. They mainly arrived through both ballast and hull fouling and also are associated with shellfish farming activities. Most of them have been introduced since the 1970s, a time when maritime and aquaculture trade intensified. Despite important human-aided opportunities for species transfer between the three marine regions (for instance, via recreational boating or aquaculture transfers), only a third of these NIS are common to all regions, as expected due to their environmental specificities.
... Several approaches to identify the origin of marine debris have been developedthese include the: 1) use of natural distribution patterns of foulant species and their biological traits to inform origins (Hoeksema et al., 2012); 2) exploration of taxonomic profiles of fouling communities on debris on beaches close to areas of high maritime activity, such as ports, where NNS have been found (Miralles et al., 2018;Ibabe et al., 2020;Rech et al., 2018); 3) linking biological traces of animals on debris to local sites (e.g. debris was attributed to a local mussel farm source following detection of attached byssal threads on debris in Campbell et al. (2017)); and 4) examination of the characteristics of the debris itself (Quigley and Hill, 2015;Rumbold et al., 2020). Occasionally, the origin of biofouled debris can be traced using meteorological information following a large-scale weather event or natural disaster such as the 2011 tsunami in Japan (García-Gómez et al., 2021). ...
The long-distance transfer of non-native, potentially invasive species via floating marine debris is an increasing threat to biodiversity and conservation efforts. To address the lack of understanding around mechanisms and pathways of species transfer via marine debris, a novel modelling approach was applied to recreate the likely trajectory and source of a large piece of debris fouled by non-native species collected from UK marine waters. This approach applied the Oil Spill Contingency and Response (OSCAR) simulation tool, an adapted oil spill modelling programme, which was informed by a combination of biological trait information for the foulant species, marine debris characteristics and hydrodynamic data. The modelling output suggested an origin in the Western Atlantic, a scenario concurrent with the known distribution of the foulant species. This modelling approach represents a valuable tool with which to determine the origin and trajectory of invasive species transferred via marine debris.
... Further domestic spread of fanworm in New Zealand has most likely been facilitated by the movement of infested vessels among coastal locations. In addition to being able to survive in sea chests and ballast water, this species also overgrows coastal infrastructure, including moorings and aquaculture facilities, which in turn become stepping stones for secondary spread via regional shipping and movement of marine equipment (Campbell et al., 2017;Floerl et al., 2009;Growcott et al., 2017;Hopkins and Forrest, 2008). ...
Biofouling invasive species cause economic harm to shellfish aquaculture and require effective management strategies. Therefore, a better understanding of the life cycle and spread of key pest species for more efficient surveillance approaches is needed. The main purpose of this study was to assess effectiveness of detecting the invasive Mediterranean fanworm, Sabella spallanzanii, at mussel farms using environmental DNA and RNA (eDNA/ eRNA) approaches and compare the results to visual surveys that were undertaken to detect presence, settlement seasonality and growth of the fanworm on different settlement substrates. Monthly biofilm and seawater samples were taken around three mussel farm sites and tested for S. spallanzanii eDNA and eRNA signals
using a species-specific droplet digital PCR (ddPCR) assay. Occupancy modelling applied on the eDNA-based detections indicated the fanworm's probability of detection at 90% of all sampled locations regardless of month or depth. Environmental DNA ddPCR copy numbers were highly variable but were detected in every monthly sample. Specifically, month and sampling matrix (seawater or biofilm) contributed significantly to predicting the eDNA signal strength (p < 0.001). Unfortunately, eRNA detections were very low and only ten out of 48 samples yielded a positive eRNA detection. Observations from settlement substrates showed that it took around 8 months for the fanworms to grow to ~5 cm in length and they preferred to settle on more complex rather than smooth surfaces. Our results suggest that a species-specific eDNA/RNA ddPCR assay at a mussel farm, followed by further visual or settlement monitoring could aid increased vigilance for detecting the arrival of newly invasive species at an early settlement stage.
... For example, information on the relative susceptibilities of substrates in bivalve aquaculture (buoys, long-lines, and mussel socks) to fouling NIMS can provide insights for the development of costeffective, customized management strategies that include stakeholder participation to contain the spread of invasive species while monitoring for new species introductions (Sievers et al., 2014). These substrates are very important for the dispersal of NIMS by rafting in artificial structures and the accumulation of marine debris from aquaculture facilities (Campbell et al., 2017;Rech et al., 2018;Audrézet et al., 2021). ...
Invasive, fouling species increase management costs and reduce mussel growth, which jeopardizes mariculture. We studied the distribution of eight invasive species in Santa Catarina, the leading mussel producer in Brazil. Our goals were to determine their spatial distribution and prevalence on farm structures (buoys, long lines, and mussel socks), as well as understand the relevance of propagule pressure (recruitment), port distance, and area of the farm in this distribution. Although present in all sites, adult and recruits distribution were spatially restricted, showing that species might have a metapopulation structure. The most prevalent species were the ascidian Styela plicata, the barnacle Megabalanus coccopoma, the bryozoan Schizoporella errata, and the polychaete Branchiomma luctuosum. Recruitment was the main driver of three species distribution while distance to port explained only one species distribution. Based on those results, we discuss policy options, management, and regulation enforcement, that can be used in the mussel aquaculture elsewhere.
... Small-or large-scale rafting can be responsible for the introduction of non-indigenous species in marine environments such a coral reefs, rocky shores and sandy beaches. Organisms dispersed by rafting can affect the structure and functioning of communities in these ecosystems, differentiating them from the original composition, representing a risk to biodiversity and ecosystem health (Campbell et al., 2017;Póvoa et al., 2021). Several studies have been carried out around the world addressing the presence of fouling organisms in litter deposited on sandy beaches (Goldstein et al., 2014;Fazey and Ryan, 2016;Rech et al., 2016;Rech et al., 2018aRech et al., , 2018bRech et al., , 2018cPóvoa et al., 2021). ...
The presence of floating marine anthropogenic litter in marine environments increase the possibility of transportation of fouling organisms using these substrates as a vector, mainly for those species with close affinities to artificial substrates. The objectives were to qualitatively and quantitatively report anthropogenic litter and its associated fouling groups arround Ilha Grande Bay (IGB). Litter was collected, classified and examined for the presence of fouling organisms on beaches located at two different levels of wave exposure during rainy and dry seasons. The types of litter do not differ among beaches, and the highest density and cover of fouling were reported on exposed beaches due the currents, winds, and storm waves. Bryozoans, barnacles, polychaetes, and mollusks were the most frequent fouling groups observed in litter and represents a potential vector for the dispersion of species in the IGB and adjacent coastal areas.
... If discarded or lost, they represent a significant choking or entanglement hazard for wild fish, seabirds and marine mammals (e.g., Hinojosa & Thiel 2009). These materials could also act as vectors for non-indigenous species (e.g., Campbell et al. 2017) and contribute to the wider issue of plastic pollution in the marine environment. As with all other forms of aquaculture in Aotearoa New Zealand, a proper and wellregulated waste management programme to control all potential waste products is necessary. ...
The environmental effects of harvesting wild seaweed and cultivating it on farms were reviewed to inform the development of an Ecosystem-Based Management (EBM) framework to guide the progression of the Aotearoa New Zealand seaweed sector. Growth of seaweed aquaculture would allow the scale of the seaweed industry to increase without placing pressure on wild populations and provide greater control over the consistency and quality of the product. While the potential for seaweed aquaculture to supply ecosystem services beyond the provision of biomass is often promoted as a key benefit of seaweed farming, the delivery of these services is highly dependent on scale and context. Seaweed farming is considered to have a lower environmental risk than most other forms of aquaculture. Genetic interactions with wild populations, disease and marine pests, and wildlife entanglement pose the greatest environmental risk. The site specific nature of many of the benefits and risks, and the associated uncertainty about their effects, highlights the importance of developing an EBM framework for the seaweed sector in Aotearoa New Zealand.
... Non-indigenous species (NIS) are described as species which have been introduced to locations outside of their natural range as a result of human-mediated transport. In the marine environment, species are transported from their native regions to new locations either unintentionally by anthropogenic vectors such as shipping, live food and bait trade, man-made corridors (such as the Suez Canal) and ocean debris, or intentionally for purposes such as aquaculture (Bax et al., 2003;Hulme Philip, 2009;Katsanevakis et al., 2013;Bailey, 2015;Campbell et al., 2017;Therriault et al., 2018). If the species can survive the novel conditions, they can become established and form self-sustaining populations which may further spread from these points of introductions to new locations (Eno et al., 1997;Manchester & Bullock, 2000;Jensen et al., 2004;Hellmann et al., 2008). ...
Contemporary climate change (CCC) and non-indigenous species (NIS) are two of the biggest threats to global biodiversity and together are expected to drive a rapid global redistribution of species by the end of the century. Although understanding the interaction between NIS and CCC is crucial for the management of native ecosystems, forecasting future changes remains a significant challenge. It is thus recognised that understanding the physiological mechanisms that shape distributions and promote NIS spread is necessary to make robust forecasts under CCC. In this thesis, novel experimental and ecological niche modelling (ENM) techniques were combined to explore how the highly successful NIS, the Pacific oyster Magallana gigas, may be affected by end-of-the-century environmental conditions. The present research has shown during long-term exposure that M. gigas individuals were physiologically tolerant to CCC conditions predicted for the end of the century. It was evident that M. gigas has a broad environmental tolerance and have undergone rapid niche shifts during introduction that have likely facilitated its current rapid global spread. In addition, both correlative and mechanistic ENMs predicted that M. gigas will undergo a poleward range expansion by the end of the century. Modelling with inter-individual variability showed complex geographical changes in life-history traits in response to CCC. It was apparent that both correlative and mechanistic ENMs can complement each other and provide a unique insight into the predicted changes in species' niches under environmental change.
This thesis presented the first long-term, multi-factor mesocosm study of M. gigas, tested the differences between popular niche shift frameworks and presented the first bioenergetic model combining inter-individual variability and environmental variability to predict species responses to CCC across large geographical areas. Taken together, a combination of techniques has produced robust predictions forecasting the continued survival and spread of M. gigas under end-of-the-century CCC.
... While these areas may appear as discrete objects on a GIS map, in reality their impact may spread much further. For example, offshore windmills and mariculture both have a visual impact, potentially also from land, and mariculture creates biological changes in water, as well potentially producing debris that can end up on the coast (Campbell et al., 2017). It is impacts like these which were perceived by the citizens and members of the local councils in Djursland as threatening the planning decisions made on land regarding tourism activities (Danielsen, 2018;Hansen, 2019). ...
Denmark is currently producing their first Maritime Spatial Plan, as required by the European Union’s Maritime Spatial Planning Directive 2014/89. This article investigates the Danish approach to governing land-sea interactions, exploring the impacts of various institutional and procedural factors on the practice of planning at the land-sea interface in Denmark. We find that in Denmark, the MSP process has priority over the terrestrial planning system, that there is a complex institutional set-up with a lack of integration between the maritime and terrestrial planning systems, and that there exist differing perspectives about the importance of certain industries leading to conflicts.
