ArticleLiterature Review

Impacts of recreational motorboats on fishes: A review

Authors:
  • Department of Primary Industries, Port Stephens Fisheries Institute
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Abstract

A considerable amount of research has been conducted on the impacts of recreational boating activities on fishes but little or no synthesis of the information has been undertaken. This review shows that motor boats impact on the biology and ecology of fishes but the effects vary according to the species and even particular size classes. Direct hits on fishes by propellers are an obvious impact but this aspect has been poorly documented. Alterations in the wave climate and water turbidity may also influence fishes and their habitats, especially submerged and emergent plant beds. Sound generated by boat motors can also influence the communication and behaviour of certain species. Pollution arising from fuel spillages, exhaust emissions and antifouling paints all have detrimental effects on fishes. Finally, the use of recreational boats as vectors of aquatic invasive organisms is very real and has created major problems to the ecology of aquatic systems.

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... Boating may also have a combination of direct and indirect impacts on demersal fish assemblages. Altered wave climate in shallow wave-protected areas due to high-speed boating and water turbidity due to sediment resuspension may influence fishes and their habitats, especially in submerged aquatic vegetation [114]. Finally, the role of recreational boats as vectors of aquatic invasive organisms is also a significant concern and has created major problems for the ecology of aquatic systems [114]. ...
... Altered wave climate in shallow wave-protected areas due to high-speed boating and water turbidity due to sediment resuspension may influence fishes and their habitats, especially in submerged aquatic vegetation [114]. Finally, the role of recreational boats as vectors of aquatic invasive organisms is also a significant concern and has created major problems for the ecology of aquatic systems [114]. ...
... Another chronic impact of recreational navigation is the release of pollutants from boat exhaust, fuel leaks, liquid and solid wastes, and other sources, including heavy metals [118], that combined with anoxic sediment mechanical resus- [114] and in other demersal fauna [119]. ...
... Here, using experiments exposing fish to real motorboats in field conditions on Australia's Great Barrier Reef, we tested how body condition influences the responses of a common coral reef fish (the blue-green damselfish, Chromis viridis) to anthropogenic noise. In coastal marine habitats, recreational motorboats represent a large proportion of marine traffic [19], and their use is forecast to increase considerably over the next few decades, owing to human population growth and development of tourism, fishing and transport [19,20]. While motorboats also generate wake and visual disturbances, the noise component propagates the furthest. ...
... Here, using experiments exposing fish to real motorboats in field conditions on Australia's Great Barrier Reef, we tested how body condition influences the responses of a common coral reef fish (the blue-green damselfish, Chromis viridis) to anthropogenic noise. In coastal marine habitats, recreational motorboats represent a large proportion of marine traffic [19], and their use is forecast to increase considerably over the next few decades, owing to human population growth and development of tourism, fishing and transport [19,20]. While motorboats also generate wake and visual disturbances, the noise component propagates the furthest. ...
... orientation, communication, foraging, anti-predator responses) and physiology (e.g. opercular beat rate (OBR), metabolic rate, heart rate) of fishes, with direct consequences for fitness [19,21,23]. Here, we aimed to determine whether intraspecific variation in body condition affects noise impacts, measuring the behavioural and physiological responses of fish in relatively good and poor condition to motorboat noise compared to ambient sound. ...
Article
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Anthropogenic noise is a pollutant of global concern that has been shown to have a wide range of detrimental effects on multiple taxa. However, most noise studies to-date consider only overall population means, ignoring the potential for intraspecific variation in responses. Here, we used field experiments on Australia's Great Barrier Reef to assess condition-dependent responses of blue-green damselfish ( Chromis viridis ) to real motorboats. Despite finding no effect of motorboats on a physiological measure (opercular beat rate; OBR), we found a condition-dependent effect on anti-predator behaviour. In ambient conditions, startle responses to a looming stimulus were equivalent for relatively poor- and good-condition fish, but when motorboats were passing, poorer-condition fish startled at significantly shorter distances to the looming stimulus than better-condition fish. This greater susceptibility to motorboats in poorer-condition fish may be the result of generally more elevated stress levels, as poorer-condition fish had a higher pre-testing OBR than those in better condition. Considering intraspecific variation in responses is important to avoid misrepresenting potential effects of anthropogenic noise and to ensure the best management and mitigation of this pervasive pollutant.
... If the use of the water for bathing can be considered a minor impact that can be neglected, the continual circulation of motorboats and jet skis is an impact that Environments 2020, 7, 88 9 of 20 has to be considered, since they cause discomfort to the space users. The negative impacts associated with recreational boats include noise, constant agitation of the water, shock to animals and pollution by hydrocarbons, as stated by Whitfield and Becker (2014) and Sim et al. (2015) [76,77]. However, perhaps the most important negative impact is the permanent intrusion of tourist transport boats in the hundreds of small rocky coves, caves and other many similar formations in the region of Algarve [78]. ...
... If the use of the water for bathing can be considered a minor impact that can be neglected, the continual circulation of motorboats and jet skis is an impact that Environments 2020, 7, 88 9 of 20 has to be considered, since they cause discomfort to the space users. The negative impacts associated with recreational boats include noise, constant agitation of the water, shock to animals and pollution by hydrocarbons, as stated by Whitfield and Becker (2014) and Sim et al. (2015) [76,77]. However, perhaps the most important negative impact is the permanent intrusion of tourist transport boats in the hundreds of small rocky coves, caves and other many similar formations in the region of Algarve [78]. ...
... If the use of the water for bathing can be considered a minor impact that can be neglected, the continual circulation of motorboats and jet skis is an impact that has to be considered, since they cause discomfort to the space users. The negative impacts associated with recreational boats include noise, constant agitation of the water, shock to animals and pollution by hydrocarbons, as stated by Whitfield and Becker (2014) and Sim et al. (2015) [76,77]. However, perhaps the most important negative impact is the permanent intrusion of tourist transport boats in the hundreds of small rocky coves, caves and other many similar formations in the region of Algarve [78]. ...
Article
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Tourism activity has a very significant weight in the world economy, even being the main activity responsible for the export of many countries, in the form of providing services to foreign citizens. In mainland Portugal, the main tourist region is the Algarve, where beach tourism, known as sun and sea tourism, plays a decisive role. However, this activity also has its negative impacts. In the present work, a case study was analyzed, at Praia da Cova Redonda, located in the parish of Porches, in the municipality of Lagoa. Negative impacts on land use and occupation were identified, caused by the excessive presence of people, the introduction of invasive species and the artificial filling of beaches. At the end, a set of mitigating measures are presented that aim to ensure that the exploitation of natural resources can be maintained, but in a perspective of preservation and recovery of natural resources and biodiversity.
... The Centrarchidae are a speciose family of freshwater fishes native to North America, although widely introduced in warm waters globally (Berra, 2001). As both forage fish and popular recreationally angled species, the Centrarchids are important components of freshwater ecosystems in which they occur, but it remains unclear how they might be affected by the increasing problems of anthropogenic noise of interest worldwide (Popper and Hastings, 2009;Slabbekoorn et al., 2010;Whitfield and Becker, 2014). Thus, this family can be a useful model for examination of interspecific differences in hearing ability as well as important metrics for how noise may impact freshwater ecosystems once their basic hearing abilities have been determined. ...
... Despite the differences in AEP detection thresholds, there were no statistical interspecific differences in behavioral responses to sound. Although no statistical differences were found, these behavioral responses can still provide useful information on how a fish interacts with their environment and can be used to predict potential responses to acoustic stimuli, which is vital given the rise in underwater anthropogenic noise (Popper and Hastings, 2009;Slabbekoorn et al., 2010;Whitfield and Becker, 2014). In previous research, it has been common to use classical, operant, or reward conditioning to determine when a fish can hear different sounds; however, conditioning requires fish to be trained to communicate with the researcher when they are able to detect the acoustic stimuli they are being presented with (Popper and Hawkins, 2021). ...
Article
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There exists a wealth of knowledge on hearing ability in individual fish species, but the role of interspecific variation, and drivers behind it, remains understudied, making it difficult to understand evolutionary drivers. The current study quantified hearing thresholds for three species of sunfish in the family Centrarchidae [bluegill sunfish (Lepomis macrochirus), pumpkinseed sunfish (Lepomis gibbosus), and rock bass (Ambloplites rupestris)] using auditory evoked potentials and behavioral trials and saccular otolith size and hair cell density. In auditory physiological experiments, 10-ms tone bursts were played and responses monitored to measure hearing. In behavioral experiments, fish were exposed to the same tone bursts for 1 s, and changes in fish behaviors were monitored. Saccular otolith morphology and hair cell densities were also quantified. Physiological thresholds varied between species, but behavioral thresholds did not. Rock bass had larger S:O ratio (percentage of the saccular otolith surface occupied by the sulcus), but no differences in hair cell densities were found. Our study allows for a direct comparison between confamilial species, allowing a deeper understanding of sound detection abilities and possible mechanisms driving differential hearing. Using both approaches also allows future research into how these species may be impacted by increasing levels of anthropogenic noise.
... Zn content occurrence in MMFR is due to wastewater disposal from agriculture and manufacture activities around the area (Khan et al., 2020). Thus, this metal is coming from landward zone and suspended into sediment layers (Whitfield & Becker, 2014). Chromium content at different mangrove zones at three locations is illustrated in Figure 10. ...
... Pb is widely used in gasoline or diesel for boat engine (Mosisch & Arthington, 1998;Mohamad Pazi et al., 2021). Thus, a leaking or spilled gasoline from engine boat can increase Pb content in the sediment river, especially in upper sediment depth (Whitfield & Becker, 2014). ...
Article
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Heavy metal concentrations have risen throughout Malaysia's coastline because of industrial wastewater discharge, affecting mangrove ecology significantly. Lead (Pb), Zinc (Zn), Chromium (Cr), and Nickel (Ni) were used to establish the Mangrove Sediment Quality Index (MSQi), which assesses and monitors the quality of mangrove sediment. This study was conducted at Matang Mangrove Forest Reserve (MFFR) in Perak, Malaysia to examine changes in MSQi features across seasons, mangrove zones, and sediment depths at three separate MMFR locations. Sediment samples were taken using auger in two different seasons (dry and wet seasons). After the silt was removed using aqua regia techniques, heavy metals were examined using an Atomic Absorption Spectrophotometer. According to MSQi criteria in various seasons at three different locations, the highest concentration of heavy metals (HMs) was detected in the dry season in the least disturbed region at three different locations. During dry seasons, only Cr and Ni levels are higher in moderately and highly disturbed areas. Pb and Zn levels in moderately and highly disturbed areas are higher than in least disturbed areas during the rainy season. MSQi parameters in different mangrove zones at three locations showed that most HMs content is highest in the landward zone and it can be concluded that HMs sources are anthropogenic. Furthermore, MSQi measurements at three locations revealed that heavy metals content is highest at 0-15 cm and lowest at other depths.
... However the greatest negative impact is associated with internal or external combustion engines. These include fish scaring and nesting disturbances [68], plant fragmentation [69,70], and environmental contamination by operating fluids [70]. ...
... However the greatest negative impact is associated with internal or external combustion engines. These include fish scaring and nesting disturbances [68], plant fragmentation [69,70], and environmental contamination by operating fluids [70]. ...
Article
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Recreational specialization is characteristic of many activities, including recreational fishing, which is a popular and important form of recreation throughout the world. The pressure on the environmental resources used by anglers is increasing. It is becoming crucial to understand the preferences and behaviors of anglers, which can accumulate and multiply the risk of damage to fish stocks and aquatic habitats. The main objective of the study was to comprehensively analyze the differences between anglers with diverse specialization profiles. By investigating the fishing preferences within the context of the socioeconomic, demographic and engagement factors, three groups of anglers were identified: anglers who specialize in predatory fish, anglers who specialize in non-predatory fish and unspecialized anglers. Specialized anglers, regardless of type, were found to be more supportive of releasing caught fish (71% on average) and were less likely to keep them (16%) than unspecialized anglers (55% and 27%, respectively). Unspecialized anglers (26.5% of the surveyed population) show less commitment to ethical values. The potential negative environmental impact of the least specialized anglers is an accumulation of the preferences for the use of ground bait, artificial lures, and live fish as bait. Anglers specializing in predatory fish are the most critical in their evaluation of fish resources and water quality and are least attached to specific fisheries. This work provides insight into angler experience and it may help to better identify anglers who are disrespectful towards the fishing laws in place. The results of this work may be incorporated into fishery management strategies, including strategies to reduce naïve anglers and deter disrespectful anglers, which are lucrative in the fishing process.
... The impacts of anthropogenic stressors on shark nursery areas can be difficult to quantify (Ward-Paige et al., 2015). However, as human population densities within 100 km of the ocean exceed triple the global mean, it is crucial to understand these impacts on wildlife, particularly near coastal metropolitan areas such as those examined in this study (reviewed in Whitfield & Becker, 2014). The results of the BRT indicate nearshore coastal areas characterized by shallow, warm, seagrass environments provide critical habitat for shark species and immature sharks in general. ...
... Management in the form of NOAA's marine protected areas (MPAs), which largely regulate public access and activities, has been shown to increase fish abundance in the coastal waters of Florida (Bohnsack, 2011) and in other tropical regions (Bond et al., 2012). Strikes from boat propellers may be fatal, but sites subject to boat wakes have also been associated with lower levels of faunal abundance and diversity, as well as destruction of essential seagrass habitat (Whitfield & Becker, 2014). Immature individuals are particularly vulnerable to boat strikes, and a loss of seagrass structures would likely result in a decrease in prey availability and a loss of threedimensional structure in which immature individuals find protection from predators. ...
Article
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Identifying critical habitat for highly mobile species such as sharks is difficult, but essential for effective management and conservation. In regions where baseline data are lacking, non-traditional data sources have the potential to increase observational capacity for species distribution and habitat studies. In this study, a research and education organization conducted a 5-year (2013–2018) survey of shark populations in the coastal waters of west-central Florida, an area where a diverse shark assemblage has been observed but no formal population analyses have been conducted. The objectives of this study were to use boosted regression tree (BRT) modeling to quantify environmental factors impacting the distribution of the shark assemblage, create species distribution maps from the model outputs, and identify spatially explicit hot spots of high shark abundance. A total of 1036 sharks were captured, encompassing eleven species. Abundance hot spots for four species and for immature sharks (collectively) were most often located in areas designated as “No Internal Combustion Engine” zones and seagrass bottom cover, suggesting these environments may be fostering more diverse and abundant populations. The BRT models were fitted for immature sharks and five species where n > 100: the nurse shark (Ginglymostoma cirratum), blacktip shark (Carcharhinus limbatus), blacknose shark (C. acronotus), Atlantic sharpnose shark (Rhizoprionodon terraenovae), and bonnethead (Sphyrna tiburo). Capture data were paired with environmental variables: depth (m), sea surface temperature (°C), surface, middle, and bottom salinity (psu), dissolved oxygen (mg/L), and bottom type (seagrass, artificial reef, or sand). Depth, temperature, and bottom type were most frequently identified as predictors with the greatest marginal effect on shark distribution, underscoring the importance of nearshore seagrass and barrier island habitats to the shark assemblage in this region. This approach demonstrates the potential contribution of unconventional science to effective management and conservation of coastal sharks.
... Acoustic investigations of freshwater soundscapes can be grouped (S1 Table and citations therein) into those that seek to characterize the ambient noise [2,[10][11][12][13][14][15][16][17][18][19][20], those that focus on the biophony (without reporting on anthropophony) [21][22][23][24][25][26][27], those that focus on noise impacts on fishes and other organisms (see reviews in [8,[28][29][30]), and those that include some information on both the biophony and anthropophony [31][32][33][34][35][36][37][38][39][40][41][42][43]. Most of the latter studies focus on sound levels and do not provide information on the relative contribution of both the biophony and anthropophony to the soundscape in terms of percent occurrence, number of sounds, percent of time occupied, or diversity (except [31,32,35,36,40] S1 Table). ...
... The underwater soundscape of freshwater habitats was sampled in a roving survey within a 46,000 km 2 region along the corridors of five major rivers in the New England region of North America over a five-week period from 30 April to 29 May 2008 (Fig 1, all location and metadata are provided in S1 Data set). River corridors surveyed included the 653 km Connecticut River (30 April to 3 May, N = 32), 188 km Merrimack River (12)(13)(14)(15)(16) May, N = 43), 270 km Kennebec River (17)(18)(19)(20)(21)(22)(23) May, N = 53), 219 km Saco River (26)(27)(28) May, N = 31) and 42 km Presumpscot River (28)(29)N = 14). Within these five major rivers, sound recordings were made from shore within the main stems of each major river from its origin in the mountains or major lakes to its outlet to the sea, except for the Connecticut River where only the lower 200 km were surveyed (N = 20, 18, 20, 16, and 5 locations for the Connecticut, Merrimack, Kennebec, Saco, and Presumpscot, respectively). ...
Article
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The soundscape composition of temperate freshwater habitats is poorly understood. Our goal was to document the occurrence of biological and anthropogenic sounds in freshwater habitats over a large (46,000 km²) area along the geographic corridors of five major river systems in North America (Connecticut, Kennebec, Merrimack, Presumpscot, and Saco). The underwater soundscape was sampled in 19 lakes, 17 ponds, 20 rivers and 20 streams, brooks and creeks that were grouped into broad categories (brook/creek, pond/lake, and river). Over 7,000 sounds were measured from 2,750 minutes of recording in 173 locations over a five-week period in the spring of 2008. Sounds were classified into major anthropophony (airplane, boat, traffic, train and other noise) and biophony (fish air movement, also known as air passage, other fish, insect-like, bird, and other biological) categories. The three most significant findings in this study are: 1) freshwater habitats in the New England region of North America contain a diverse array of unidentified biological sounds; 2) fish air movement sounds constitute a previously unrecognized important component of the freshwater soundscape, occurring at more locations (39%) and in equal abundance than other fish sounds; and 3) anthropogenic noises dominate the soundscape accounting for 92% of the soundscape by relative percent time. The high potential for negative impacts of the anthropophony on freshwater soundscapes is suggested by the spectral and temporal overlap of the anthropophony with the biophony, the higher received sound levels of the anthropophony relative to the biophony, and observations of a significant decline in the occurrence, number, percent time, and diversity of the biophony among locations with higher ambient received levels. Our poor understanding of the biophony of freshwater ecosystems, together with an apparent high temporal exposure to anthropogenic noise across all habitats, suggest a critical need for studies aimed at identification of biophonic sound sources and assessment of potential threats from anthropogenic noises.
... Engineered structures that provide holes, crevices, overhangs and caves to increase structural complexity and provide additional hard substrate for epibenthic attachment can support increased fish diversity, abundance and biomass at otherwise topographically simple MMSs (Hunter and Sayer 2009;Champion et al. 2015). Because boat access is heavily regulated and limited at the Busselton Jetty, this management approach may also facilitate positive outcomes for MMSs aiming to improve their ecological value (Whitfield and Becker 2014). Yet, not all environments will respond in the same way to the installation of artificial structures (Chapman and Underwood 2011), so ongoing monitoring and adaptive management are essential to ensure that the outcomes of the structure align with its initial ecological goals (Baine 2001;Morris et al. 2018). ...
Article
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Context In Western Australia, the heritage-listed Busselton Jetty is a popular tourism, fishing and diving destination renowned for its unique marine communities. Aims This research describes and quantifies the fish assemblages (mean number of individuals, species diversity and biomass) at the Busselton Jetty, and makes comparisons with natural habitats in Geographe Bay. Methods Diver-operated stereo-video systems filmed 25-m transects along the length of the jetty, and a remotely operated vehicle stereo-video filmed 25-m transects in nearby reef, seagrass and sand habitats. Fish at all habitats were counted, identified and measured. Results Fish assemblages at the defined inshore, mid-shore and offshore zones of the jetty differed significantly, whereas the number of fish, species diversity and biomass increased with distance from shore. There was no measurable effect of protection within the small sanctuary zone at the end of the jetty. Fish assemblages at the jetty differed from those in all three natural habitats, and the number of fish, species diversity and biomass were highest at the natural reef, followed by the jetty, the seagrass and the sand habitats. Conclusions The Busselton Jetty supports a distinctive fish assemblage, high species diversity and a variety of benthic communities. Changes in the fish assemblages were attributed to differences in habitat type, complexity, depth and distance from shore. Implications The ecological and social benefits of future man-made marine structures can be optimised by incorporating design features that promote habitat diversity and complexity.
... Recreational watersports, such as diving, swimming, motorboating, kayaking, water skiing etc., may cause disturbance to anguillid eels and degrade inland aquatic habitats (Whitfield & Becker 2014, Schafft et al. 2021. Stopping or restricting such activities may help to reduce the intensity of these threats and potentially allow anguillid eel populations to persist or recover over time. ...
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... Tourism activities associated with the maritime sector play an important role in the socio-economic development of the coastal regions [1]. However, negative impacts resulting from marine traffic (e.g., underwater noise, chemical pollution) are known to disturb biological communities and marine habitats-for instance, by reducing biodiversity and inducing changes in animals' behavior [2][3][4]. Among the different forms of marine pollution, underwater noise generated by human activities and its potential negative effects on marine ecosystems has gained ever more attention [5], particularly when concerning impacts on marine mammals (e.g., ref. [6]). ...
Article
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Recent years have seen a notable rise in dolphin-watching boat activities along the Algarve coast in Portugal, potentially affecting the common dolphin (Delphinus delphis) and bottlenose dolphin (Tursiops truncatus) local populations. This study examines the impact of increasing underwater noise levels from these boats on dolphin vocalizations. Field recordings were conducted from June to September 2022, analyzing dolphin whistles in various boat presence scenarios. The results indicate significant changes in whistle-frequency characteristics with boat presence, including increased start, low, and high frequencies, alongside a decrease in the number of inflection points in modulated whistles. The changes might negatively impact dolphin populations viability, underscoring the need for further research. Additionally, improved mitigation strategies may be necessary to reduce the potential negative effects of dolphin watching on cetacean communication and behavior in the Algarve region.
... The shows that motor boats impact on the biology and ecology of fishes but the effects vary according to the species and even particular size classes. Pollution arising from fuel spillages exhaust emissions and antifouling paints all have detrimental effects on fishes [31]. The effect of chemical pollution on the quantitative indicators of commercial ichthyofauna can only be compared with such factors as disturbances of natural reproduction and poaching [9]. ...
Article
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The article presents an analytical review of the current ecological state of the mouth area of the Don River, which is conventionally divided into three sections: from the village of Razdorskaya to the top of the delta in the area of Rostov-on-Don, the delta and the Taganrog Bay. Various methods have been used in the literature to assess pollution in the Lower Don. However, a comprehensive review that systematically describes and analyzes all existing contaminants has yet to be conducted. To address this research gap, the authors conduct an analytical review. Particular attention is paid to indicators characterizing the level of organic and biological pollution of river water, the main sources of pollution and their impact on the sanitary, hygienic and epidemiological state of water areas are identified. In 2022-2023, with the participation of the authors, seasonal studies of water were carried out to assess the ecological and sanitary state of the Don and Temernik rivers within the city of Rostov-on-Don based on the use of various microbiological indicators. The set of typical environmental management problems is supplemented by issues related to the reduction of water flow and sediment load of the river. The most vulnerable sectors in this regard are shipping, agriculture and fisheries. The ecological situation in the mouth area of the Don River continues to remain tense, as evidenced by data from hydrochemical and sanitary-bacteriological studies of water, bottom sediments and aquatic organisms.
... These disturbances and others may have a diversity of negative effects on the ecology of the river, including water quality and fish communities. Effects to fishes can be chronic (physiological stress) or acute (physical displacement), and lethal (propeller entrainment, stranding onshore) or sublethal (avoidance of preferred habitat, diminished awareness of predators) (Wolter et al., 2004, Wolter and Arlinghaus, 2003, Whitfield and Becker, 2014, Gabel et al., 2017. ...