... Here, we extend that definition to macroorganisms attached to any solid litter and to any aquatic environment such as the salt marshes, as coastal systems are now widely contaminated. This association has led to many consequences such as the colonization of engineered structures and transport of exotic species (Campbell et al., 2017). Therefore, it has become essential to understand the factors influencing this association in order to prevent unwanted outcomes. ...
The presence of solid litter and its consequences for coastal ecosystems is now being investigated around the world. Different types of material can be discarded in areas such as salt marshes, and various fouling organisms can associate with such items forming the Plastisphere. This study investigated the distribution of solid litter along zones (dry, middle, flooded) of a salt marsh environment in the Patos Lagoon Estuary (South Brazil) and the association of biofouling organisms with these items. Solid litter quantities were significantly higher in the dry zone when compared to the middle and flooded zones, showing an accumulation area where the water rarely reaches. Most items were made of plastic, as shown for many other coastal areas, and originated from food packaging, fishery and shipping activities and personal use. Although not statistically significant, there was a tendency of increased biofouling towards the flooded zone. Thirteen groups were found in association with solid litter items, mainly algae, amphipods, and gastropods. The preference for salt marsh zones, types of material and items’ colour was highly variable among groups of organisms, which can be related to their varied physiological requirements. In summary, significant plastic contamination of salt marshes of the Patos Lagoon was associated with a heterogeneous distribution of fouling communities.
... In the absence of the selective pressures from their native range, NIS route their energetic demands into growth and reproduction in the invaded areas, and are more efficient than their native counterparts Species Blossey and Notzold, 1995 hypothesized as an efficient vector of dispersal, colonization, and NIS connectivity (Campbell et al., 2017;Nikula et al., 2010;Rech et al., 2018), and facilitate marine organisms' transportation, independently of life-stage or its duration. Recent observations of the crabs Planes minutus and Liocarcinus navigator rafting on floating macro-litter highlight the role of plastic and other anthropogenic debris as rafts for dispersal across marine waters, a problem that may be enhanced through time (Tutman et al., 2017). ...
Crustaceans are amongst the most reported invaders of coastal habitats, and predatory brachyuran crabs one of the most successful marine invasive groups. They hold high tolerance to abiotic stress and their genetic, life- history, and behavioural adaptation mechanisms prompt their invasive conspicuousness. However, there is a generalized ambiguity on the specific processes that make these bioinvasions successful. No trait-related patterns have yet been found, mostly since traits attributed solely to non-indigenous crab species lack confirmation by comparison with their native counterparts and across each other. Therefore, this review discusses the available literature on fitness and plasticity of brachyuran crabs under global changes, and advances the increasing importance of addressing native versus non-native invasive species comparisons in the annals of brachyura in- vasion dynamics. Further on, integrative approaches are highlighted and proposed as innovative tools to disentangle trait-related tolerance, overall crab phenotypic plasticity and further adaptation. These indicator tools will advance the knowledge on crabs’ invasive potential, which ultimately affects upcoming population dynamics and ecosystem services, adding value to an effective management of coastal bioinvasions.
... Though a few researchers suggested that the impact of rafting on FMD is negligible compared to the effect of hull fouling or species transported in the ballast water (Lewis et al., 2005), some invasive species seem to be particularly well-adapted to the former and commonly disperse with FMD (Rech et al., 2018a). The most common encrusting organisms (Anthropoda, Mollusca, Bryozoa) found in the FMD along the Qatar coast were also commonly found in the Mediterranean Sea (Aliani and Molcard, 2003;Kiessling et al., 2015), Pacific (Campbell et al., 2017), Atlantic (Rech et al., 2018b) and Indian Ocean (Woodall et al., 2015). ...
The floating marine debris (FMD) and the associated rafting communities are one of the major stressors to ecosystem services, global biodiversity and economy and human health. In this study, assemblages of encrusting organisms on different types of stranded FMD along the west coast of Qatar, Arabian/Persian Gulf (hereafter referred to as ‘Gulf’) were examined. The analysis showed 18 fouling species belonging to 5 phyla (Annelida, Anthropoda, Bryozoa, Mollusca and Porifera) on the FMD. The most abundant fouling species were the encrusting Amphibalanus amphitrite, polychaete Spirobranchus kraussii, Bryozoan species and Megabalanus coccopoma. More number of taxa were found on larger size FMD than on smaller FMD. Some of the barnacle rafting types were found to be non-indigenous species. The central and northwest parts of the Qatar had more FMD and fouled species than in other locations. Winds and the prevailing hydrodynamic conditions (waves and currents) played an important role in the transportation and distribution of FMD and associated organisms along the west coast of Qatar. The present study confirmed that huge amount of bio-fouled FMD items, causing great damage to biodiversity, drift in the surface layer of ocean and eventually strand onto the beaches. We propose a simple, but an effective management plan for FMD and associated organisms at regional scale to restore the biodiversity, sustainability and health of the marine ecosystem in the Gulf.
... While some authors reported differences in community composition in response to spatial and seasonal factors (Oberbeckmann et al., 2014;Oberbeckmann and Labrenz, 2020), there is still a lack of geographically representative studies between oceanic regions (Table 2). For example, only one study reported NIS attachment to MPD in the South Pacific Ocean (Campbell et al., 2017), and most reports originate from the northern hemisphere (Table 2). Future work should investigate the specific patterns in community succession (e.g. ...
The introduction and spread of marine non-indigenous species (NIS) and pathogens into new habitats are a major threat to biodiversity, ecosystem services, human health, and can have substantial economic consequences. Shipping is considered the main vector for marine biological invasions; less well understood is the increased spread of marine NIS and pathogens rafting on marine plastic debris (MPD). Despite an increasing research interest and recent progress in characterizing the plastisphere, this manuscript highlights critical knowledge gaps and research priorities towards a better understanding of the biosecurity implications of MPD. We advocate for future research to (i) investigate plastisphere community succession and the factors influencing NIS propagules and pathogens recruitment through robust experimental investigations; (ii) combine microscopy and molecular approaches to effectively assess the presence of specific taxa; (iii) include additional genetic markers to thoroughly characterize the biodiversity associated with MPD and explore the presence of specific marine pests.
... Research examining commonly neglected or understudied pathways, such as the aquarium and bait trades, Internet commerce and anthropogenic marine litter (e.g. Campbell et al., 2017;Carlton et al., 2017;Chan et al., 2020;Fowler et al., 2015;Lenda et al., 2014), could lead to new insights and priorities for management of ANS. ...
Aim
The introduction of aquatic non‐indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management.
Location
Global.
Methods
We assembled an extensive dataset of first records of detection of ANS (1965–2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways.
Results
An annual mean of 43 (±16 SD) primary detections of ANS occurred—one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965–1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005–2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships’ ballast water or biofouling, although direct evidence is typically absent.
Main conclusions
This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global‐scale comparisons and sustain core measures over longer time‐scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management.
... To further complicate matters, coastal cities may themselves also generate new opportunities for dispersal between and out of urban marine ecosystems, both via creation of artificial stepping stones for hard surface dwelling organisms (see Ocean Sprawl above) and also by generating new opportunities for transport via ballast water and rafting on marine debris or tar balls. Sessile calcareous organisms such as serpulid polychaetes, bryozoans, barnacles, and gastropods are often found encrusted on floating plastic debris, and this mode of transportation has allowed, in some cases, long-range dispersal away from native habitat (e.g., Winston, 2012) and promotes invasion by nonindigenous species (Campbell et al., 2017). ...
Many of the world’s major cities are located in coastal zones, resulting in urban and industrial impacts on adjacent marine ecosystems. These pressures, which include pollutants, sewage, runoff and debris, temperature increases, hardened shorelines/structures, and light and acoustic pollution, have resulted in new evolutionary landscapes for coastal marine organisms. Marine environmental changes influenced by urbanization may create new selective regimes, or may influence neutral evolution via impacts on gene flow or partitioning of genetic diversity across seascapes. While some urban selective pressures, such as hardened surfaces, are similar to those experienced by terrestrial species, others, such as oxidative stress, are specific to aquatic environments. Moreover, spatial and temporal scales of evolutionary responses may differ in the ocean due to the spatial extent of selective pressures and greater capacity for dispersal/gene flow. Here we present a conceptual framework and synthesis of current research on evolutionary responses of marine organisms to urban pressures. We review urban impacts on genetic diversity and gene flow, and examine evidence that marine species are adapting, or are predicted to adapt, to urbanization over rapid evolutionary timeframes. Our findings indicate that in the majority of studies, urban stressors are correlated with reduced genetic diversity. Genetic structure is often increased in urbanized settings, but artificial structures can also act as stepping stones for some hard‐surface specialists, promoting range expansion. Most evidence for rapid adaptation to urban stressors comes from studies of heritable tolerance to pollutants in a relatively small number of species; however, the majority of marine ecotoxicology studies do not test directly for heritability. Finally, we highlight current gaps in our understanding of evolutionary processes in marine urban environments, and present a framework for future research to address these gaps.
... Also, the establishment of permanent moorings or barges, and movement of fishing gear can facilitate domestic spread. Invasive biofouling species including Undaria pinnatifida (Harvey) Suringar, Sabella spallanzanii (Gmelin, 1791), Styela clava Herdman, 1881 and Didemnum vexillum (Kott, 2002) have been associated with moveable aquaculture gear and debris (Forrest and Blakemore 2006;Locke et al. 2007;Fletcher et al. 2013a, b;James and Shears 2016;Campbell et al. 2017;South et al. 2017), which has contributed to their domestic spread in New Zealand and can be a nuisance/cost to the aquaculture industry. To reduce the risk of transporting invasive species on equipment, a number of treatment options can be used (Georgiades et al. 2016). ...
Multiple human-mediated pathways in the marine environment provide ample opportunities for new and potentially harmful species to spread into high-value natural areas. Often, these areas are remote and reactive measures to an invasion prove to be difficult, therefore a more precautionary and proactive approach is necessary. The Fiordland Marine Area (FMA) is largely unmodified and has a unique and productive underwater environment. Following an amendment in 2012 to the Biosecurity Act 1993 the Fiordland Marine Guardians and an inter-agency government group worked to develop and implement the Fiordland Marine Regional Pathway Management Plan (FMPP), whose overarching objective is to prevent the introduction and spread of invasive marine species to the FMA. The plan involves three key elements to manage invasive species vectors: (1) that vessel owners and operators hold a current Clean Vessel Pass for their vessel; (2) that the vessel meets clean vessel standards including hull biofouling, gear biofouling and residual seawater requirements; and (3) that owners and operators maintain and can present records on the steps taken to meet the clean vessel standards. The plan was made operative in 2017, and to date, uptake has generally been positive with only a small number of compliance issues. The adoption of this plan is largely due to an integrated iwi, community and agency management approach which has encouraged engagement and participation from the Fiordland stakeholders. The ongoing success of this programme will rely on the commitment from the partnering central and local government agencies to improve and refine the plan, and on a general elevation in the importance of marine biosecurity management nationwide. Ideally, the plan will significantly reduce the risk of further marine bioinvasions within the FMA.