... For example, the underwater soundscape of a river changes abruptly in sound intensity and spectral signature over short distances and depending on the flow regime (Kacem et al., 2020;Tonolla et al., 2010Tonolla et al., , 2011Wysocki et al., 2007). Furthermore, the soundscape is modified by anthropogenic sounds originating from different sources, such as recreational motorboats and shoreline activities (Whitfield & Becker, 2014;Wysocki et al., 2007). A portrait of the underwater soundscape across 173 locations (i.e., lakes, ponds, and rivers) showed that sounds produced by motorboats and aquatic organisms overlap in their peak frequencies (Rountree et al., 2020). ...
Article
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Freshwater fishes exhibit a wide range of auditory adaptations and capabilities, which are assumed to help them navigate their environment, avoid predators, and find potential mates. Yet, we know very little about how freshwater environments sound to fish, or how fish with different auditory adaptations respond to different soundscapes. We first compiled data on fish hearing acuity and adaptations and provided a portrait of how anthropogenic sounds compare to natural sounds in different freshwater soundscapes. We then conducted a sound‐enrichment field experiment at Lake Saint Pierre, a large fluvial lake in Canada, to evaluate the effect of motorboat sound exposure on the fish community by looking at the extent to which changes in species abundances were linked to auditory adaptations. Data compilation showed that the hearing acuity of most species overlaps with a wide range of ambient and anthropogenic underwater sounds while the field experiment showed that species with more specialized auditory structures were captured less often in sound‐enriched traps, indicating avoidance behavior. Our findings highlight the importance of considering species' sensorial adaptations when evaluating the community‐scale effects of anthropogenic sounds on the fish community, especially at low levels of anthropogenic activity.
... While marine aquaculture has positive effects on biodiversity in marine ecosystems-it has the potential to create habitats that enhance local biodiversity, such as kelp forests ( In a case study of whale strandings, the predominant anthropogenic cause of large cetacean death off the coast of France (12.9%) was ship strikes (Peltier et al. 2019). Boats (and ballast water) also act as vectors transporting invasive nonnative aquatic species (Burgin and Hardiman 2011; Whitfield and Becker 2014). Boat traffic and mooring infrastructure can also negatively impact aquatic vegetation (Sagerman et al. 2020). ...
Technical Report
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Natural and working lands (NWLs) provide many benefits to people, including storing greenhouse gases (GHGs), supporting biodiversity, and generating other ecosystem services. Management of NWLs can influence their condition and function and therefore the benefits they provide. This project surveys the synthesis literature to assess how different management actions on various types of NWLs affect biodiversity and GHG outcomes. This information can help to determine how to best manage these lands to contribute to both biodiversity and climate solutions in the United States. These results are a starting point to assess how different forms of management on various types of NWLs contribute to or detract from biodiversity and GHG outcomes. Though this study’s scope was limited to an exploration of biodiversity and GHG benefits provided by NWLs, this process could be adapted to examine the effects of management on other important ecosystem services, as well as how management affects equitable distribution of those services. Additional quantitative synthesis is also needed to compare the magnitude of different management activities’ impacts on biodiversity and carbon and to better understand how the intensity of certain activities influences these outcomes. This report is a collaboration between the Nicholas Institute for Energy, Environment & Sustainability and the Gund Institute for Environment at the University of Vermont. This research was supported by the US Department of Agriculture, Office of Environmental Markets, under a cooperative agreement. The findings and conclusions in this report are those of the authors and should not be construed to represent any official USDA or US Government determination or policy.
... Effects of human presence have been assessed for marine mammals, sharks, birds, turtles [2] and in freshwater systems [8]. Boat noise is known to impact fish stress and communication [9], predation mortality [10] and larval settlement [11]. ...
Article
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Humans alter ecosystems through both consumptive and non-consumptive effects. Consumptive effects occur through hunting, fishing and collecting, while non-consumptive effects occur due to the responses of wildlife to human presence. While marine conservation efforts have focused on reducing consumptive effects, managing human presence is also necessary to maintain and restore healthy ecosystems. Area closures and the tourism freeze related to the COVID-19 pandemic provided a unique natural experiment to measure the effects of decreased tourism on fish behavior in a high use no-take marine protected area (MPA) in Hawai`i. We found that when tourism shut down due to COVID restrictions in 2020, fish biomass increased and predatory species increased usage of shallow habitats, where tourists typically concentrate. When tourism resumed, fish biomass and habitat use returned to pre-pandemic levels. These displacement effects change fish community composition and biomass, which could affect key processes such as spawning, foraging and resting, and have knock-on effects that compromise ecosystem function and resilience. Managing non-consumptive uses, especially in heavily-visited MPAs, should be considered for sustainability of these ecosystems.
... Scar areas also support lower macrofaunal abundance and diversity relative to SAV (Uhrin and Holmquist 2003). In addition to SAV impacts, turbidity generated by propellers can disrupt or even bury newly settled shellfish (MacFarlane 1996) and finfish eggs (Whitfield and Becker 2014). ...
Article
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Small docks and floats are common in estuaries and coastal waters worldwide. These structures serve a role in coastal recreation by facilitating access to waterways. However, they can impact shoreline ecological function. While individual environmental impacts are generally minor, increasing dock proliferation and overlap with sensitive coastal resources can result in cumulative impacts that pose threats at the ecosystem level. Docks promote changes in habitat and aquatic communities through alteration of environmental conditions. Here, we review the potential environmental impacts of docks on estuarine and coastal flora and fauna and discuss best management practices (BMPs) to avoid or minimize such impacts with a focus on New England. We consider impacts in relation to the structural components of docks: the piles, decking, and floats. Impacts to salt marsh and submerged aquatic vegetation are a particular focus given the important ecosystem services these vegetated habitats provide and their vulnerability to dock-induced habitat alteration. Potential environmental impacts depend on structure size, design, and location, and can include both short-term (e.g., turbidity from pile installation) and long-term (e.g., salt marsh loss from chronic shading) effects. Such effects can be minimized through BMPs (e.g., construction outside sensitive time-of-year periods, designs to reduce shading). As BMPs tend to reduce rather than avoid environmental effects, cumulative impacts also need to be considered in the permitting process. We recommend that managers develop plans or bylaws that identify sensitive habitats where dock construction should be avoided as well as BMPs to make remaining dock proliferation less impactful.
... There has been a considerable amount of research documenting impacts from recreational boating on fish (Whitfield and Becker, 2014). Similarly, vessel presence has been shown to negatively impact marine mammals behavior. ...
Article
Open Access link: https://doi.org/10.1016/j.scitotenv.2022.160987 - An increasing number of marine conservation initiatives rely on data from Automatic Identification System (AIS) to inform marine vessel traffic associated impact assessments and mitigation policy. However, a considerable proportion of vessel traffic is not captured by AIS in many regions of the world. Here we introduce two complementary techniques for collecting traffic data in the Canadian Salish Sea that rely on optical imagery. Vessel data pulled from imagery captured using a shore-based autonomous camera system ("Photobot") were used for temporal analyses, and data from imagery collected by the National Aerial Surveillance Program (NASP) were used for spatial analyses. The photobot imagery captured vessel passages through Boundary Pass every minute (Jan-Dec 2017), and NASP data collection occurred opportunistically across most of the Canadian Salish Sea (2017-2018). Based on photobot imagery data, we found that up to 72 % of total vessel passages through Boundary Pass were not broadcasting AIS, and in some vessel categories this proportion was much higher (i.e., 96 %). We fit negative binomial General Linearized Models to our photobot data and found a strong seasonal variation in non-AIS, and a weekend/weekday component that also varied by season (interaction term p < 0.0001). Non-AIS traffic was much higher during the summer (Apr-Sep) and during the weekend (Sat-Sun), reflecting patterns in recreational vessel traffic not obligated to broadcast AIS. Negative binomial General Additive Models based on the NASP data revealed strong spatial associations with distance from shore (up to 10 km) and non-AIS vessel traffic for both summer and winter seasons. There were also associations between non-AIS vessels and marina and anchorage densities, particularly during the winter, which again reflect seasonal recreational vessel traffic patterns. Overall, our GAMs explained 20-37 % of all vessel traffic during the summer and winter, and highlighted subregions where vessel traffic is under represented by AIS.
... Small recreational boats are highly popular in coastal areas, and can cause an array of ecologically destructive effects, but monitoring their impacts is challenging (Hawkins et al., 2015;Hermannsen et al., 2019;Whitfield and Becker, 2014). Sound emitted by small boats, a form of anthrophony (human-generated sound), is highly variable (Parsons et al., 2021) with the capacity to elevate and transform the characteristics of shallow coastal soundscapes (Buscaino et al., 2016;Dinh et al., 2018;Kaplan and Mooney, 2015;Pine et al., 2021). ...
Article
Small recreational boats are an omnipresent source of sound pollution in shallow coastal habitats, which can impact the behavior and physiology of a wide array of taxa. However, effective monitoring of this stressor is currently limited by a lack of tools. The present study coupled passive acoustic monitoring (PAM) with timelapse imagery to provide a comprehensive analysis of sound pollution at two coastal sites varying in habitat structure: Goat (rocky reef) and Kawau (sandy bay) Islands. A convolutional neural network (CNN) was used to automatically count boats in each image, and the relationship between the soundscape and number of boats present was analysed using power spectral density and adaptive threshold analyses. Small boat activity was positively correlated with third octave level (TOL) root mean squared sound pressure levels (SPLRMS 63 – 5011 Hz), and this effect was frequency dependent, at both Goat (F7,9704 = 5.665, p < 0.001) and Kawau (F7,42488 = 325.33, p < 0.001) Islands. However, at Goat Island this interaction effect was driven by a significant difference between 63 Hz and all other TOLs (p < 0.05), whereas at Kawau Island the interaction effect of TOL and boat number was more variable. Furthermore, low frequency (∼50 – 300 Hz) biophony was found to influence the likelihood of boat sound being detected at Goat Island. Small boat impacts are contextual, likely due to habitat specific propagation conditions and the presence/absence of vocalising animals. As such, monitoring of sound pollution in coastal habitats requires a tailored approach which accounts for the localised nature of shallow coastal soundscapes. These findings demonstrate the potential for timelapse imagery to elucidate variability in boat sound, which may be particularly useful for remote sites which are ecologically rich, yet have no acoustic protections, such as many marine protected areas.
... Building inland waterways affects many components of river ecosystems [1,2] because of the inevitable anthropogenic interventions, such as regulating river channels, constructing dams, dredging channels, and building wharves [3][4][5][6]. Stream channels and riparian zones are affected by building and operating inland waterways [7,8], resulting in changes in dissolved and suspended nutrients, substrate composition, sediment deposition, and the abundance of aquatic organisms within specific stretches of the rivers [9,10]. Habitats within natural riparian zones are also heavily impacted when inland waterways are built in mountainous regions [11][12][13][14]. ...
Article
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Building inland waterways affects the natural structure, formation, and extent of the riverbed and riparian zone. It alters the hydrology and sediment deposition conditions and hence damages the aquatic ecosystem. To address the effects of the construction of inland waterways on the riverine biome, benthic macroinvertebrate communities were compared at different building stages of inland waterways along a gradient of shipping traffic density at two montane rivers in China. The Shannon–Wiener diversity index of the benthic macroinvertebrate communities ranged from 0.4 to 1.6; the lowest value was recorded in the completed inland waterway, while the highest value was recorded in the unaffected stretch. Principal component analysis and canonical correlation analysis showed the communities in the inland waterways to be distinct from those in the natural riparian habitats. Our results suggest that benthic macroinvertebrate communities can reflect the damage done by the hydromorphological modifications caused by building inland waterways. Benthic macroinvertebrate diversity and abundance should therefore be included when assessing the impact of building and operating inland waterways.