... Regarding aquaculture farms, the highest number of NIS in the Prima Fish farm may be due to its proximity to the Monastir fishing port which is also the base harbor for the boats of this farm. In this regard, fouling NIS associated with aquaculture equipment such as ropes and buoys could be transported offshore from the fishing port (Campbell et al., 2017). Therefore, the aquaculture farms of Monastir Bay may be acting as stepping-stones for the spread of NIS from Monastir to nearby natural areas, such as the SCA of the Kuriat Islands (Mesel et al., 2015;Chebaane et al., 2019). ...
The Mediterranean Sea is a marine biodiversity hotspot under threat. One of the major impacts on its biological resources and services comes from the invasiveness of non-indigenous species (NIS). Nevertheless, NIS monitoring programs in the south basin of the Mediterranean Sea are in an early implementation stage. This study aims to describe NIS and cryptogenic species distribution in Monastir Bay (Tunisia) and to identify risk areas for the introduction and spread of invasive species, providing a baseline for future monitoring programs. To this end, a series of Rapid Assessment Surveys were carried out to identify NIS and cryptogenic species in one marina, five fishing ports, two aquaculture farms and the Special Conservation Area of the Kuriat islands. 24 species were found, of which 11 constitute new records for Monastir Bay, which represent a 33.3% of the total NIS reported in this Bay. Assemblages differed between substrata types, being NIS more abundant in artificial than in natural substrata. Regarding locations, Cap Monastir Marina was the most invaded site, the most transited by vessels and the only one visited by international sailing. Hence, this marina constitutes the main risk area to be monitored, although the fishing ports and fishing farms in the semi-enclosed coastal lagoon of Monastir Bay can also be considered as risk areas. Nevertheless, more research effort is needed in Monastir Bay in order to update the records of NIS and cryptogenic species and increase insight on the ecological evolution of these species and their related impacts on natural communities and marine resources.
... The high diversity recorded in this study also indicates that finfish farms are able to support the recruitment of a wide range of taxa. While this supports recruitment and expansion of local benthic communities, farms may also act as stepping stones for the spreading of non-indigenous species, thus potentially resulting in negative impacts on local communities (Grigorakis and Rigos 2011;Fernandez-Gonzalez and Sanchez-Jerez 2014;Campbell et al. 2017). ...
Biofouling is one of the challenges that can strongly affect the finfish farm economy. Although several studies on biofouling in aquaculture have been conducted in the Mediterranean Sea, they focused on specific taxa or were limited to a particular period of sampling. The present study investigated for the first time the development, composition and variation in a biofouling community in a finfish farm with immersion time, season and depth. The results indicate that all these factors influence biofouling succession and recruitment. Moreover, the species that had a crucial role in structuring the community and in the farm cleaning activities were the ascidian Styela plicata and the bivalve Mytilus galloprovincialis. Compared with the literature data, the results highlight the heterogeneity in the composition of the biofouling present in the Mediterranean Sea. Moreover, such knowledge of the biofouling community could provide important information about management efforts and the costs that farmers will face when siting new fish farms.
Microplastics are tiny plastic particles that we humans produce, and they are constantly moving around our planet. They have become a very serious concern to the environment, because we produce them in huge quantities, and they are very slow to degrade. When microplastics reach freshwater environments, they can pollute drinking water, affect all kinds of life forms, and find their way to our diet. Many international organizations are trying to reduce the use and production of articles like bags, clothes, hygiene products and even toys, that are made of or contain microplastics. Researchers all over the world are looking into ways to degrade microplastics, and to discover new, eco-friendly materials. But there are many things we all can do to help as well. All of us can make a difference to reduce microplastics pollution. Palavras-chave: Environmental impact, freshwater pollution, human activities, microplastics. RESUMO Os microplásticos são pequenas partículas de plástico produzidas pelos humanos e que estão em constante movimento pelo nosso planeta. Eles se tornaram uma preocupação muito séria para o meio ambiente, porque nós os produzimos em grandes quantidades e eles são muito lentos para se degradar. Quando os microplásticos atingem ambientes de água doce, eles podem poluir a água potável, afetar todos os tipos de formas de vida e encontrar o caminho para nossa dieta. Muitas organizações internacionais estão tentando reduzir o uso e a produção de artigos como bolsas, roupas, produtos de higiene e até brinquedos, que são feitos ou contêm microplásticos. Pesquisadores de todo o mundo estão procurando maneiras de degradar microplásticos e descobrir novos materiais ecologicamente corretos. Mas há muitas coisas que todos nós podemos fazer para ajudar também. Todos nós podemos fazer a diferença para reduzir a poluição por microplásticos. Palavras-chave: Impacto ambiental, poluição da água doce, atividades humanas, microplásticos.
Norway has the second longest coastline in the world, and it is challenging to monitor non-indigenous marine species (NIMS) along the entire shore including the Norwegian areas in the Barents Sea and along Svalbard. There is currently no national program for such monitoring, however some activity is taking place on specific species and organism groups which is presented here.
Historically transport of NIMS is ballast water have been the main pathway into the Norwegian coast, but with the implementation of the Ballast Water Convention this risk is minimized. Biofouling on vessels coming into the Norwegian coast is thus considered to be the most important vector for marine introduction of new species. An analysis of the frequency and origin (last port call) for 158 000 vessel arrivals into Norwegian ports in the period 2020-2021 is presented. The results show that the Oslofjord area and the west coast is the areas with highest risk for marine introductions by vessels. Other vectors for such introductions into Norway are evaluated like the increasing amount of floating debris which can carry fouling organisms, larvae and eggs to new areas. An analysis of historical data for the established NIMS in Norway show that the southern area of Norway is most susceptible to new species. This pattern is not only dependent on the vector pressure but also reflects the temperature gradient northwards along the coast.
Measures for prevention of new species to arrive and management of problematic species is also discussed.
Marine litter colonization by marine invertebrate species is a major global concern resulting in the dispersal of potentially invasive species has been widely reported. However, there are still several methodological challenges and uncertainties in this field of research. In this review, literature related to field studies on marine litter colonization was compiled and analyzed. A general overview of the current knowledge is presented. Major challenges and knowledge gaps were also identified, specifically concerning: 1) uncertainties in species identification, 2) lack of standardized sampling methodologies, 3) inconsistencies with the data reported, and 4) insufficient chemical-analytical approaches to understand this phenomenon. Aiming to serve as a guide for future studies, several recommendations are provided for each point, particularly considering the inaccessibility to advanced techniques and laboratories.
Globally, there is growing concern regarding the effects of the increasing anthropogenic pressures in marine communities. Artificial structures such as marinas and aquaculture facilities serve as invasion hotspots; hence, monitoring fouling communities on these structures can be valuable for detecting new invasions. In the current study, 24 settlement PVC plates were deployed for three months to compare the recruitment ability of these two artificial environments along the south coast of the offshore island of Madeira (NE Atlantic). The results showed higher variations in the species richness between regions (SW vs. SE) than between artificial habitats (sea-cages vs. marinas), although the community composition differed. Cnidaria and Bryozoa were the most representative groups in the aquaculture systems, while Bryozoa and Chordata were in the marinas. A sum of 18 NIS was recorded for the study, accounting for between 21.88% and 54.84% of the total number of species in the aquaculture facilities and marinas, respectively. The higher NIS percentage from the marinas was even more explicit in the SE coast, where Cradoscrupocellaria bertholletii, Parasmittina alba, and Botrylloides niger distinctly dominated fouling populations. The results suggest that at least some particular NIS previously reported in the studied marinas successfully colonized sea-cages. Future assessments need to address the potential role of aquaculture facilities as drivers for the secondary spread of NIS. Additionally, two new records are considered for Madeira: Eudendrium capillare and Ericthonius punctatus.
Plastic debris constitutes up to 87% of marine litter and represents one of the most frequently studied vectors for marine alien species with invasive potential in the last 15 years. This review addresses an integrated analysis of the different factors involved in the impact of plastic as a vector for the dispersal of marine species. The sources of entry of plastic materials into the ocean are identified as well as how they move between different habitats affecting each trophic level and producing hot spots of plastic accumulation in the ocean. The characterization of plastic as a dispersal vector for marine species has provided information about the inherent properties of plastics which have led to its impact on the ocean: persistence, buoyancy, and variety in terms of chemical composition, all of which facilitate colonization by macro and microscopic species along with its dispersion throughout different oceans and ecosystems. The study of the differences in the biocolonization of plastic debris according to its chemical composition provided fundamental information regarding the invasion process mediated by plastic, and highlighted gaps of knowledge about this process. A wide range of species attached to plastic materials has been documented and the most recurrent phyla found on plastic have been identified from potentially invasive macrofauna to toxic microorganisms, which are capable of causing great damage in places far away from their origin. Plastic seems to be more efficient than the natural oceanic rafts carrying taxa such as Arthropoda, Annelida, and Mollusca. Although the differential colonization of different plastic polymers is not clear, the chemical composition might determine the community of microorganisms, where we can find both pathogens and virulent and antibiotic resistance genes. The properties of plastic allow it to be widely dispersed in practically all ocean compartments, making this material an effective means of transport for many species that could become invasive.
Microplastics (MPs) are widely distributed and extensively found within marine ecosystems, and approximately 8 million tons of plastics are being dumped into the sea annually. Once reached the marine environment, plastics tend to get fragmented into smaller particles through photo-degradation, mechanical and biological processes.
These MPs have raised concerns globally due to their potential toxic impacts on a wide variety of aquatic fauna and humans. Ingested microplastics can cause severe health implications in fishes, including reduced feeding intensity, improper gill functioning, immunosuppression, and compromised reproducibility. Several studies were
also conducted to scrutinize MPs trophic transfer through the food chain from primary producers to top predators and their bioaccumulation. This paper briefly summarizes all the possible sources, routes, bioavailability, trophic transfer, and consequences of microplastics in fishes. The review article also intended to highlight various
mitigation strategies like implementing Four R's concept (refuse, reduce, reuse, and recycle), integrated strategies, ban on single-use plastics, use bioplastics, and create behavioural changes with public awareness.
Reduced competition is a frequent explanation for the success of many introduced species. In benthic
marine biofouling communities, space limitation leads to high rates of overgrowth competition. Some
species can utilise other living organisms as substrate (epibiosis), proffering a competitive advantage
for the epibiont. Additionally, some species can prevent or reduce epibiotic settlement on their surfaces
and avoid being basibionts. To test whether epibiotic pressure differs between native and introduced
species, we undertook ex situ experiments comparing bryozoan larval settlement to determine if
introduced species demonstrate a greater propensity to settle as epibionts, and a reduced propensity
to be basibionts, than native species. Here we report that introduced species opportunistically settle on
any space (bare, native, or introduced), whereas native species exhibit a strong tendency to settle on
and near other natives, but avoid settling on or near introduced basibionts. In addition, larvae of native
species experience greater larval wastage (mortality) than introduced species, both in the presence and
absence of living substrates. Introduced species’ ability to settle on natives as epibionts, and in turn
avoid epibiosis as basibionts, combined with significantly enhanced native larval wastage, provides a
comprehensive suite of competitive advantages contributing to the invasion success of these biofouling
species.
Marine plastic pollution has been a growing concern for decades. Single-use plastics (plastic bags and microbeads) are a significant source of this pollution. Although research outlining environmental, social, and economic impacts of marine plastic pollution is growing, few studies have examined policy and legislative tools to reduce plastic pollution, particularly single-use plastics (plastic bags and microbeads). This paper reviews current international market-based strategies and policies to reduce plastic bags and microbeads. While policies to reduce microbeads began in 2014, interventions for plastic bags began much earlier in 1991. However, few studies have documented or measured the effectiveness of these reduction strategies. Recommendations to further reduce single-use plastic marine pollution include: (i) research to evaluate effectiveness of bans and levies to ensure policies are having positive impacts on marine environments; and (ii) education and outreach to reduce consumption of plastic bags and microbeads at source.
A rising number of valuable uses being found for seaweed -- from food and fertilizer to pharmaceuticals and industrial gels -- is driving the rapid growth of an industry that could easily and needlessly drop into some of the same pitfalls previously experienced in both agriculture and fish farming. Drawing on the expertise of 21 institutions worldwide, UN University's Canadian-based Institute for Water, Environment and Health, and the Scottish Association for Marine Science, a UNU associate institute, today published policy advice to the burgeoning, multi-billion dollar industry to help it avoid expensive mistakes and pursue best practices, backed by relevant case studies involving crops like bananas and shrimp. The authors note that seaweed farms now produce more than 25 million metric tonnes annually. The global value of the crop, US$6.4 billion (2014), exceeds that of the world's lemons and limes. Seaweed farming has grown from the late 1950s into an industry offering sustainable employment in developing and emerging economies, notably China (which produces over half of the global total of seaweed -- 12.8 million tonnes) and Indonesia (27% of global production -- 6.5 million tonnes). Other major producers include the Republic of Korea and the Philippines.The experts note that increasing demands being placed on the marine environment and competition for maritime space (renewable energy, aquaculture, fisheries, et cetera) necessitates coordination and co-operation between different users, an ecosystem-wide management approach and marine spatial planning (MSP) for aquaculture, alongside regulation to protect the wider marine environment.
In a nutshell, the key points for the seaweed industry come down to: Biosecurity -- preventing the introduction of disease and non-indigenous pests and pathogens;Investing in risk assessment and early disease detection;Building know-how and capacity within the sector;Cooperative planning to anticipate and resolve conflicts between competing interests in finite coastal marine resources, and Establishing management policies and institutions at both national and international levels.
Microplastics are persistent environmental contaminants found in marine environments worldwide. Microplastic particles isolated from coastlines in the Canterbury region of New Zealand were quantified and characterised. Sediment samples were collected from ten locations representing exposed-beach, estuarine and harbour environments in both urban and non-urban settings. Particles were isolated from sediments using a NaCl density-separation procedure and quantified and characterised with a combination of optical/fluorescence imaging and micro-Raman spectroscopy. Microplastics were detected at 8 out of 10 locations, at concentrations ranging from 0 – 45.4 particles kg-1 of dry sediment. The majority of microplastics were identified as polystyrene (55%), polyethylene (21%) and polypropylene (11%). Microplastic concentrations in exposed-beach environments were significantly greater than harbour and estuarine environments.
Marine wildlife faces a growing number of threats across the globe, and the survival of many species and populations will be dependent on conservation action. One threat in particular that has emerged over the last 4 decades is the pollution of oceanic and coastal habitats with
plastic debris. The increased occurrence of plastics in marine ecosystems mirrors the increased prevalence of plastics in society, and reflects the high durability and persistence of plastics in the
environment. In an effort to guide future research and assist mitigation approaches to marine conservation, we have generated a list of 16 priority research questions based on the expert opinions
of 26 researchers from around the world, whose research expertise spans several disciplines, and covers each of the world’s oceans and the taxa most at risk from plastic pollution. This paper highlights
a growing concern related to threats posed to marine wildlife from microplastics and fragmented debris, the need for data at scales relevant to management, and the urgent need to develop interdisciplinary research and management partnerships to limit the release of plastics into the environment and curb the future impacts of plastic pollution.
Shellfish aquaculture is often positioned as an adaptive alternative to traditional resource industries, but the social and cultural effects of expanding production on coastal/marine social-ecological systems are unclear. Reporting on a multimethods study, we present perceptions about shellfish aquaculture collected through interviews, participant-employed photography, and a household survey in British Columbia, Canada. With an approach focused on local preferences for social-ecological conditions and the ways in which those conditions may be enhanced or diminished, we indicate that perceptions of the effects of aquaculture on the environment, economy, and lived experience are composed of both objective and subjective components. Interview responses and survey opinions varied widely and included bimodal responses. Industry interviewees tended to focus on environmental and economic benefits while acknowledging concerns about the environment and lived experience. Non industry interviewees typically questioned the environmental effects while underscoring economic benefits and negative effects on experience. Most survey participants felt positively about the effects on the economy, expressed negativity and uncertainty about effects on the environment, and demonstrated the greatest variability in opinions about effects on lived experience. Findings revealed uncertainty and alienation across all dimensions. Our findings, used as an analytical lens, support the usefulness of the concept of well-being in attempts like this one to understand the dynamics of coastal communities by providing a framework for deciphering what is important to individuals and societies experiencing change and considering adaptations.
In the southwestern Atlantic Ocean, Isognomon bicolor is an invasive bivalve on rocky shores along the coast of Brazil. We report here records of this species rafting on floating debris in Uruguay (ca. 34° S). Rafting may be an important mechanism for the dispersal of I. bicolor on the coast of Uruguay and elsewhere in the Southernmost Atlantic Ocean and the presence of this invasive species on rocky shores should be monitored.
Following prolonged westerly gales impacting the south and west coasts of the British Isles in Winter 2013-14 unusually large numbers of rafting organisms have been reported. Six species of bivalve and one gastropod with their normal ranges in the Caribbean and SE coasts of the USA were found attached to plastic macro-litter washed ashore on the south coast of England and west coast of Ireland. Pinctada imbricata (Roding, 1798) (Atlantic Pearl Oyster) was recorded once before in 1988 as P. radiata but is here regarded as the western Atlantic subspecies. Isognomon bicolor (CB Adams, 1845) (Bicolor purse oyster), Pododesmus rudis (Broderip, 1834) (Atlantic false jingle), Aequipecten heliacus (Dall, 1925), Euvola ziczac (Linnaeus, 1758) (Zigzag Scallop) and Chama cf. congregata Conrad, 1833 (Little Corrugate Jewelbox) are herein reported for the first time from the eastern Atlantic. Should sea temperature rises continue such long distance rafting could be a mechanism for the establishment of alien western Atlantic species in the NE Atlantic.
The Suez Canal is one of the most important waterways in the world – during the last year 17,148 ships passed through the Canal – reducing emissions, saving time, and operating costs to shippers. The rapid increase in ship size from the " Post-Suezmax " (> 12,000 TEU) to the latest container vessels (> 19,000 TEU) now requires enlargements of port facilities and canals. A project of this magnitude, and with potentially negative environmental outcomes , requires a transparent and scientifically sound " Environmental Impact Assessment " (EIA). An explicit obligation on Parties to the Convention on Biological Diversity (https://www.cbd.int/doc/ legal/cbd-en.pdf) was made to consider transboundary impacts on biodiversity, particularly those associated with invasive non-indigenous species. Although a non-binding instrument, the " Rio Declaration on Environment and Development " sets forth important principles of international environmental law (UN 1992): States are responsible for ensuring that activities within their jurisdiction do not damage the environment of other States, and EIA, as a national instrument, shall be undertaken for proposed activities that are likely to have a significant adverse impact on the environment. To our knowledge, no Environmental Impact Assessment has been fig. 1. The number of nonindigenous species in some Mediterranean countries. In red, the fraction of species likely introduced through the Suez Canal.
Assessment of the ecological and economic/societal impacts of the introduction of non-indigenous species (NIS) is one of the primary focus areas of bioinvasion science in terrestrial and aquatic environments, and is considered essential to management. A classification system of NIS, based on the magnitude of their environmental impacts, was recently proposed to assist management. Here, we consider the potential application of this classification scheme to the marine environment, and offer a complementary framework focussing on value sets in order to explicitly address marine management concerns. Since existing data on marine NIS impacts are scarce and successful marine removals are rare, we propose that management of marine NIS adopt a precautionary approach, which not only would emphasise preventing new incursions through pre-border and at-border controls but also should influence the categorisation of impacts. The study of marine invasion impacts requires urgent attention and significant investment, since we lack the luxury of waiting for the knowledge base to be acquired before the window of opportunity closes for feasible management.
Marine wildlife faces a growing number of threats across the globe, and the survival of many species and populations will be dependent on conservation action. One threat in particular that has emerged over the last 4 decades is the pollution of oceanic and coastal habitats with plastic debris. The increased occurrence of plastics in marine ecosystems mirrors the increased prevalence of plastics in society, and reflects the high durability and persistence of plastics in the environment. In an effort to guide future research and assist mitigation approaches to marine conservation, we have generated a list of 16 priority research questions based on the expert opinions of 26 researchers from around the world, whose research expertise spans several disciplines, and covers each of the world’s oceans and the taxa most at risk from plastic pollution. This paper highlights a growing concern related to threats posed to marine wildlife from microplastics and fragmented debris, the need for data at scales relevant to management, and the urgent need to develop interdisciplinary research and management partnerships to limit the release of plastics into the environment and curb the future impacts of plastic pollution.