... Scar areas also support lower macrofaunal abundance and diversity relative to SAV (Uhrin and Holmquist 2003). In addition to SAV impacts, turbidity generated by propellers can disrupt or even bury newly settled shellfish (MacFarlane 1996) and finfish eggs (Whitfield and Becker 2014). ...
Article
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Small docks and floats are common in estuaries and coastal waters worldwide. These structures serve a role in coastal recreation by facilitating access to waterways. However, they can impact shoreline ecological function. While individual environmental impacts are generally minor, increasing dock proliferation and overlap with sensitive coastal resources can result in cumulative impacts that pose threats at the ecosystem level. Docks promote changes in habitat and aquatic communities through alteration of environmental conditions. Here, we review the potential environmental impacts of docks on estuarine and coastal flora and fauna and discuss best management practices (BMPs) to avoid or minimize such impacts with a focus on New England. We consider impacts in relation to the structural components of docks: the piles, decking, and floats. Impacts to salt marsh and submerged aquatic vegetation are a particular focus given the important ecosystem services these vegetated habitats provide and their vulnerability to dock-induced habitat alteration. Potential environmental impacts depend on structure size, design, and location, and can include both short-term (e.g., turbidity from pile installation) and long-term (e.g., salt marsh loss from chronic shading) effects. Such effects can be minimized through BMPs (e.g., construction outside sensitive time-of-year periods, designs to reduce shading). As BMPs tend to reduce rather than avoid environmental effects, cumulative impacts also need to be considered in the permitting process. We recommend that managers develop plans or bylaws that identify sensitive habitats where dock construction should be avoided as well as BMPs to make remaining dock proliferation less impactful.
... Loes fishers also expressed concern about the impacts of larger-scale, less selective fishing gear now being used in neighboring communities. Detrimental impacts on fish populations have been shown to result from noise disturbance and pollution from small motor boats (Whitfield and Becker, 2014). However, while plastic ingestion by marine fish, including those of commercial importance, is increasing globally, there is no evidence as yet of negative effects on fish populations (Lusher et al., 2017;Savoca et al., 2021). ...
Article
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Tropical sardines (Family Clupeidae) are an important component of many marine fisheries in the Indo-West Pacific region. In Timor-Leste, a small, less-developed country within this region, ‘sardiña’ are some of the more commonly caught and consumed fish. Yet there is little published information from Timor-Leste about the species composition of these fisheries, nor their biology or ecology. We document the knowledge of Timorese fishers on nine locally distinguished sardine types that contribute to fisheries, and relate these to at least nine species: four species of ‘Flat-bodied Sardinellas’ (Sardinella subg. Clupeonia spp.), one species of ‘Round-bodied Sardinella’ (Sardinella subg. Sardinella lemuru), two species of ‘Tropical Pilchards’ (Amblygaster spp.) and a ‘Tropical Herring’ species (Herklotsichthys quadrimaculatus), all from the Clupeidae family; and one Dussumieria species from the Dussumieriidae family. We record variations in local sardine names across the country and document aspects of fishers’ knowledge relevant to understanding and managing the fisheries, including local sardine species’ seasonality, habitat, movements, interannual variation, as well as post-harvest characteristics in relation to perishability. In general, local names relate more closely with groups of species than individual species, although some names also distinguish fish size within species-groups. The local knowledge identified in this study has immediate application to inform fisheries monitoring and management, and to identify areas for future research. Notably, Timorese fishers recognize and make use of the strong association between some sardine species-groups and seasonally turbid river plumes. While further research is required to understand the underlying mechanisms of this association, this emphasizes the need to consider coastal fisheries and fisher livelihood impacts when assessing any plans or proposals that may alter river flow or water quality. Fishers also recognize migratory behavior of some sardine species, in particular the Flat bodied Sardinellas (S. gibbosa and others) along the north-west coast of Timor-Leste and across the border into Indonesian West Timor. Such insights complicate and need to be accounted for in initiatives for co-management or community-based management of Timor-Leste’s coastal waters and their fisheries.
... The resuspension of sediments (Houser 2011) can increase nutrient loadings, which in turn can promote algal growth and reduce light penetration (Mosisch andArthington 1998, Eriksson et al. 2004), as well as alter planktonic behavior (Waggett and Buskey 2007) and trophic interactions (Marass e et al. 1990, MacKenzie andLeggett 1991). Boat wakes may also enhance vertical mixing within the water column (Fugate and Friedrichs 2003) and present a wide array of stressors to aquatic organisms, including noise (Mickle et al. 2019), chemical pollutants (Whitfield and Becker 2014), and direct physical harm . ...
Article
Houser C, Smith A, Lilly J. 2021. Relative importance of recreational boat wakes on an inland lake. Lake Reserv Manage. XX:XX–XX. Wakes generated by recreational boats have the potential to erode the shoreline, damage infrastructure, or disrupt aquatic ecosystems. Therefore, boat wakes are an increasingly important focus of coastal management, particularly along vulnerable shorelines. This short communication quantifies the relative importance of recreational boat wake energy along the shoreline of an inland cottage lake in Northern Ontario, Canada. Measurements of recreational boat wakes at the end of one of the longest fetches for locally generated wind waves on the lake account for >61% of total wave energy. Based on this result, recreational wake energy likely is the primary source of wave activity along sections of the lake adjacent to the primary sailing lines but not aligned to the primary directions of wind wave energy. Recreational boat wakes may be a significant source of wave energy on other inland lakes.
... Yet, most of the research on noise pollution on coral reefs (95% of papers) concerns noise originating from vessels. Moreover, research has focused on 2-stroke engines, which produce power in 2 cycles and are commonly equipped to small boats owing to their ease of usage, particularly in shallow waters (Whitfield and Becker, 2014). Only very few recent studies (ca. 4 out of a mean of 25 studies) investigated 4stroke engines, employed most often by large ships or fishing vessels, which are quieter, i.e., produce noise at lower intensities, than 2-stroke engines (McCormick et al., 2018b;McCormick et al., 2019). ...
Article
Noise pollution is an anthropogenic stressor that is increasingly recognized for its negative impact on the physiology, behavior and fitness of marine organisms. Driven by the recent expansion of maritime shipping, artisanal fishing and tourism (e.g., motorboats used for recreational purpose), underwater noise increased greatly on coral reefs. In this review, we first provide an overview on how reef organisms sense and use sound. Thereafter we review the current knowledge on how underwater noise affects different reef organisms. Although the majority of available examples are limited to few fish species, we emphasize how the impact of noise differs based on an organisms' acoustic sensitivity, mobility and developmental stage, as well as between noise type, source and duration. Finally, we highlight measures available to governments, the shipping industry and individual users and provide directions for polices and research aimed to manage this global issue of noise emission on coral reefs.
... Besides a signi cant increase in overall sound levels, anthropogenic noise sources add new sounds into the environment that differ greatly in spectral composition and duty cycle from the natural soundscapes 7,8 . For instance, shipping and recreational boats add a broadband noise component into the overall aquatic acoustic scene that lasts much longer compared to pile driving and seismic air guns that generate impulsive short-lasting low frequency sounds 9,10 . ...
Preprint
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Noise pollution is increasingly present in aquatic ecosystems, causing detrimental effects on growth, physiology and behaviour of organisms. However, limited information exists on how this stressor affects animals in early ontogeny, a critical period for development and establishment of phenotypic traits. We tested the effects of chronic noise exposure to increasing levels (130 and 150 dB re 1 μPa, continuous white noise) and different temporal regimes on larval zebrafish (Danio rerio), an important vertebrate model in ecotoxicology. The acoustic treatments did not affect general development or hatching but higher noise levels led to increased mortality. The cardiac rate, yolk sac consumption and cortisol levels increased significantly with increasing noise level at both 3 and 5 dpf (days post fertilization). Variation in noise temporal patterns (different random noise periods to simulate shipping activity) suggested that time regime adopted is more important than the total duration of noise exposure is important to down-regulate physiological stress. Moreover, 5 dpf larvae exposed to 150 dB continuous noise displayed increased dark avoidance in anxiety-related dark/light preference test and impaired spontaneous alternation behaviour. We provide first evidence of noise-induced physiological stress and behavioural disturbance in larval zebrafish, showing that both noise amplitude and timing negatively impact key developmental endpoints in early ontogeny.
... The wave energy generated by a turning vessel is also intensified on the inside of the turn and spread on the outside (Macfarlane et al., 2014), a phenomenon which may contribute to the erosion observed on the inside of meander bends. The reported longer-term impacts of boat wash erosion include the abrasion of bank material, severe undercutting, slumping, bank slips, and cantilever failure (Bhowmik, Soong, Reichelt, & Seddik, 1991;Bradbury, Cullen, Dixon, & Pemberton, 1995), impacts on biota (e.g., Whitfield & Becker, 2014) and instream vegetation (e.g., Asplund & Cook, 1997). ...
Article
Macrotidal tropical rivers are dynamic systems where wet-season floods and tidal flows cause significant riverbank erosion and sediment transport. This study aimed to explore patterns of riverbank erosion and deposition in a large, tropical, macrotidal river in Northern Australia; the Daly River. In particular, we aimed to determine if recreational boat use was impacting bank erosion in this dynamic river. Erosion pins were installed at multiple levels on both banks at 10 sites along a 34 km reach of the river. Measurements were made every four to six weeks during the low water dry season, and opportunistically during the wet season (flooding period) and seasonal transition periods. A bank geotechnical assessment, riverbed cross-sections and site bathymetry were undertaken. Whilst the wet season was a period of substantial erosion (mean rate of 0.64 mm day−1), the highest mean erosion rate (3.6 mm day−1) was observed in the early dry season (April to May), a period of stabilizing water levels but greatest boat traffic. Bank erosion at this time was measured on both sides of the river and the inside of meander bends, which is atypical of normal riverine bank erosion patterns, and indicative of erosion due to boat wash. As the dry season progressed, significant spatial differences in erosion rates were evident, where erosion was observed at sites upstream of a large shallow sand bar, while sites downstream from the sand bar gained material through the deposition of tidally transported sediment. This study highlights the importance of understanding the significance and interaction of various erosive factors in tropical tidal rivers and has demonstrated that boat wash may be an important contributor to dry season bank erosion in these systems. We encourage management agencies to consider the role of boats in any future river management program in these systems.
... The main pollution sources from recreational boating are fuel, oil and other chemicals discharged from powered boats (Burgin and Hardiman, 2011). These pollutants can be discharged due to engine activities, affecting species present in the ecosystem (Whitfield and Becker, 2014) but also by dilution from antifouling paints employed on ship hulls to prevent fouling by marine organisms (Schiff et al., 2004). Actually, as these treatments contain toxic chemicals for some organisms, they also have an effect against biological invasions via recreational boating, which has been classified as an important vector for secondary dispersal of non-indigenous and invasive species (Clarke Murray et al., 2011;Drake et al., 2017). ...
Article
Recreational ports are known to be sources of pollution to the coastal marine environment due to the pouring of pollutants or the transfer of invasive species to neighboring areas. Nonetheless, the responsibility of protecting the marine environment does not lie solely on the users of the ports, but also affects the rest of citizens. Thus, an effective communication is necessary between scientists and citizens to avoid the lack of knowledge and boost cooperation against these environmental problems. In this study, (focused on the marina of Gijon, Northwestern Spain) citizens set education and social media as the main sources of information, rarely considering science outreach. Also, their environmental knowledge showed to be based on a visual perception, rather than on a cognitive one, as marine litter was considered a great environmental problem, while invasive species and biofouling went unnoticed, remarking the lack of an effective communication from scientific sources.
... Boating activity can also have a variety of social, cultural, and ecological impacts (Burgin and Hardiman, 2011;Lloret, 2011). Ecological impacts arise from anchor damage, pollution from waste discharge (Grigg, 1994) and anti-fouling paint (Carbery et al., 2006), littering (Abu-Hilal and Al-Najjar, 2004), increased turbidity and erosion (Liddle and Scorgie, 1980), sound (González Correa et al., 2019;Whitfield and Becker, 2014), spread of invasive species (West et al., 2007), and vessels striking animals (Kemper et al., 2005). Successful management of increasing levels of boat activity, therefore, requires understanding the spatial and temporal occurrence of these impacts and how they are influenced by alternate management tools. ...