The distinctive Mediterranean-Atlantic fanworm polychaete, Sabella spallanzanii (Gmelin, 1791), is recorded from New Zealand, in both North and South Island, consequent upon its discovery first in the port area of Lyttelton in Lyttelton Harbour and later 800 km further north in the port area of Auckland in Waitemata Harbour. Morphology distinguishing the species from other sabellids is highlighted. In the initial occurrence in March 2008 one large specimen was identified from samples taken by a surveillance team off subtidal wharf structures in Lyttelton port. In July and August 2008 further large specimens were found both nearby and dispersed across the inner port area, with reproductive maturity appearing imminent in some. The New Zealand Government funded repeated search and culling by divers, directed towards possible local elimination, with over 380 specimens removed from Lyttelton by December 2009. However, in August 2009 a single large specimen was found in an enclosed port area in Waitemata Harbour, then several more, and in October 2009 numerous specimens were found on a barge hull berthed there. Also it became apparent that a second generation of colonisers was present in both harbours. By early 2010 well-grown specimens had been found in disparate Waitemata Harbour locations over a large area. The decision to suspend culls was made in February 2010, and elimination efforts were abandoned in June 2010, two years after first detection. The arrival and apparent establishment of S. spallanzanii in New Zealand is ascribed to accidental international transfer probably in 2007, either via hull fouling or ballast water, but it is not known if the two ports were colonised via the same transiting vessel.
With globalization, agriculture and aquaculture activities are increasingly affected by diseases that are spread through movement of crops and stock. Such movements are also associated with the introduction of non‐native species via hitchhiking individual organisms. The oyster industry, one of the most important forms of marine aquaculture, embodies these issues. In Europe disease outbreaks affecting cultivated populations of the naturalized oyster Crassostrea gigas caused a major disruption of production in the late 1960s and early 1970s. Mitigation procedures involved massive imports of stock from the species’ native range in the northwestern Pacific from 1971 to 1977. We assessed the role stock imports played in the introduction of non‐native marine species (including pathogens) from the northwestern Pacific to Europe through a methodological and critical appraisal of record data. The discovery rate of non‐native species (a proxy for the introduction rate) from 1966 to 2012 suggests a continuous vector activity over the entire period. Disease outbreaks that have been affecting oyster production since 2008 may be a result of imports from the northwestern Pacific, and such imports are again being considered as an answer to the crisis. Although successful as a remedy in the short and medium terms, such translocations may bring new diseases that may trigger yet more imports (self‐reinforcing or positive feedback loop) and lead to the introduction of more hitchhikers. Although there is a legal framework to prevent or reduce these introductions, existing procedures should be improved.
Ciclo de Retroalimentación Positiva entre la Introducción de Especies Marinas No‐Nativas y el Cultivo de Ostras en Europa
Pearl oyster aquaculture is a major activity in French Polynesia atoll lagoons. After the economic decline that characterized the last decade, concerns recently rose about discarded installations and materials that supported aquaculture practices and by facilities abandoned after they had to close their activities. In May 2013, a first inventory of the type and amount of pearl farms derelict gear (PFDG) was achieved on 47 sites in Ahe lagoon. Surveys were conducted within and outside the boundaries of aquaculture concessions. Twenty types of PFDG littered the lagoon floor and the water column. The most impacted areas were near abandoned grafting houses with up to nine types of PFDG. Forty-five percent of the sites were impacted, including outside concessions. While management authorities are fully aware of the problem, this first assessment is a wake-up call to stimulate the cleaning of lagoons, enhance awareness among farmers, and identify potential ecological consequences on lagoon ecosystems.
Plastic and other anthropogenic debris (e.g., rubber, tar) augment natural floating substrates (e.g., algal rafts, pumice) in the open ocean, allowing "islands" of substrate-associated organisms to persist in an otherwise unsuitable habitat. We examined a total of 242 debris objects collected in the eastern Pacific in 2009 and 2011 (32-39A degrees N, 130-142A degrees W) and the western Pacific in 2012 (19-41A degrees N, 143-156A degrees E). Here, we ask: (a) What taxa are associated with plastic rafts in the North Pacific? and (b) Does the number of taxa associated with plastic debris vary with the size of the debris "island?" We documented 95 rafting taxa from 11 phyla. We identified several potentially invasive plastic-associated rafting taxa, including the coral pathogen Halofolliculina spp. In concordance with classic species-area curves, the number of rafting taxa was positively correlated with the size of the raft. Our findings suggest that diversity patterns on plastic debris are compatible with the concept of island biogeography.
This is the first report about the arrival of the encrusting cheilostomatid bryozoan Watersipora subtorquata on floating seaweeds in German coastal waters of the North Sea. During summer 2012, drifting or stranded thalli of the non-indigenous brown macroalga Himanthalia elongata were investigated on the island of Helgoland showing numerous benthic species covering the holdfast of Himanthalia. Out of the 120 basal structures investigated, 8.3% had viable colonies of the invasive, non-native W. subtorquata attached to them. Himanthalia and W. subtorquata have both their nearest origin reported to be in the English Channel (La Manche), approximately 800 km away from Helgoland. Now we found W. subtorquata as a rafting species in the eastern part of the North Sea, showing its ability to distribute easily over very large distances using floating algae as a natural transport vector. This event might constitute the first step in the potential introduction of this alien species into German coastal waters.
We developed two risk models to investigate the movement of introduced marine species into High-value areas (HVAs), using Undaria pinnatifida invasions in New Zealand as a model system. This process focussed on the secondary transfer of Undaria into the HVAs, as it is already introduced to New Zealand. The first model was a qualitative, theoretical risk assessment based on expert opinion, and was used by management to re-assess the potential impacts of Undaria on values associated with a set of six, expert identified, HVAs. The risk re-assessment process identified that Undaria posed an extreme risk to a majority of values in all evaluated HVAs. Based on this outcome, a realised risk assessment model was developed and is described that uses quantitative vessel and propagule strength data to examine secondary transfers of Undaria into HVAs. The realised risk assessment is the next stage in the process of delineating the risk Undaria poses to New Zealand HVAs. The intent of this process was to provide salient, credible and legitimate information to decision-makers in a transparent manner because direct impact data is limited and uncertain. Both models presented are readily applicable to Undaria invasions in different regions and countries, with the original re-assessment model having been used by biosecurity managers.
Globally our awareness of both the pervasiveness and magnitude of marine litter and the associated
environmental and social problems is growing (Ribic et al. 1992, ANZECC 1996a, GESAMP 2001,
Kiessling 2003, Cho 2005, UNEP 2005, OSPAR 2006, HELCOM 2007). This growth in knowledge is
being paralleled by a concomitant increase in the number and scope of national and international
marine litter investigations and assessment programmes. The objectives underpinning these litter
assessment programmes are quite diverse with groups/organizations variously targeting increased
public awareness, better understanding of the risks and impacts of litter, more understanding of litter
sources and sinks to support improved management and not the least, cleaner waterways and
beaches at local, regional, national and international scales. This variety in the purpose of assessment
programmes is matched by the diversity in the operational structure of those programmes.
Regardless of the underpinning motivation, marine litter investigations will generally fall into one of
three basic types:
1) Beach litter surveys.
2) Benthic litter surveys, which include:
a) Observations made by divers, submersibles or camera tows.
b) Collection of litter via benthic trawls.
3) Floating litter surveys, which include:
a) Observations made from ship or aerial based platforms.
b) Collection of litter via surface trawls.
Ultimately, to effectively manage and thereby mitigate the impacts from marine litter, there is a need to
develop a good understanding of the problems and specifically to increase our knowledge about the
principle types and sources of litter and the behaviours that result in litter entering the marine
environment. To achieve this aim, there is a need to ensure that good quality data are available that
will allow comprehensive analyses of the nature and sources of litter in marine environments and how
these vary through time and in response to management interventions.
In spite of growing interest and a mounting body of evidence from research and surveys, it is widely
accepted that a major factor that limits our knowledge of (and therefore the ability to manage) marine
litter results from inconsistencies in the design and delivery of sampling and assessment programmes.
These inconsistencies largely result from a lack of consistent objectives and litter classification
systems between alternative monitoring programmes (Ribic et al. 1992, ANZECC 1996a, Cheshire
and Westphalen 2007).
There is a growing need to develop standardized operational guidelines for marine litter survey and
monitoring programmes so that litter levels on our beaches and within our seas and oceans can be
estimated and interpreted through long-term, broad scale comparative studies that will support
management at both national and international scales. Similarly, given that marine litter management
ultimately relates to social and behavioural changes, there is a need to develop or maintain public
awareness and education through simpler, less rigidly structured, programmes.
Objectives
The objectives for this study were to develop a set of standardized operational guidelines for the
conduct of beach, benthic and floating litter assessments. In working to achieve this outcome it
became clear that there was also a need to address the different underlying purposes, particularly in
relation to beach litter assessments, and to that end we have developed two classes of surveys:
1) Comprehensive surveys for beach, benthic and floating marine litter
These protocols are targeted at the collection of highly resolved data to support the
development and/or evaluation of mitigation strategies in coastal and marine systems. The
protocol for these surveys includes a highly structured framework for observations at
regional, national and international scales.
EXECUTIVE OVERVIEW
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2) Rapid surveys for beach litter
This protocol comprises a simplified version of the comprehensive beach survey, targeted
primarily at developing public awareness and education about marine litter issues and is thus
not constrained by the need to fit within a broader spatio-temporal comparison framework.
Such surveys may be used as a vehicle for broader based community engagement and in
building community capacity when working towards inclusion within the comprehensive
survey framework.
In developing the guidelines marine litter was defined as any waste, discarded or lost material,
resulting from human activities, that has made it into the marine environment, including material found
on beaches or material that is floating or has sunk at sea. Some organic materials (e.g. faeces or food
waste) have been explicitly excluded and we do not include naturally sourced materials such as
vegetation (e.g. seagrass wrack, algae or river sourced trees and branches). Organic materials have
only been included where they have been through some form of processing (e.g. cloth and processed
timber).
Scope of this report
As noted by the United Nations General Assembly Resolution (A/60L.22), one of the most significant
barriers to addressing the global problem of marine litter is the absence of information that can be
used to determine the sources, the movement and paths, the oceanographic dynamics, the trend and
the more general status of marine litter. This kind of information is basic and mandatory in order to
assess the impact of marine litter on national, regional and global scales. The absence of harmonized
and globally agreed upon scientific methodologies to monitor changes in accumulation rates and the
composition of litter, and the effectiveness of management arrangements over time are critical issues
that require the development of appropriate guidelines.
In order to address this problem the Regional Seas Programme (RSP) of UNEP, together with the IOC
of UNESCO, and with the support of the Government of Australia, within the context of the ‘Global
initiative on marine litter’ initiated the work on developing guidelines for the ‘standardization’ and
harmonization of the survey and monitoring of marine litter worldwide. Such guidelines will contribute
to the global efforts, especially of developing countries, to address and abate marine litter and will
assist scientists, governmental authorities and policy makers and respective efforts by governments,
NGOs, Regional Seas Programmes and other relevant organizations to address the problem of the
monitoring and assessment of marine litter.