Article
Recreational boating is increasingly popular and provides social and economic benefits, but can also have ecological impacts, including damage from anchoring on sensitive seabed habitats like coral reefs. Mooring buoys are commonly used to manage anchoring activity, and I tested whether they moderated anchoring on coral reefs in the British Virgin Islands. A spatial survey revealed that overall boat use (moored plus anchored) was 3.6 times higher at sites with moorings than those without. The density of boats anchored on coral reef was, however, reduced by roughly half at sites with moorings. A survey of two sites before and after moorings were installed confirmed that the addition of moorings increased the total number of boats at a site, but reduced the rate of anchoring on reef. At any given site, the rate of anchoring on reef increased as the total number of boats present increased, but the effect of crowding was diminished at sites with moorings. Moorings can thus be an effective management tool for mitigating anchor damage to sensitive habitats, and because boat densities continue to rise worldwide, these findings focus attention on discovering why moorings reduce the tendency of boats to anchor on reef as sites become more crowded.
... The level of noise in the sea has been linked to the global economy (Frisk, 2012), whereby shipping constitutes 90% of the method of trade between different countries, and it is certain to continue to increase as the ocean becomes more industrialized. Many excellent reviews exist on the effects of aquatic noise on marine mammals, bony fishes and invertebrates (Nowacek et al., 2007;Weilgart, 2007;Popper and Hastings, 2009;Slabbekoorn et al., 2010;Hawkins and Popper, 2014;Hawkins et al., 2014a,b;Radford et al., 2014;Whitfield and Becker, 2014;Braun, 2015;Peng et al., 2015;Williams et al., 2015;Zakon, 2015;de Soto, 2016;de Soto and Kight, 2016;Gomez et al., 2016;Kunc et al., 2016;Juanes et al., 2017), so the following information represents only a short synopsis. ...
Book
Many sensory systems are more commonly known than others, but all are critical for survival. These include those senses typically described by Aristotle around 300–400 Before the Common Era (BCE), such as sight (vision), hearing (audition), touch (somatosensation), smell (olfaction), and taste (gustation). However, many years of scientific endeavor have shown that these five senses represent only a part of the sensory abilities that are now known throughout the aquatic animal kingdom. The extended repertoire of senses includes the ability for vestibular control (equilibrioception), the sensation of temperature (thermoreception), postural awareness (proprioception), the monitoring of pain (nociception), the use of sonar (echolocation), and the detection of weak electric (electroreception) and magnetic (magnetoreception) fields. The papers presented in this Research Topic were greatly welcomed and consist of a collection of exciting and well-received articles that incorporated new knowledge on almost all of the known senses in a range of aquatic vertebrates, such as the sarcopterygian lungfishes, both freshwater and marine teleosts, elasmobranchs, marine reptiles, and cetaceans (marine mammals). The papers target many of the known senses in aquatic vertebrates, but are biased toward vision, which reflects the number of active research programs that concentrate on this sensory modality.
... Plumbum is used in many different ways, for example, it is used to produce batteries, ammunition, metal products such as solder and pipes and X-ray shielding devices, resulting in related health concerns; consequently, its usage has been drastically reduced in recent years. Similarly, the high concentration of lead at study area was situated at the boat stations where high boating activities take place and where the pH of the sediment was the lowest (Whitfield and Becker, 2014). While, drinking water major source of lead in human body cause containing substantial amount of lead which is initially it can enter the body through the digestive tract and lungs and carried spread by blood throughout the body. ...
Article
Purpose This study aims to examine the metal pollution in coastal sediment in the Peninsular Malaysia. Design/methodology/approach Approximately 141 published studies were screened from 1,285 documents and reviewed to determine the existing pollution status in the coastal areas of Peninsular Malaysia and the metals under review were Pb, Hg, Cd, Ar, Cu, Zn, Cr and Ni. Sources of pollutants and their effect on biological systems, marine organisms and human health were addressed in this review as well as recommendation of heavy metal removal or remedies in short. Emphasis is placed on marine pollution, particularly on the toxic metal accumulation in biota. Findings This study has revealed the different concentrations of pollutants, low, moderately, and chronically contaminated areas from heavy metals and the consequences to aquatic ecosystem and indirectly to human health, since an increasing in the coastal developments in Peninsular Malaysia. Originality/value This study has revealed the different concentrations of pollutants, low, moderately, and chronically contaminated areas from heavy metals and the consequences to aquatic ecosystem and indirectly to human health, since an increasing in the coastal developments in Peninsular Malaysia.
... Motorboat noise can also affect fish physiology, individual fitness, behavior, and population in the coral reef environment (Simpson et al., 2016;McCormick et al., 2018). Boat generated waves, chemical pollutants such as heavy metal, petroleum hydrocarbons, and antifouling paints further impact coral habitat negatively (Whitfield and Becker, 2014). Furthermore, boats and divers increase sediment resuspension, wastewater, nutrient discharge, and shoreline erosion (Hawkins et al., 1999;Lamb et al., 2014). ...
Article
Globally, coral reefs have drastically declined due to local and global environmental stressors. Concurrently, coral reef tourism is rapidly growing in developing economies, which is one of many anthropogenic stressors impacting reefs. At the Malvan Marine Sanctuary, a Marine Protected Area (MPA) on the West coast of India, we investigate the impact of recreational diving on the reef from 2016 to 2019. To evaluate the diver’s underwater behavior, a novel approach was used, wherein the video-log broadcasting website www.youtube.com was perused. Evidential proof substantiates heavy physical damage to corals because of recreational diving activity, which may lead to the collapse of coral habitat if it continues unabated. This resource depletion ironically elevates the economy of dependents averting consequences due to lost corals, thus making this a ‘tragedy’ for corals which are not meant to be ‘commons’. The study asserts need for proactive conservation efforts with stringent implementation and restoration initiatives in this MPA.
... Habituation of fish to artificial feeding can lead to the dominance of a few species and a long-term reduction of taxonomic richness (Medeiros et al., 2007). At several tourism feeding sites, fish also anticipate feeding events and congregate in response to the noise of boat engines (Newsome et al., 2004, reviewed by Whitfield andBecker, 2014). Although arguably possible, it is unlikely that the differences observed here between tourism and experimental feeding sites are confounded by fish moving across sites. ...
Article
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Feeding wild animals is a regular habit in ecotourism worldwide with poorly known consequences for ecosystem functioning. This study investigates how effective bread feeding is at attracting coral reef fish in the South Pacific, which feeding groups of fish are most attracted, and how natural foraging rates of an omnivorous and a grazing-detritivorous fish are affected. Data were collected at sites where fish are regularly fed bread by snorkellers and at comparison sites where bread was only provided for this study, within the Aitutaki lagoon (Cook Islands). The fish community was censused and foraging rates of two model species (Chaetodon auriga, Ctenochaetus striatus) were quantified one hour before, during, and an hour after feeding events. Twenty-five percent of the species present at all sites (piscivores-invertivores) were effectively attracted to bread. Overall, mean fish density was higher at tourism feeding sites than at the comparison sites. During bread feeding events, taxonomic richness decreased, compared to the hours prior and after feeding across all sites. As piscivore-invertivores were consistently attracted to bread, localized shifts in their dominance over other trophic groups may be expected if bread feeding persists, likely carrying consequences for ecosystem functioning. The effect of bread feeding events on natural foraging rates differed between the model species. C. auriga ceased foraging on natural foods to feed on bread. Although C. striatus never fed on bread, its foraging rate on epilithic algal matrices decreased during bread feeding events. This indirect non-lethal ecological consequence of bread feeding contributes a previously unanticipated example relevant to the “ecology of fear” in marine fish. Stakeholder interviews revealed that locals favor feeding to sustain tourist satisfaction, whereas tourists appreciate snorkeling regardless of feeding. This indicates an opportunity for restrictions on fish feeding with minimal drawbacks for tourism. Future research on fish metabolism and cascading effects on the reef benthos may reveal further impacts of feeding on coral reef communities.
... Coastal and offshore human activities often lead to local increments of ambient noise levels, polluting the marine soundscape (Slabbekoorn et al. 2010;Radford et al. 2014;Whitfield & Becker 2014;Dooling et al. 2015;Hawkins & Popper 2018;Putland et al. 2018). To better understand the short and long-term effects of marine acoustic pollution, not only at the individual but also at the population and ecosystem level (Kunc et al. 2016;Nabe-Nielsen et al. 2018), more underwater acoustic ecological studies should be performed (Slabbekoorn et al. 2010;Brumm 2014;Radford et al. 2014;Slabbekoorn 2016). ...
Article
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The deleterious effects of anthropogenic noise on animal communication are nowadays recognised, not only in urban environments but also in terrestrial habitats and along coasts and in open waters. Yet, the assessment of short- and long-term exposure consequences of anthropogenic noise in marine organisms remains challenging, especially in fish and invertebrates. Males of the Mediterranean damselfish Chromis chromis vocalise and perform visual displays (multimodal communication) to attract mates. The frequency-range of courtship vocalisations overlaps with low-frequency noise generated by maritime activities, resulting in a reduced detection distance among conspecifics. We quantified the number of courtship-related visual displays performed by males living in areas with different levels of maritime traffic. We also tried to manipulate ambient noise in the field to test male short-term response to increased noise levels. Males living in busier areas (near to a harbour) performed significantly more visual displays than those living in less congested areas. When exposed to artificially-increased ambient noise level (playback of boat noise), males did not adjust the number of visual displays accordingly. Yet, we note how assessing the actual effect of maritime traffic in marine populations in their natural environments is particularly difficult, as the effects of boat noise cannot be easily disentangled from a variety of other intrinsic or environmental factors, discussed in the paper. We thus present suggestions to obtain more robust analyses of variations of courtship behaviours in territorial fishes. We hope this will facilitate a further understanding of the potential long-term effects of anthropogenic noise, whose analyses should be prioritised in the context of environmental impact assessment, resource management and biodiversity conservation.
Article
Recreational fisheries represent a pivotal leisure industry in most countries with coastlines, making substantial contributions to economic growth and social welfare. Spatial spillover effects remain less well explored in the existing research on the sustainability of recreational fisheries. In this study, we develop a framework to assess the sustainability of recreational fisheries across the coast of China from 2010 to 2019. We examine the driving factors and mechanisms sustaining recreational fisheries using a spatial Durbin model. The results reveal an overall upward trend in the sustainability index of China's coastal recreational fisheries, with several notable regional differences. Furthermore, we found that recreational fishery sustainability exhibited spatial dependency across coastal provinces. The sustainability was influenced by both local factors and spillover effects from neighboring regions. The local factors ranked in order by direct effect coefficients from highest to lowest were consumption capability, travel convenience, policy, fishery management, urbanization, and environment. Indirect effect coefficients indicated that the degree of travel convenience and fishery development of neighboring regions had positive spillover effects, whereas consumption capability and tourism had negative effects. These findings offer new insights into the mechanisms influencing recreational fishery sustainability, information that is vital for effective coastal management and the sustainable development of recreational fisheries.
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Planning for effective conservation demands an accurate understanding of the ecological aspects of species, particularly their distribution and habitat preferences. This is even more critical in the case of data-poor, rare, and threatened species, such as seahorses, mainly when they inhabit vulnerable ecosystems like estuaries. Given the importance of better understanding these parameters to design seahorse conservation strategies, we mapped the distribution and assessed habitat preferences of longsnout seahorses (Hippocampus reidi) in a mangrove estuary in a Brazilian protected area. Using generalised linear mixed-effects models we found that dense mangrove cover macro-habitats and shallow depths predicted seahorse sightings and higher densities. Furthermore, the selective index of micro-habitats used by seahorses showed that seahorses exhibited a preference for mangrove structures as holdfasts (i.e., fallen branches). Due to the significant importance of mangroves in providing suitable habitats for H. reidi in estuaries, it is crucial to enforce the protection of these ecosystems in conservation and management strategies for the species.
Article
The impacts of recreational boating on lake ecosystems are often not well characterized, including for Lake Champlain (US/Canada) where excess watershed phosphorus loading drives cyanobacteria blooms. Improperly disposed boater-generated sewage has not been considered as a source of phosphorus in total maximum daily load models or implementation plans for the Lake. Surveys of marinas and boaters informed sewage production estimates by marina-using boaters. Annual boater-generated sewage volume was estimated to range between 2,445 and 5,184 m³. These volumes allowed estimation of potential phosphorus contributions to Lake Champlain by improperly disposed sewage at varied rates of discharge. Such contributions were negligible compared to known Lake Champlain phosphorus sources, suggesting use of Clean Water Funds to reduce phosphorus inputs may not be warranted. Nonetheless, due to potential for pathogen contamination, continued financial support through other means was recommended to allow marinas to operate and maintain pumpout facilities at rates reasonable to boaters. Management implications Improperly disposed sewage was estimated to represent <0.01% of annual phosphorus contributions to Lake Champlain (USA/Canada). As such, Clean Water Funds targeted to address significant phosphorus inputs to the lake may not be warranted. Nonetheless, continued governmental support for marinas to provide and maintain sewage pumpout facilities for free or at rates most boaters were willing to pay is recommended to minimize introduction of pathogens associated with fecal pollution. To further help ensure compliance with sewage disposal regulations, educational materials and messaging to boaters to encourage use of pumpout facilities should be made available in English and French due to significant populations of boaters speaking each language.
Chapter
Recurrent landscape patterns occur around the world. Some of these are particularly important because they are strictly connected with human life and habits (e.g., urban landscapes, farming landscapes, cultural landscapes, etc.). Urban landscapes concentrate the majority of benefits that human culture and technology have achieved along with the history of human civilization. Energy, trends, threats, and level of sustainability are some of the fundamentals considered in the urban landscape. The farming landscape is the food source for the entire human population and in particular for the urban dwellers. The farming activity can be distinct in an industrialized regime that produces food for a great mass of (urban) people and a low-intensity activity still connected to old farming uses and practices. Japanese Satoyama and Montado of Iberian peninsula are selected examples of traditional land use in cultural landscape. Tropical agroforestry systems for the production of cacao and coffee contrast with industrialized systems like palm oil plantations and extensive deforestation for cattle ranching. Landscape ecology helps to sustain traditional farming systems and to guide urban development with the goal to maintain biodiversity and healthy human conditions, integrating information from freshwater landscapes, mining and energy landscapes, hybrid landscapes, and therapeutic landscapes.
Technical Report
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Many people and societies, in Sweden as well as globally, receive great joy and benefits from shallow coastal waters and their ecosystems. Several types of human activities concurrently and continuously affect these ecosystems. The physical activities affecting coastal ecosystems include coastal exploitation, marine production of energy, extraction of living and non-living resources, cultivation of living resources, transport, marine tourism and leisure, security and defence, etcetera. These activities are leading to typical pressures on the coastal environment as loss of or disturbance of benthic habitats, changes in turbidity, smothering, littering, electromagnetic changes, noise changes, light changes, introduction of barriers for species movement, contact/collision, visual disturbance, but also hydrographical, chemical and biological changes. Through the use of the DPSIR-framework, this report provides a broad overview of the main human physical activities and their effects on coastal ecosystems, with a particular focus on Swedish conditions. In addition, the report analyses biological effects, state changes, exerted by physical activities on coastal ecosystems, and how sensitive different types of key habitats and ecosystem components are to the main physical activities, and what consequences this may have for marine ecosystem services. The analyses are both descriptive and quantitative. Relationships between activities and pressures, between activities and ecosystem components, between activities and habitats, between activities and ecosystem services, between pressures and the sensitivities of important habitats are presented in separate appendices. It is also presented which water depths and which sea areas that are especially affected by certain physical activities, which physical activities that can have cumulative impact with other physical activities on the environment as well as which physical activities that can have cumulative impact on the environment with different non-physical pressures. Hopefully, the report can broaden the understanding of the structure and function of coastal ecosystems and the physical pressures affecting them. Moreover, the analysis may form the basis for identifying and strengthening a functional marine green infrastructure, as well as for physical planning and ecosystem-based management.
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Noise pollution is increasingly present in aquatic ecosystems, causing detrimental effects on growth, physiology and behaviour of organisms. However, limited information exists on how this stressor affects animals in early ontogeny, a critical period for development and establishment of phenotypic traits. We tested the effects of chronic noise exposure to increasing levels (130 and 150 dB re 1 μPa, continuous white noise) and different temporal regimes on larval zebrafish ( Danio rerio ), an important vertebrate model in ecotoxicology. The acoustic treatments did not affect general development or hatching but higher noise levels led to increased mortality. The cardiac rate, yolk sac consumption and cortisol levels increased significantly with increasing noise level at both 3 and 5 dpf (days post fertilization). Variation in noise temporal patterns (different random noise periods to simulate shipping activity) suggested that the time regime is more important than the total duration of noise exposure to down-regulate physiological stress. Moreover, 5 dpf larvae exposed to 150 dB continuous noise displayed increased dark avoidance in anxiety-related dark/light preference test and impaired spontaneous alternation behaviour. We provide first evidence of noise-induced physiological stress and behavioural disturbance in larval zebrafish, showing that both noise amplitude and timing negatively impact key developmental endpoints in early ontogeny.
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Fisheries and urban marine ecology meet within the world’s densely populated estuaries and coasts, where the imperative of dredging, construction and catchment modification occurs alongside the socio-economic characteristics of urban communities. Estuarine fisheries in urban areas have often shifted away from commercial harvest towards recreational fishing, fuelled by a diverse range of motivational factors. These systems are thus often dominated by recreational and subsistence fisheries, with the fisheries system variously impacted by eutrophication, contamination and pollution, altered trophic structure, habitat loss and hard structure. Urban marine ecosystems may be distinguished by the absence of spawning by exploited finfish, coupled with the gradual loss of environmental signals for recruitment, reduced larval supply and loss of nursery habitats for juveniles, but alongside an abundance of hard structure habitats for adults. The shift from commercial fishing to preferential harvest of more predatory “sportfish” means that the historical trophic structure has shifted towards lower trophic levels (e.g. prawns, detritivores, planktivores). We outline urban estuarine fisheries ecology as a developing paradigm defined by the unique ecological attributes of urbanised estuaries, the socio-economic objectives of fishers therein, and bottlenecks to productivity of the species they exploit. We identify goals for future research and management and illustrate these concepts through discussion of stock enhancement with a large estuarine predatory fish.
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Biosemiotics to date has focused on the exchange of signals between organisms, in line with bioacoustics; consideration of the wider acoustic environment as a semiotic medium is under-developed. The nascent discipline of ecoacoustics, that investigates the role of environmental sound in ecological processes and dynamics, fills this gap. In this paper we introduce key ecoacoustic terminology and concepts in order to highlight the value of ecoacoustics as a discipline in which to conceptualise and study intra- and interspecies semiosis. We stress the inherently subjective nature of all sensory scapes (vivo-, land-, vibro- and soundscapes) and propose that they should always bear an organismic attribution. Key terms to describe the sources (geophony, biophony, anthropophony, technophony) and scales (sonotopes, soundtopes, sonotones) of soundscapes are described. We introduce epithets for soundscapes to point to the degree to which the global environment is implicated in semiosis (latent, sensed and interpreted soundscapes); terms for describing key ecological structures and processes (acoustic community, acoustic habitat, ecoacoustic events) and examples of ecoacoustic events (choruses and noise) are described. The acoustic eco-field is recognized as the semiotic model that enables soniferous species to intercept core resources like food, safety and roosting places. We note that whilst ecoacoustics to date has focused on the critical task of the development of metrics for application in conservation and biodiversity assessment, these can be enriched by advancing conceptual and theoretical foundations. Finally, the mutual value of integrating ecoacoustic and biosemiotics perspectives is considered.
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Keywords: anthropogenic noise bioacoustics community effect foraging behaviour freshwater fish sensory ecology species dependence Anthropogenic noise is globally increasing in aquatic ecosystems and causes adverse repercussions in many fish species, yet its effect on freshwater fish is not well understood. Here, we test the impact of boat noise on foraging and swimming behaviour on a number of wild freshwater fish species as well as captive black bullhead, Ameiurus melas, a common species in the Laurentian Great Lakes with known hearing specializations. In a laboratory setting, black bullhead were exposed to white noise, boat noise and a quiet control and monitored for changes in foraging behaviours and swimming patterns when presented with food. Black bullhead exposed to both boat noise and white noise foraged less and startled more in comparison to trials without noise. In a field setting, wild fishes with differing hearing capabilities were exposed to boat noise and a quiet control, then analysed for changes in both presence and foraging behaviour when presented with food. Field experiments were consistent with results from our laboratory study, resulting in decreased presence of wild fish and fewer foraging attempts made during boat noise exposure. However, the effects of noise in the field were highly variable by family, with fish in the Cyprinidae (or Leuciscidae) family, all of which have Weberian ossicle hearing specializations, exhibiting significantly larger decreases in feeding events and presence compared to other families (Gobiidae, Percidae and Centrarchidae) with more basic hearing abilities. Freshwater fishes alter their foraging behaviour during noise exposure, however, variation in hearing abilities may determine the extent to which their behaviour changes and the resulting degree of negative consequences.
Technical Report
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Green infrastructure (GI) is a concept that has, in recent years, become established within nature conservation and is an important part of Sweden’s work within biodiversity and ecosystem services. The Swedish Environmental Protection Agency defines green infrastructure as “an ecologically functional network of habitats and structures, natural areas and landscaped elements that are designed, used and managed in a way that preserves biodiversity and promotes important ecosystem services throughout the landscape”. IMAGINE has focused on how management strategies can strengthen and support the preservation of green infrastructure in the marine environment. The need to promote an ecosystem-based approach and a landscape perspective in the management of marine ecosystems is primarily expressed in international and EU law. However, in general, the requirements laid down in international law are vaguely formulated. Moreover, the enforcement mechanisms available under EU law are lacking. While EU law provides both sharper obligations and enforcement mechanisms, there is no explicit legal requirement to preserve a marine green infrastructure or to take measure to ensure that the network of protected areas becomes coherent and representative. The Habitats Directive, however, provides strong protection of designated species and habitats through the establishment of Natura 2000 areas and Member States can be obliged to take connectivity measures also outside protected areas, if this is necessary for the conservation of the species and habitats within a Natura 2000-site. The Marine Strategy Framework Directive moreover requires that the programmes of measures specify measures needed to ensure a coherent and representative network of marine protection areas, but there is no clear definition of those concepts. All in all, the directives provide little guidance on how to include a landscape perspective in practice. National law allows for the protection of green infrastructure, including the establishment of protected areas, however, even in this case there is no requirement to apply an ecosystem approach or a landscape perspective in the decision-making. Environmental quality standards for good ecological status and environmental status, which also applies outside protected areas, are important tools for protecting green infrastructure. However, there is a risk of a lack of application of the standards in relation to activities that are not subject to a permit requirement under the Environmental Code. It is therefore important that the standards are applied to other decisions under the Code, but also under other legislative acts (such as fishery legislation) and that cumulative effects are taken into account. Spatial planning is one instrument that can be used to enable a holistic approach in management of marine ecosystems, and thus to preserve and restore marine green infrastructure. However, the current regulations for marine spatial planning lack clear guidance towards conservation or restoration of a green infrastructure in Swedish marine waters. Although there is a requirement to apply an ecosystem approach in the national marine planning, there is no definition of an ecosystem approach and no clear guidance on how to develop plans to achieve environmental objectives. While a good environmental status is one of the, potentially conflicting, objectives to be achieved, it is not clearly stated that this is an overarching objective. Unlike the national planning, there is no requirement for an ecosystem approach to be applied in municipal planning. The regional action plans for green infrastructure from the County Administrative Boards could be an important tool to bridge the gap between national and municipal planning and integrating the management of land and terrestrial ecosystems, if they are integrated in the legal system. Different parts of the process need different approaches. Within IMAGINE we used spatial modelling to map ecosystem components and connectivity. In the light of DPSIR and MOSAIC, we have implemented scenario-based impact analysis, identification and prioritization of core areas and coherent networks, together with analyses of the regional action plans for green infrastructure and municipal planning. We also reviewed the legal governance of green infrastructure, both in general and in the light of our case studies. Scenario-based impact analysis can be used to show how different decisions and measures effect nature conservation and environmental goals, and can be used to make recommendations on how to prioritize measures in a spatial perspective. Within IMAGINE, we applied scenario-based analysis in three case studies focusing on shore exploitation, trawl fishing and climate change. As an example of potential effects of exploitation, we evaluated the effect on eelgrass habitat of different alternatives for regulating jetty development in the Koster Sea over the next 30 years. We calculated the total area and the proportion of shallow areas with expected disturbance based on different development rates for jetty construction, as well as changed placement of newly added jetties to minimize the impact on eelgrass. The impact of trawling on sea pen habitats was investigated by comparing current conditions with occurrence of sea pens modelled based on data from a less affected reference area, thus demonstrating the possible long-term effect of reduced trawling. The effects of climate change on the marine environment were investigated by applying climate development scenarios from SMHI. The expected temperature increase will most likely lead to lower salinity in the Baltic Sea. As salinity limits the distribution of marine organisms in the Baltic Sea, the occurences of important habitat-forming species such as the blue mussel and bladder-wrack are likely to change as well. Based on our scenarios, we evaluated the potential and limitations of various legal planning and nature conservation instruments to achieve the goal of preserving and developing a marine green infrastructure. We further suggest how these instruments can be developed and adapted to ensure that knowledge and understanding of marine green infrastructure can be integrated into national, regional, and local decision-making. The results of our case studies show that to assess and integrate cumulative effects of different pressures, geographically defined information on both activities and nature values is needed, as well as legal measures that ensure a landscape perspective in planning, decision-making and management.