Within the framework of the collaboration between IOC and UNEP, related to the development of the
‘UNEP/IOC Guidelines on Survey and Monitoring of Marine Litter’, this report aims to outline practical
operational guidelines for the survey and monitoring of marine litter and in particular:
1) To collect information from around the world on existing experience and methods for the
monitoring and assessment of marine litter drawing on information already compiled by
UNEP, OSPAR, HELCOM, the Australian Department of the Environment and Water
Resources, the Ocean Conservancy’s NMDMP and other relevant sources.
2) To develop a comparative analysis of selected methodologies for marine litter survey and
monitoring, including reporting protocols and forms.
3) To develop a set of practical operational guidelines on survey and monitoring of on-shore,
floating and sea-floor marine litter for consistent application worldwide. These guidelines
include advice on the format and organization of data needed to support statistical and
trend based analyses.
The survey design, guidance and data recording protocols are intended to support comprehensive
surveys and monitoring as well as rapid surveys suitable for application by community-based or other
non-research trained personnel.
Given the extensive logistical requirements for surveys of floating and benthic litter, it is not practical to
develop rapid assessment surveys for either floating or benthic litter. It is recognized however, that
community groups may well participate in ad-hoc clean-up and removal operations for floating or
benthic litter which may then be reported in general terms (e.g. total volume or weight of material
collected).
EXECUTIVE OVERVIEW
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Similarly, while there is broad agreement about the importance of microplastics (a component of
neustonic litter) as a threat to wildlife (Derraik 2002, Lattin et al. 2004), investigations into this type of
litter are technically demanding and require specialist equipment and training (see Lattin et al. 2004);
specific survey guidelines for this form of litter have not been included.
Approach used in developing guidelines
In order to organize the preparation of the Guidelines, the RSP of UNEP and the IOC of UNESCO,
with the support of the Government of Australia, established an international Technical Working Group
(TWG) comprising of sixteen “globally spread” experts from various regions and countries of the world.
The TWG began work in July 2007 with support from UNEP and IOC; Prof. Anthony Cheshire from
Australia took the lead role in the project and acted as a Chief Scientist, Team Leader and Coordinator
of the TWG.
The TWG undertook a detailed review of 13 different sampling protocols that are currently being used
around the world to survey beach cast, benthic and/or floating marine litter. Survey protocols were
assessed against 46 criteria related to the basic structure of the survey, the analysis of sampling units,
the frequency and timing of surveys, the systems used for litter classification and the underpinning
framework for facilitation and management of logistics.
Results of this review were summarised and then used to determine the best way to structure different
types of litter surveys. The outcomes from this work have been incorporated into the development of
these Operational Guidelines. In framing these recommendations a set of draft guidelines were
reviewed by all members of the TWG and these were further developed during a workshop held in
Phuket, Thailand during May 2008. Following this workshop the results were compiled into an agreed
set of operational guidelines to support the delivery of marine litter surveys.
In total four sets of guidelines have been developed, one for each of:
1) Comprehensive assessments of beach cast litter;
2) Assessments of benthic litter;
3) Assessments of floating litter; and
4) Rapid assessments of beach cast litter.
Chapter I presents an introduction to marine litter and the associated problems. General information
about the application of these guidelines in a global / regional framework is detailed in Chapter II while
the detailed methodology for each of the guidelines is presented in Chapters III-VI. Appendix A lists
the TWG membership while Appendix B provides a summary of the findings from the review of the
various litter assessment programmes that formed the background to these guidelines.
Predominant features of barotropic and baroclinic circulation and mixing in the Hauraki Gulf on New Zealand's north‐east coast are described using measurements and 3‐dimensional numerical model simulations. Circulation in the Hauraki Gulf is strongly 3‐dimensional with a primary dynamical balance between surface wind stress and the associated pressure gradients against the land. This leads to persistent up/downwelling and surface manifestations in sea surface temperature patterns which are shown to vary systematically and markedly with wind direction and stratification intensity. A high degree of correspondence between a baroclinic numerical model and measured temperature and nitrate concentrations indicated that many of the observed spatial patterns could be largely explained by the interaction of the wind and tidal circulation with the unique morphology of the Gulf. After strong southeasterly winds, local responses operated in conjunction with the regional “capping” mechanism described by Sharpies (1997) of downwind surface water intrusion from the shelf into the Gulf. However, the morphology acts to enhance local upwelling causing bottom waters to be injected into the surface layers which disrupts the “cap”. The headlands and islands play an additional vertical mixing role by presenting bathymetric variability leading to the formation of upwelling jets in the core of eddies forming during ebb and flood tides. By introducing bottom waters into the upper water column and acting to over‐turn the water body, up/downwelling is an important mechanism for mixing and biological productivity which could vary systematically within the Gulf in response to seasonal and interannual variability in the upwelling patterns. Persistent south‐east winds above a threshold of 10–12 m s were found to initiate breakdown of seasonal temperature stratification in the Gulf, with complete breakdown after 3 days during a cyclone with 8–23 m s winds. Vertical eddy diffusivity increased from 0.0015 to 0.04 m s as the cyclone strengthened.
Marine litter has been defined as solid materials of human origin discarded at sea, or reaching the sea through waterways. The effect of marine debris on wildlife, tourism and human health is well documented and there is considerable scientific literature about plastic litter in the sea and over the seabed, mostly highlighting the possible impact on marine mammals and tourism. Dispersal of marine and terrestrial organisms on floating objects has biogeographical and ecological interest. For some species, extension of their geographical range is more likely to be related to transport of mature individuals on floating rafts than to the active or passive dispersal of reproductive propagules. Variability and variety of rafting materials has increased dramatically in recent years and marine litter has been used widely as a raft by ‘hitch-hiking’ species. This paper reports on the benthic invertebrates living on marine debris transported by wind and surface currents over the western Mediterranean Sea. Plastics accounted for the major item of debris because of poor degradability, however glass, cans, fishing nets and polyurethane containers, were also found. Macro-benthos living on raft material comprised mainly molluscs, polychaetes and bryozoans. Large fish were found commonly below large plastic bags. Estimations of the distances that may be covered by hitch-hiking species and the contribution of rafting to the theoretical dispersal of species is provided.
Bivalve reefs are vital ecosystem engineers but have declined or disappeared in many regions. In the Firth of Thames (FOT), north-east New Zealand, overfishing, sedimentation or both led to the virtual extinction of extensive reefs of green-lipped mussels (Perna canaliculus). The mussel reefs have not recovered since commercial fishing ceased in 1968, possibly because the muddy sediments that replaced the reefs are an unsuitable habitat for adult mussels. To test this hypothesis, we transplanted mussels into cages on the seafloor for 500 days at three sites along a turbidity gradient (average visibility 0.8–4.7 m) within the mussel reefs’ former range for 500 days. Results showed that 68% of individuals survived the experiment and grew an average of 19 mm in length. Survivorship and growth did not differ between sites. However, at the completion of the experiment, mussels from the least turbid site were in better condition (condition index = 15) than those from the most turbid site (condition index = 10). Our results suggest that the current lack of recovery of mussel reefs in the FOT is attributable to low recruitment and survivorship of juvenile mussels. Restoration of mussel reefs and the ecosystem services that they provide may therefore be possible.
Bivalves have been grown and transported for culture for hundreds of years and the introduction of some species outside of their native range for aquaculture has been suggested to be one of the greatest modes of introduction of exotic marine species. However, there has yet to be a thorough assessment of the importance of aquaculture and bivalve culture in particular, to the introduction and spread of exotic species. This paper reviews some of the environmental and ecological implications of the relationship between bivalve aquaculture and the introduction and spread of exotic species, management implications and mitigation strategies. Two broad classes of introductions of exotic species may result from activities associated with bivalve aquaculture. First, the intentional introduction of exotic species into an area for aquaculture purposes, i.e. the "target" species. These are typically foundation or engineering species and may have a considerable influence on receiving ecosystems. Second, the introduction of species that are either associated with introduced bivalves or facilitated by aquaculture activities (i.e. structures or husbandry practices). These may include both "hitchhiking" species (organisms that grow in association with or may be transferred with cultured bivalves) and disease causing organisms. Management options should include the use of risk assessments prior to transfers and quarantines. Various types of mitigation for exotic species have been evaluated but are generally not very successful. Because the risk of exotic species to ecosystems and the bivalve farming industry itself may be great, effort should be directed to better predict and halt introductions of potentially harmful species.
The probability of successful dispersal by sessile benthic invertebrates is thought to strongly influence their geographic distribution and population genetics. Generally, species with long-lived planktonic larvae are expected to exhibit wider distribution patterns than those species which brood their young, due to their presumably greater potential for dispersal. In some cases, however, brooding species exhibit broad distributions and show evidence of genetic exchange with geographically distant populations. One potential factor that has been invoked as an expianation is dispersal by floating and rafting of adults and egg masses. Several studies have shown that it is possible for sessile adults to disperse on the order of several to many thousand kilometers by rafting on debris in ocean currents. With very few exceptions, however, direct evidence of rafting in the open ocean has been lacking. We present evidence of long-distance (1300 to 2000 km) dispersal of a brooding pelecypod,Gaimardia trapesina (Lamarck, 1819), in the Southern Ocean in the vicinity of Cape Horn, the Falkland Islands, and the antarctic island South Georgia (54S; 37W). Data on survival and fecundity rates ofG. trapesina and the prevalence of kelp rafts collected during the austral winter of 1993 indicate that dispersal by rafting can occur over ecologically relevant time scales and could potentially serve as a significant means of genetic exchange between populations.
Aquaculture is undergoing a rapid worldwide expansion. Of significant concern is the increasing use of non-native species,
with subsequent escapes of these species and their associated pathogens and parasites posing a serious threat to native biodiversity,
economic value and ecosystem function, particularly in regions rich in endemic species. The contribution of non-native species
to the growth of the global aquaculture industry and the economic benefits that it has brought to many developing countries
cannot be underestimated. However, minimizing the escapes of non-native aquaculture species must be a high priority for resource
managers, conservationists and the aquaculture industry. This paper reviews intentional and unintentional non-native aquaculture
introductions and the environmental consequences that escapes can have on the aquatic environment and presents a potential
system of risk evaluation, management and funding mechanisms to assist in the long term sustainable development of the aquaculture
industry.
We identified different distributions of marine nonindigenous species (NIS) and native species on some artificial structures
versus natural reefs and using experimental manipulations, revealed some possible causal mechanisms. In well-established subtidal
assemblages, numbers of NIS were 1.5–2.5 times greater on pontoons or pilings than on rocky reefs, despite the local species
pool of natives being up to 2.5 times greater than that of NIS. Conversely, on reefs and seawalls, numbers of native species
were up to three times greater than numbers of NIS. Differential recruitment to different positions and types of surfaces
appeared to influence distribution patterns. NIS recruited well to most surfaces, particularly concrete surfaces near the
surface of the water, whilst natives occurred infrequently on wooden surfaces. The position of rocky reefs and seawalls close
to the shore and to the seabed appeared to make them favourable for the recruitment of natives, but this positioning alone
does not hinder the recruitment of NIS. We argue that pontoons and pilings represent beachheads (i.e. entry points for invasion)
for many nonindigenous epibiota and so enhance the spread and establishment of NIS in estuaries. Habitat creation in estuaries
may, therefore, be a serious threat to native biodiversity.
Exotic species are prominent constituents of fouling communities. If exotic fouling organisms colonize or compete better on a wider range of substrate types than native species, this may partially account for their high abundance in estuaries and bays. We used four artificial and four naturally occurring substrate types to compare initial settlement and percent cover of native and exotic fouling species through six months of community development. Both the identity of common taxa and the total number of species colonizing artificial versus natural substrate types were similar. Despite the similarities in species richness, relative abundance patterns between natural and artificial substrate types varied, particularly as the communities developed. Native species were initially in equal abundance on natural and artificial substrate types. Initially, the two most common exotic species, the colonial tunicates, Botrylloides violaceus Ritter and Forsyth and Botryllus schlosseri (Pallas), were also in similar, but low, abundance on artificial and natural substrates. As the communities developed, there was little change in abundance of exotic or native species on natural substrates. However, on artificial substrates the exotic tunicates increased dramatically and native species declined in abundance. Artificial surfaces may provide a novel context for competitive interactions giving exotic species a more “level playing field” in an environment for which they otherwise might not be as well adapted compared to long-resident native species. Additions of artificial substrates to nearshore environments may disproportionately favor exotic species by increasing local sources of exotic propagules to colonize all types of substrates.
Marine debris is one of the most significant issues facing oceans worldwide. The sources of this debris vary depending on proximity to urban centres and the nature of activities within an area. This paper examines the influence of tourism in the southern Great Barrier Reef (GBR), and its contribution to litter levels in the region. By conducting beach debris surveys on occupied and unoccupied islands, this study found that debris was prevalent throughout the region with significant differences in material types between locations. The greatest source of debris from publically accessible islands was tourist-related, with this source also influencing debris loads on nearby uninhabited islands. A focus on debris at Heron Island, showed that sites close to amenities had greater levels of tourist-sourced items like cigarette butts. These findings indicate the contribution of tourists to this problem and that working with operators and managers is needed to minimise visitor impacts.
People take for granted that injuries occur at beaches. But the evidence for injuries caused by beach litter
is lacking within the literature. Therefore, we examined the prevalence of litter related beach injuries at
Tasmanian (Australia) beaches. A risk equation was developed to determine injury risk posed by litter
based on a user's frequency of beach visitation. Examined beaches are considered ‘clean’ (approximately
1.69 kg of debris per beach) using the Clean Coast Index. Moderate proportions (21.6%) of beach users
received injuries from beach litter, illustrating that even clean beaches pose a threat of injury. Realised
risk was high; with wounds (65%) being the most common injury. Daily beach visitation decreased injury
risks (high to moderate/high). Respondents seldom (12.9%) recognise beach litter injuries as a major
concern, instead focussing on impacts that litter in the marine environment (including beaches) has on
marine biota. Respondent's perceptions of cause and responsibility of beach litter are discussed, with
implications provided within a re-education context.
Rapidly growing populations and expanding development are intensifying pressures on coastal ecosystems. Sea-level rise and other predicted effects of climate change are expected to exert even greater pressures on coastal ecosystems, exacerbating erosion, degrading habitat, and accelerating shoreline retreat. Historically, society’s responses to threats from erosion and shoreline retreat have relied on armoring and other engineered coastal defenses. Despite widespread use on all types of shorelines, information about the ecological impacts of shoreline armoring is quite limited. Here we summarize existing knowledge on the effects of armoring structures on the biodiversity, productivity, structure, and function of coastal ecosystems.
Long-distance oceanic rafting is frequently invoked as an explanation for broad geographic distributions of sedentary marine taxa, but evidence for this ecological process remains elusive. We explored empirically the potential of rafting as a dispersal mechanism by comparing circumpolar mtDNA variability in 3 codistributed subantarctic taxa: 2 direct-developing epifaunal crustacean species (Limnoria stephenseni, Parawaldeckia kidderi) and their macroalgal host (Durvillaea antarctica). A previous study of D. antarctica suggests that its subantarctic populations were established only postglacially, and we predict that the epifaunal invertebrates associated with it experienced a parallel island-colonization episode, facilitated by kelp-rafting. We generated and analysed mtDNA sequence data (cytochrome oxidase subunit I [COI] gene, >900 base pairs) from 89 L. stephenseni and 62 P. kidderi specimens and reanalysed previously published comparable data for D. antarctica. Both epifaunal species exhibited wide-scale circumpolar distributions of a single haplotype. Little sequence diversity was found within island samples, with the exception of P. kidderi in the Falkland Islands. The phylogeographic diversity and structuring of the invertebrates was very similar to that of their kelp host and consistent with a scenario of subantarctic recolonization and population expansion. The dependence of these otherwise non-dispersive crustaceans on macroalgal holdfasts for food and habitat, as well as the great abundance of D. antarctica adrift in the Antarctic Circumpolar Current (ACC), support rafting as their most plausible recolonization mechanism. We suggest that macroalgal rafting may explain similarities in the species composition of intertidal marine communities across the subantarctic.
In just 4 decades, marine litter has become abundant in northern oceans and seas and is increasing on even remote Southern Ocean island shores. The Southern Ocean was thought to be protected from rafting organisms by its freezing sea surface temperatures. Here we report on an assemblage of animals attached to a piece of plastic that was washed ashore on Adelaide Island, Antarctic Peninsula (68° S). The band of plastic was positively buoyant. At least 10 species belonging to 5 phyla were present on the plastic and the size of some indicated that it had been afloat for more than a year. Clearly it is possible for a range of animals to survive and grow in such an environment, and so exotic species could enter or leave the Southern Ocean.
Idotea metallica establishes self-sustaining populations exclusively on objects drifting at the sea surface. Large-scale transport of drift material with surface currents results in an efficient dispersal of the species. Two types of drifting objects are utilised (biotic and abiotic), providing quite different conditions of life. Ephemeral biotic substrata (mainly uprooted macroalgae) may be used for transport and food, however, resulting habitat destruction from feeding must be a major threat for local population persistence of I. metallica. Abiotic substrata or wood represent efficient vectors for long-distance dispersal due to their resistance to biodegradation, but do not provide food for this herbivorous species. In laboratory experiments, the spatially-limited conditions of drifting substrata were simulated in microcosms. Idotea metallica established persistent populations on both types of substrata. On abiotic substrata, however, where the animals were fed only on Artemia larvae, high variations in density and a reduced intrinsic rate of population growth increased the risk of population extinction. Idotea metallica avoids habitat destruction by limited feeding on macroalgae. In contrast, the coastally distributed congener Idotea baltica destroyed algal habitats by feeding about 10 times faster than I. metallica.
Artificial structures have become ubiquitous features of coastal landscapes. Although they provide novel habitats for the colonization of marine organisms, their role in facilitating biological invasions has been largely unexplored.
We investigated the distribution and dynamics of the introduced green alga, Codium fragile ssp. tomentosoides , at a variety of spatial scales on breakwaters in the north Adriatic Sea, and analysed experimentally the mechanisms underlying its establishment. We assessed the provision of sheltered habitats by breakwaters, the role of disturbance (e.g. from recreational harvesting and storms) acting at different times of the year, and the interactions between Codium and the dominant native space‐occupier, the mussel Mytilus galloprovincialis .
Codium fragile ssp. tomentosoides has established viable populations on artificial structures along the shores investigated. The density, cover and size (length, branching and weight) of annual erect thalli of Codium was enhanced in sheltered conditions, resulting in the monopolization of landward low‐shore habitats of breakwaters.
On the landward sides of breakwaters, disturbance enhanced recruitment of Codium . The time when bare space was provided within mussels beds was crucial. Removal of mussels in April or January did not affect the recruitment of Codium , whereas harvest in August, shortly before Codium gamete release, doubled its success. On the seaward sides of breakwaters, the effects of disturbance were more complex because mussels both inhibited recruitment of Codium and provided shelter from wave action to adult thalli.
Synthesis and applications . Artificial structures can provide suitable habitats for non‐indigenous marine species and function as corridors for their expansion. Physical (wave exposure) and biotic (resident assemblages) features of artificial habitats can be important determinants of their susceptibility to biological invasions. Alternative options in the design of artificial structures and effective management of native assemblages could minimize their role in biological invasions. In particular, increased water motion and retention of space by mussels in spring–summer would be effective in reducing the ability of C. fragile ssp. tomentosoides to persist on the breakwaters investigated in this study.
Aim To investigate the major paradigms of intense isolation and little anthropogenic influence around Antarctica and to examine the timings and scales of the modification of the southern polar biota.
Location Antarctica and surrounding regions.
Methods First, mechanisms of and evidence for long-term isolation are reviewed. These include continental drift, the development of a surrounding deep-water channel and the Antarctic Circumpolar Current (ACC). They also include levels of endemism, richness and distinctiveness of assemblages. Secondly, evidence for past and modern opportunities for species transport are investigated. Comparative levels of alien establishments are also examined around the Southern Ocean.
Discussion On a Cenozoic time-scale, it is clear that Gondwana's fragmentation led to increasing geographical isolation of Antarctica and the initiation of the ACC, which restricted biota exchange to low levels while still permitting some movement of biota. On a shorter Quaternary time-scale, the continental ice-sheet, influenced by solar (Milankovitch) cycles, has expanded and contracted periodically, covering and exposing terrestrial and continental shelf habitats. There were probably refugia for organisms during each glacial maxima. It is also likely that new taxa were introduced into Antarctica during cycles of ice sheet and oceanic front movement. The current situation (a glacial minimum) is not ‘normal’; full interglacials represent only 10% of the last 430 ka. On short (ecological) time-scales, many natural dispersal processes (airborne, oceanic eddy, rafting and hitch-hiking on migrants) enable the passage of biota to and from Antarctica. In recent years, humans have become influential both directly by transporting organisms and indirectly by increasing survival and establishment prospects via climate change.
Main conclusions Patterns of endemism and alien establishment are very different across taxa, land and sea, and north vs. south of the Polar Frontal Zone. Establishment conditions, as much as transport, are important in limiting alien establishment. Three time-scales emerge as important in the modification of Antarctica's biota. The natural ‘interglacial’ process of reinvasion of Antarctica is being influenced strongly by humans.
This study discusses theoretical and practical issues around the definition of internal borders for the management of marine pests, drawing on principles from freshwater and terrestrial pest management. Internal borders are defined as post‐border intervention points around which vector management and related activities, such as pest surveillance and incursion response, can be undertaken.