Technical Report
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SUMMARY: Sweden has a long and beautiful coastline with extensive archipelagos that offer exceptional conditions for recreational boating. There are more than 700 000 recreational boats in Sweden, which is one of the highest numbers in the world in relation to the population size. Small tidal differences and many sheltered bays also provide good conditions for storing boats at docks and piers and jetties. As a result, large areas of the Swedish coast are today covered with docks and marinas for recreational boats. The large number of boats and docks could have substantial negative effects on the environment. However, the understanding of the cumulative impact of recreational boating on Swedish coastal ecosystem has so far been incomplete. The goal with this report from the Swedish Institute for the Marine Environment has been to compile and summarize the present state of knowledge regarding how recreational boating affect shallow coastal ecosystems in Sweden, to determine the extent of the impact and if the development is sustainable. The aim has been to present scientific knowledge on these topics in an accessible way in order to facilitate the development of a more sustainable management of recreational boating in Sweden. The scientific literature strongly support that recreational boating generates many negative effects on the marine environment. Recreational boating requires a number of physical structures and generate a number activities that each results in several different pressures on the environment. An increased number of marinas, docks and dredged canals results in losses of important habitats, as well as long-term deterioration of the environmental conditions locally. Dredging and dumping of dredge material results in increased turbidity and dispersal of sediment, nutrients and pollutants over large areas with negative effects on many aquatic organisms, e.g. vegetation, fishes and mussels. Traffic from recreational boats and anchoring result in increased turbidity and sediment erosion as well as damage to habitats. Motor boats also create underwater noise that can disturb e.g. fishes, seals and porpoises. In addition, recreational boating result in substantial emissions of toxic substances and pollution from e.g. antifouling paint and combustion engines. More than 60% of all docks and marinas are found in wave sheltered, shallow (<3 m) areas with soft bottoms, despite that this environment only constitute 25% of shallow coastal areas in Sweden. These sheltered areas are well suited for storing boats, but also constitute one of the most productive and valuable environments along the coast. They are important environments for vegetation such as seagrass, pondweed and stoneworts, which in turn constitute important spawning and nursery areas for a large number of fish and invertebrates. The report shows that these shallow soft bottom environments are very sensitive to a majority of the stressors that recreational boating generate. Boating therefore create a disproportionally large impact on environments with high values. Although the impact from a single recreational boat or dock is limited, the cumulative effect is substantial because of the sheer number. According to recent inventories, there are today almost 110 000 docks along the Swedish coast covering almost 2 000 km of bottom. In comparison with the 1960s, the amount of docks has increased with almost 160%, which today constitutes an increase of 1 700 new docks per year. Recent studies show that vegetation is degraded as the number of docks and boats increase within shallow, wave sheltered areas. It is estimated that almost 20% of this important environment is negatively affected by recreational boating today; in the County of Stockholm and Västra Götaland around 30% of shallow, wave sheltered areas are estimated to be impacted. Despite several management measures in the last decades to decrease coastal exploitation, there are no signs that the rate of exploitation is decreasing. The large number of recreational boats with combustion engines, the trend of increasing engine size, and the fact that engines lack all forms of emission control result in substantial emissions of pollutants and greenhouse gases. Recent estimates suggest that the emissions from recreational boats are very high and comparable with other types of transport in Sweden. Emission of toxic copper from antifouling paint on recreational boats is also substantial and contributes to the high levels of copper in coastal waters, which is above the limit for good ecological status in 85% of the assessed coastal water bodies. Although most boat owners likely spend time at sea because they enjoy and care about the environment, the results presented in this report show that recreational boating have a substantial negative impact on the coastal environment, particularly in shallow, wave protected areas. In these areas, today’s use and development of recreational boating cannot be considered sustainable. However, the report also shows that there are ways to decrease the environmental impact from recreational boating. By changing the way we use and store recreational boats, and by improving management we can still allow coming generations to enjoy unexploited coastal environments with clear water and a rich plant and animal life. The report ends by discussing new, possible measures and solutions for a more sustainable use of recreational boats in Sweden, which could be a starting point for continuing such work. These include e.g. to identify vulnerable coastal environments in order to steer away exploitation and recreational boat traffic from these areas. By storing boats on land, the need for docks, dredging and toxic antifouling paint could decrease. Reduced speed limits and access limitations for recreational motorboats in certain areas could decrease negative impact on the most vulnerable habitats. Finally, new, environmentally friendly technology, and new financial instruments could be used to decrease negative impacts and create a more sustainable development of recreational boating. (In Swedish with English Summary)
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Seagrass meadows have extremely high primary and secondary productivity and support a great abundance and diversity of fish and invertebrates. A number of commercially and recreationally important species (including both fish and invertebrates) have been linked to seagrass at some stage of their life cycle, although few such species use seagrass throughout their life. Non-commercial species within seagrass may be an important food source for commercial species (forming trophic linkages). In addition, some species that do not inhabit seagrass may derive benefit from seagrass by way of exported seagrass detritus or resident/transient species that move out of seagrass (some of these topics are dealt with elsewhere in this volume: e.g. Heck and Orth, Chapter 22, Kenworthy et al., Chapter 25 and Bell et al., Chapter 26).
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Fishes are constantly exposed to various sources of noise in their underwater acoustic environment. Many of these sounds are from anthropogenic sources, especially engines of boats. Noise generated from a small boat with a 55 horsepower outboard motor was played back to fathead minnows, Pimephales promelas, for 2 h at 142 dB (re: 1 Pa), and auditory thresholds were measured using the auditory brainstem response (ABR) technique. The results demonstrate that boat engine noise significantly elevate a fish's auditory threshold at 1 kHz (7.8 dB), 1.5 kHz (13.5 dB), and 2.0 kHz (10.5 dB), the most sensitive hearing range of this species. Such a short duration of noise exposure leads to significant changes in hearing capability, and implies that man-made noise generated from boat engines can have far reaching environmental impacts on fishes.
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In 2012, all populations of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus were listed as either threatened or endangered under the U.S. Endangered Species Act. During 2007–2010, researchers documented 31 carcasses of adult Atlantic sturgeon in the tidal freshwater portion of the James River, Virginia. Twenty‐six of the carcasses had gashes from vessel propellers, and the remaining five carcasses were too decomposed to allow determination of the cause of death. The types of vessels responsible for these mortalities were not explicitly demonstrated. Most (84%) of the carcasses were found in a relatively narrow reach that was modified to increase shipping efficiency. To explore the number of Atlantic sturgeon being hit and their horizontal and depth distributions in relation to vessel draft, we conducted telemetry experiments on three living fish (all males) and six dead specimens. While staging (holding in an area from hours to days, with minimal upstream or downstream movements), the adult male Atlantic sturgeon spent most (62%) of the time within 1 m of the river bottom. Assuming that behavior is not modified by vessel noise, adult male Atlantic sturgeon in the James River would rarely encounter small recreational boats or tugboats with shallow drafts; instead, mortalities are likely caused by deep‐draft ocean cargo ships, which have drafts that coincide with the distribution of the tracked adult males. Dead specimens ( n = 6) drifted with the current for several hours to almost 4 d before beaching at distances ranging from 0.5 to over 50 river kilometers from the point of release. We estimated that current monitoring in the James River documents less than one‐third of vessel strike mortalities. A better understanding of Atlantic sturgeon behavior in the presence of vessels will aid in restoring this federally endangered species. Received February 20, 2012; accepted July 19, 2012
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As a consequence of the current globalization of commerce, natural environments are subject to an unprecedented dynamic transport of organisms because global conditions favor transport, settlement, and dispersal of invading species. These produce widespread impacts such as decreased agricultural and utility production, increased health risks to humans and wildlife, and a significant decrease in native biodiversity. On the assumption that it is better to prevent bioinvasions than to control them, it is of paramount importance to identify and manage the potential dispersal vectors to implement preventive strategies. In our study, we identified 4 potential vectors in southern Brazil (sand transport, attachment to hulls of sports fishing boats, water in sports fishing boats, and live fish) for 2 freshwater invasive bivalves (Corbicula fluminea and Limnoperna fortunei). For each of these potential vectors, we assess the potential for dispersal by estimating the probability of finding larvae or adults, setting groundwork for further studies on the risks of invasion to which the region is subject.
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Development of infrastructure around cities is rapidly increasing the amount of artificial substrate (termed artificial reef, 'AR') in coastal marine habitats. However, effects of ARs on marine communities remain unknown, because it is unclear whether ARs can maintain similar communities to natural reefs. We investigated whether well-established (> 30 years old) breakwaters could consistently approximate fish assemblages on interspersed rocky reefs in a temperate estuary over 6 consecutive seasons using regular visual surveys between June 2009 (winter) and November 2010 (spring). We examined whether assemblage differences between reef types were driven by differences in juvenile recruitment, or were related to differences in older life-stages. Assemblages on both reef types were dominated by juveniles (61% of individuals) and sub-adults (34% of individuals). Seasonal fluctuations in assemblage parameters (species richness, diversity, sub-adult abundance) were similar between reef types, and levels of species diversity and assemblage composition were generally comparable. However, abundance and species richness were consistently higher (1.9-7.6 and 1.3-2.6 times, respectively) on breakwaters. These assemblage differences could not be explained by differences in juvenile recruitment, with seasonal patterns of recruitment and juvenile species found to be similar between reef types. In contrast, abundances of sub-adults were consistently higher (1.1-12 times) at breakwaters, and assemblage differences appeared to be driven by this life-stage. Our results indicate that breakwaters in temperate estuaries are capable of supporting abundant and diverse fish assemblages with similar recruitment process to natural reefs. However, breakwaters may not approximate all aspects of natural assemblage structure, with differences maintained by a single-life stage in some cases.
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Coral reef fish larvae use sound to find suitable habitat during their vital settlement stage. Yet boat noise, which can cause stress and avoidance behaviour, and may cause masking via reduction of perceptual space, is common around coral islands and continental shelf habitats due to boat activity associated with fishing, tourism and transport of passengers and cargo. In a choice chamber experiment with settlement-stage coral reef fish larvae of the species Apogon doryssa, the directional responses of larvae were tested to 5 different noise types: Reef, Reef+Boat, Ocean, Ocean+Boat and White noise. The results showed that 69% of fish swam towards Reef playback compared with only 56% during Reef+Boat playback, while 44% of fish larvae moved away from Reef+Boat playback compared to only 8% during Reef playback. Significant directional responses were not observed during White noise, Ocean noise or Ocean+Boat noise playback. Overall, this study suggests that anthropogenic noise could have a disruptive effect on the response of fish larvae to natural reef sound, with implications for settlement and population dynamics in coral reef habitats disturbed by boat traffic.
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The objective of this paper was to review the status of the Malaysian aquatic environment with respect to heavy metals. Much of the work on metals focused on measurements in biota and sediments, but very little research has been done on dissolved and particulate metals in water, metal speciation in sediments or on the bioavailability of metals. Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) received much attention but due to technical difficulties, Arsenic, (As), Mercury (Hg), Tin (Sn) and other hydride elements have not been well studied. The sources of metal pollution come from manufacturing, agriculture, sewage and motor vehicle emissions. The few reliable studies on metals in water indicate that some rivers were contaminated with Pb, Cu and Zn. Measurements in fish, bivalves and shrimp indicate no contamination of these resources by metals. However contamination by Cd and Pb was noted in some littoral shore molluscs such as Thais sp. as well as rock oysters (Saccostrea sp.) which may be due to non-anthropogenic sources. Sediments of the Juru and Langat rivers are contaminated by Pb and Zn, while the Langat River was heavily contaminated by Cd. The concentrations of Zn and Pb in coastal sediments off Juru in Penang, and in the Johor Strait were two and three times higher than global shale values. The source of Pb pollution was thought to be derived from the use of leaded petrol. Metal levels in sediments of the Malacca Strait and the South China Sea were generally similar to global shale values.
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The increasing number of artificial structures in shallow marine waters has provoked research on the ecological function of artificial habitats. The aim of the present study was to investigate interactions between fish and sessile biota growing on urban structures in coastal waterways. The biota growing on subtidal hard substrata is thought to have a large effect on the composition and distribution of associated fish. Hence, in Sydney Harbour, Australia, experiments were done to test interactions between fish and epibiota sampled on pilings at 4 marinas. The abundance and diversity of fish were strongly positively correlated with the amount of foliose algae, mussels and solitary ascidians on pilings. This correlative evidence was further investigated by experimental manipulations of the amount of conspicuous epibiota on pilings. Removal of these organisms showed a marked decrease in the numbers of many types of fish. Conversely, the addition of mussels to pilings increased the abundance and diversity of associated fish. The cover of complex epibiota on pilings at marinas may strongly affect the abundance of many species of fish and therefore influence the types of fish that recruit to these artificial habitats. Such knowledge on the ecological processes occurring in marinas is an important step in recognising the value of these artificial structures as habitat for marine organisms.
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The use of telemetry is widespread in fisheries research, and manual tracking of fish is considered acceptable for data collection. However, it has never been shown whether the use of boats with powered engines, which is common in manual tracking, influences the distribution and behavior of fish. We examined whether general boat traffic or focused manual tracking activity altered movement patterns of adult lake trout Salvelinus namaycush in a small boreal lake at the Experimental Lakes Area of northwestern Ontario, Canada. In the summer and fall of 2002, we used automated fish positioning systems to compare the behavior of lake trout during 1-h disturbance periods (boat traffic or manual tracking) with behavior in the preceding 1-h baseline periods (no disturbance). In addition, we compared behavioral differences of lake trout during disturbance and baseline periods (experimental trials) with a similar period of time when no boats were on the lake (control trials). This comparison allowed us to determine whether the observed changes in behavior during normal boat traffic or manual tracking were within the natural range of variation. Overall, we observed no effect of boat traffic or manual tracking on the depth, speed, and path predictability of lake trout. Similarly, the changes in lake trout behavior between the disturbance and baseline periods of the experimental trials were all within the natural range determined by control trials. The response of lake trout to manual tracking was not related to their proximity to the motorboat, both when lake trout were in deep water (6 m; summer) and when they were in shallow water (2 m; fall spawning season). The lack of significance of the relationship between patterns of fish behavior and manual tracking activity provides support for the continued use of this method in fisheries research.
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Recent improvements in mapping of global population distribution makes it possible to estimate the number and distribution of people near coasts with greater accuracy than previously possible, and hence consider the potential exposure of these populations to coastal hazards. In this paper, we combine the updated Gridded Population of the World (GPW2) population distribution estimate for 1990 and lighted settlement imagery with a global digital elevation model (DEM) and a high resolution vector coastline. This produces bivariate distributions of population, lighted settlements and land area as functions of elevation and coastal proximity. The near-coastal population within 100 km of a shoreline and 100 m of sea level was estimated as 1.2 × 109 people with average densities nearly 3 times higher than the global average density. Within the near coastal-zone, the average population density diminishes more rapidly with elevation than with distance, while the opposite is true of lighted settlements. Lighted settlements are concentrated within 5 km of coastlines worldwide, whereas average population densities are higher at elevations below 20 m throughout the 100 km width of the near-coastal zone. Presently most of the near-coastal population live in relatively densely-populated rural areas and small to medium cities, rather than in large cities. A range of improvements are required to define a better baseline and scenarios for policy analysis. Improving the resolution of the underlying population data is a priority.
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Anthropogenic (man-made) noise is a global problem and present in virtually all terrestrial and aquatic environments. To date, most studies investigating the potential impact of this pollutant have focused on individual behavioural responses and simply considered whether noise has an effect. However, most animals engage in social interactions, which may be vulnerable to the adverse effects of noise, and work in other fields suggests that individuals might react differentially to comparable noise stimuli depending on their own characteristics and the current situation. We used controlled experiments and standardized tests to investigate the impacts of playback of the noise of a passing boat, a dominant acoustic stressor in the aquatic environment, on nest-digging behaviour, antipredator defence and social interactions in small groups of Neolamprologus pulcher, a territorial and cooperatively breeding cichlid fish. Our results show that, in comparison to ambient noise, playback of boat noise: (1) reduced digging behaviour, which is vital to maintain hiding and breeding shelters; (2) decreased defence against predators of eggs and fry, with direct consequences for fitness; and (3) increased the amount of aggression received and submission shown by subordinates. Moreover, the context (presence or absence of eggs) affected individual and social behaviours in response to the same noise source. Our results demonstrate the need to consider whole behavioural repertoires for a full understanding of the impact of anthropogenic noise, and indicate that the effects of this global pollutant are likely to be context dependent.
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Personal watercraft (water scooters, jet skis) were recorded under water in Bramble Bay, Queensland, Australia. Underwater noise emissions consisted of broadband energy between 100 Hz and 10 kHz due to the vibrating bubble cloud generated by the jet stream, overlain with frequency-modulated tonals corresponding to impeller blade rates and harmonics. Broadband monopole source levels were 149, 137, and 122 dB re 1 μPa @ 1 m (5th, 50th, and 95th percentiles). Even though these are lower than those of small propeller-driven boats, it is not necessarily the broadband source level that correlates with the bioacoustic impact on marine fauna.
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1. A study was set up in the Port-Cros National Park in order to determine the effects of boat anchoring on Posidonia oceanica seagrass beds.2. Experiments on the effects of anchors on the seagrass meadows revealed that, on average, 34 shoots were destroyed during an anchoring cycle (lock-in and retrieval), especially when the seagrass mat compactness is weak and the extent of rhizome baring is high.3. Five parameters of the Posidonia oceanica beds (meadow cover, shoot density, extent of rhizome baring, proportion of plagiotropic rhizomes, degree of meadow fragmentation) were considered and it was shown that the extent of rhizome baring was not correlated with anchoring pressure. Meadow cover and mean shoot density were positively correlated with high anchoring pressure.4. The proportion of plagiotropic (i.e. horizontally growing) rhizomes and the degree of meadow fragmentation were positively correlated with moderate anchoring pressure. Copyright © 1999 John Wiley & Sons, Ltd.
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Over the last 30 years, the use of motorised recreational craft on inland waters has increased significantly, and it is likely that this trend will continue. The growing use of rivers, lakes and water storage reservoirs for recreational purposes has led to concerns about increasing anthropological pressures on freshwater environments. As a result, numerous studies focusing on the possible impact of power boats on inland waterbodies have been undertaken since the early 1970s, when attention started to be drawn to environmental impacts associated with this type of recreation. This paper presents an overview of identified and documented physical, chemical and biological impacts as a result of motorised recreational activities on lakes and reservoirs. Relevant literature, including research papers, government reports and bibliographies, was consulted in the preparation of this review. It has become obvious that in the past, biological impacts have been underestimated. Thus, there is a need for further, more focused, research into the impacts on not only freshwater ecosystems but on terrestrial biota surrounding recreational waters.
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Each book has two main goals 1. Determine baseline concentrations of metals and metalloids in tissues of representative field populations of estuarine coastal, and open ocean organisms (Book 1:algae and macrophytes, protists, sponges, coelenterates, molluscs, crustaceans, insects, chaetognaths, annelids, echinoderms, and tunicates) (Book 2: elasmobranchs, fishes, reptiles, birds, mammals) and their significance to organism health and to the health of their consumers. 2. Synthesize existing information on biological, chemical, and physical factors known to modify uptake, retention, and translocation of each element under field and laboratory conditions. Recognition of the importance of these modifiers and their accompanying interactions is essential to the understanding of metals kinetics in marine systems and to the interpretation of baseline residue data. Synthesizes existing information on biological, chemical, and physical factors known to modify uptake, retention, and translocation of each element Aids understanding of metals kinetics in marine systems Allows the interpretation of baseline residue data.
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Although behavioral deterrent systems, directed at exploiting fish sensory systems, are the common place in fisheries management, little is understood about the link between imposed sensory signals (e.g., sound intensity) and the resulting fish movements. Here, an advection–diffusion equation, incorporating a stimuli specific repulsive flux, is coupled with calculation of the generated stimulus field in order to model fish movement near a behavioral deterrent system. A stability analysis of this model is then used to determine the effectiveness of a deterrent stimulus to disrupt the natural movement of fish. Results of laboratory experiments of a bubble curtain to inhibit common carp, Cyprinus carpio, movement are used to develop the model and verify stability analysis predictions. This experimental data demonstrate that the acoustic stimulus (sound pressure levels) produced by bubble curtain systems can be sufficient to disrupt the natural movement of carp, i.e. inhibit fish passage. In addition, a sensitivity analysis is used to investigate how model stability is impacted by changes in movement behaviors (i.e. diffusion and advection rates). This coupling of a movement model and stability analysis could find general application in the assessment of behavioral deterrent systems, in particular at field sites where long term physical testing may be impractical.
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The concentrations of lead, cadmium, copper, zinc, iron, and mercury in the water, sediment and biota of the Singapore River were determined. The concentration of the various metals in water showed significant variation at different sampling times and there was enrichment of lead content. The spatial patterns of metal distribution in the sediment could be due to the different pollution sources such as exhaust emission from boats and other environmental variables such as clay content of sediment or tide level. In the biota, higher amounts of metals were found in species inhabiting the river bed while organisms of higher trophic level such as free-swimming fishes and crabs accumulated lower amounts. In general, the flesh of fishes and crabs had the least content of metals compared to other tissues. The Concentration of various metals in bivalve, Mytilopsis sallei, which were found extensively in the river did not reflect the pollution distribution.
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An underwater camera system was designed to record the behavior of male nest-guarding longear sunfish (Lepomis megalotus) during periods of boating activity. Boats traveling at slow speeds near nests usually drove males from their nests, increasing the likelihood of egg predation. Boats moving at higher speeds or further from nests caused little or no displacement of males, but increased turbidity and possible success of predators. Location of a nest near cover increased the male's ability to protect his nest during repeated surface disturbances.