Internal borders can be identified in marine systems based on knowledge of natural barriers to the dispersal or establishment of pests, including planktonic life stages. We highlight opportunities to define internal borders at broad spatial scales according to oceanographic features or environmental conditions. At smaller spatial scales, habitat barriers based on relatively permanent features (e.g. substratum) could be defined for target organisms (or suites of similar organisms), especially those having both restricted habitat requirements and a limited planktonic duration.
Where internal borders are identified, risk‐based approaches can be used to determine vector management priorities, incorporating knowledge of the connectivity and strength of interactions between hubs of vector activity. However, greater biosecurity and biodiversity benefits may arise from approaches that combine risk‐based measures for target pests, with generic measures (e.g. vessel hull anti‐fouling) that are applied equally across all human‐mediated invasion pathways.
Case studies of high‐profile marine pests in New Zealand illustrate situations where the benefits of internal border management have been realized. The challenge now is to identify how practical it is to widely apply internal borders in a marine biosecurity context, and to identify new internal borders around which management can practically be undertaken.
Synthesis and applications . Effective control of pest species in marine environments is possible even when they become relatively widespread and established. The definition of internal borders provides an approach to marine biosecurity that assists in elucidating opportunities and priorities for management. Although marine systems are regarded as relatively open, the principles and approaches necessary for the successful management of marine pests are conceptually the same as those applied in freshwater systems and on land.
The drivers (social) and pressures (physical) of marine debris have typically been examined separately. We redress this by using social and beach surveys at nine Tasmanian beaches, across three coastlines and within three categories of urbanisation, to examine whether people acknowledge that their actions contribute to the issue of marine debris, and whether these social drivers are reflected in the amount of marine debris detected on beaches. A large proportion (75%) of survey participants do not litter at beaches; with age, gender, income and residency influencing littering behaviour. Thus, participants recognise that littering at beaches is a problem. This social trend was reflected in the small amounts of debris that were detected. Furthermore, the amount of debris was not statistically influenced by the degree of beach urbanisation, the coastline sampled, or the proximity to beach access points. By linking social and physical aspects of this issue, management outcomes can be improved.
Aquatic nonindigenous species (ANS) have dramatic impact on environmental, economic, social, cultural, and human health values in a variety of coastal, estuarine, and inland ecosystem. Despite efforts to develop biosecurity risk assessment frameworks for the improvement of ANS management, responsible agencies lack a standardized framework to identify and mitigate risk from ANS. This paper reviews the biosecurity risk assessment frameworks of seven international bodies, four regional bodies, and three countries and highlights the similarities, differences and deficiencies in their respective frameworks. Specific deficiencies found by the review include: (i) a lack of national implementation of the international and regional frameworks; (ii) gaps in ANS knowledge; (iii) insufficient guidance for various components of the risk assessment; (iv) limited number and scope of standards and measures related to ANS; and (v) inconsistent terminology between frameworks. To reduce the risk of ANS introductions, this paper concludes with a set of six recommendations to develop aquatic biosecurity risk frameworks that are both comprehensive and precautionary while also in accord with mandates established by other international bodies such as the World Trade Organization.
Marine litter is now recognized as a major form of marine pollution and key factor for coastal managers. The aims of this paper are to: (a) investigate the perception of beach users on aspects related to solid waste pollution and (b) quantify the input of tourism-related litter to the southern Brazilian coastal ecosystem in areas occupied by beach users with different socio-economic characteristics. Interview results indicated that beach users normally do not admit littering on the beach; believe that hazards to humans are the main problem caused by litter; suggest the conduction of education activities and more trash bins for reducing beach contamination. Results indicated that daily litter input to the beach was higher (p<0.01) in the region frequented by people with lower annual income and literacy degree, evidencing the influence of educational level on people environmental awareness and behavior in relation to its own residues. Cigarette butts, followed by plastics are the main kind of litter generated. Strong correlations between beach visitor density and litter generation showed that (1) tourism is the main source of marine debris and (2) beach contamination depends on beach visitor density. The use of southern Brazilian coastal zone has increased very quickly, but environmental awareness of people has not accompanied it. It is evident that litter input and impacts in the oceans will increase if no preventive actions were taken.
Oyster farming in estuaries is a globally important industry based primarily around the Pacific oyster Crassostrea gigas, for which a common technique is elevated culture on racks, trestles and other structures. We review literature on cultivation impacts, revealing a research focus and state of knowledge that largely parallels that for other aquaculture species and cultivation methods. Ecological studies of elevated culture effects have focused on changes to the benthos from biodeposition, and largely show that impacts are localized and minor by comparison with many other forms of aquaculture. The broader ecological issues associated with elevated oyster culture include the effects of pests (fouling pests, toxic/noxious microalgae, disease), creation of novel habitat (e.g. by fouling of farm structures and accumulation of shell), alteration to nutrient cycling, depletion of suspended particulate matter by oyster crops, and related effects on higher trophic level animals including fish, seabirds and marine mammals. These issues are less well understood for elevated culture systems, but ecological effects can be inferred from the few studies that have been conducted, from other forms of bivalve aquaculture (e.g. mussels), and to some extent from fundamental knowledge of the role of oysters as ‘ecosystem engineers’. We use a risk ranking method to evaluate ecological risks (and associated uncertainty intervals) for each of the issues associated with estuarine oyster culture, based on subjective assessment of the likelihood and consequences (severity, spatial extent and duration) of adverse effects. Our assessment reveals that the introduction and spread of pest species are potentially important but often overlooked consequences of oyster cultivation. By comparison with most other sources of impact, the spread of pests by aquaculture activities can occur at regional scales, potentially leading to ecologically significant and irreversible changes to coastal ecosystems. We suggest that future studies of cultivation effects redress the balance of effort by focusing more on these significant issues and less on the effects of biodeposition in isolation. Furthermore, the acceptability of aquaculture operations or new developments should recognize the full range of effects, since adverse impacts may be compensated to some extent by the nominally ‘positive’ effects of cultivation (e.g. habitat creation), or may be reduced by appropriate planning and management. Even more broadly, aquaculture developments should be considered in relation to other sources of environmental risk and cumulative impacts to estuarine systems at bay-wide or regional scales, so that the effects of cultivation are placed in context.
Coastal areas play a crucial role in the economical, social and political development of most countries; they support diverse and productive coastal ecosystems that provide valuable goods and services. Globally flooding and coastal erosion represent serious threats along many coastlines, and will become more serious as a consequence of human-induced changes and accelerated sea-level rise. Over the past century, hard coastal defence structures have become ubiquitous features of coastal landscapes as a response to these threats. The proliferation of defence works can affect over half of the shoreline in some regions and results in dramatic changes to the coastal environment. Surprisingly little attention has been paid to the ecological consequences of coastal defence. Results from the DELOS (Environmental Design of Low Crested Coastal Defence Structures, EVK3-CT-2000-00041) project indicate that the construction of coastal defence structures will affect coastal ecosystems. The consequences can be seen on a local scale, as disruption of surrounding soft-bottom environments and introduction of new artificial hard-bottom habitats, with consequent changes to the native assemblages of the areas. Proliferation of coastal defence structures can also have critical impacts on regional species diversity, removing isolating barriers, favouring the spread of non-native species and increasing habitat heterogeneity. Knowledge of the environmental context in which coastal defence structures are placed is fundamental to an effective management of these structures as, while there are some general consequences of such construction, many effects are site specific. Advice is provided to meet specific management goals, which include mitigating specific impacts on the environment, such as minimising changes to surrounding sediments, spread of exotic species or growth of nuisance species, and/or enhancing specific natural resources, for example enhancing fish recruitment or promoting diverse assemblages for eco-tourism. The DELOS project points out that the downstream effects of defence structures on coastal processes and regional-scale impacts on biodiversity necessitate planning and management at a regional (large coastline) scale. To effectively understand and manage coastal defences, environmental management goals must be clearly stated and incorporated into the planning, construction, and monitoring stages.
All but one of the nine non-native marine species that established populations in the southern Gulf of St. Lawrence (sGSL) in the past decade initially invaded the sGSL via coastal and estuarine waters of Prince Edward Island (PEI). Almost half of these species are tunicates, and all but one still occur only in PEI. Recent introductions include Styela clava Herdman in 1997, Botryllus schlosseri (Pallas) in 2001, Botrylloides violaceus Oka in 2002, and Ciona intestinalis (Linnaeus) in 2004. The goal of this paper was to investigate which characteristics of PEI estuaries may have resulted in their being more susceptible to tunicate invasions than estuaries elsewhere in the sGSL. At least one genus that recently established viable populations in PEI was previously introduced to the Gulf of St. Lawrence, apparently without establishing permanent populations. This implies that either propagule pressure has increased or environmental factors are more conducive to establishment now than they were previously. The fluctuating resource availability model predicts increased invasibility of environments that experience pulses of resources such as space or nutrients. Intense development of both agriculture and aquaculture in PEI, and high population density compared to other areas of the sGSL, are associated with high and fluctuating estuarine nutrient levels and a large surface area of artificial substrates (mussel socks) that is kept relatively free of competitors, and is replaced regularly. Changes in nutrient loading and the development of aquaculture have also occurred within the past two to three decades. The provision of artificial structure is likely a critical factor in the successful establishment of tunicates in PEI, because natural hard substrates are scarce. Facilitation by green crabs (Carcinus maenas L.) may be a contributing factor in the spread of Styela. Only one estuary lacking green crabs has an established population of Styela, and at least two known inoculations of Styela into estuaries without green crabs have failed. A likely mechanism for facilitation is the consumption by green crab of the snail Astyris lunata, a known Styela predator.
It is widely perceived that litter diminishes appreciation of environmental quality, and therefore may require management. Litter in coastal-marine environments has not been studied intensively, although these are likely to be encountered by humans. In order to assess the severity of litter impacts, we studied the existing litter fauna of shallow embayments in north-eastern New Zealand, in an area where boating is intense. We sought an understanding of existing patterns of litter distribution, how long litter items might take to break down or disperse, and considered possible management options.The distribution, abundance, and persistence of subtidal benthic litter were studied at Kawau Island, north-eastern New Zealand, where high densities of pleasure craft concentrated in sheltered bays during summer. A survey of the benthic subtidal environment at 37 sites found numerous litter items. Glass beer bottles dominated sites with histories of high boating usage, but litter was sparse elsewhere. Litter items placed at a popular anchorage were displaced and rapidly lost, whereas at an infrequently visited site nearby their abundances declined more slowly. Tin cans and to a lesser extent aluminium cans showed signs of physical decay over a 10-month experimental deployment, while glass and plastic did not.Although litter is locally very abundant, it does not currently affect most users, and attempts to remove it would be a more intense disturbance than any existing impact. We suggest that the appropriate management approach is to reduce the amount of litter that arrives in the shallow coastal area, by providing rubbish collection facilities over the period of intensive usage in summer.