Article

Abiotic and biological differences in ballast water uptake and discharge samples

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Abstract

During the type approval process of ballast water management systems (BWMS) performance tests need to be conducted according to the BWMS Code (previously Guidelines G8) of the International Maritime Organization (IMO). The shipboard tests previously included a control experiment with untreated ballast water to evaluate the BWMS performance by comparing test results of treated and untreated water. Biological results and abiotic parameters of 97 control water tests conducted during the last >10 years during ballast water uptakes and corresponding discharges were summarized. In general, a strong decline of organisms in ballast tanks was observed, especially during the first few days of the holding time. The IMO validity criteria for uptake water phytoplankton in shipboard control tests were met in 82.5% of all tests. Phytoplankton numbers below the validity criteria occurred predominantly in winter and/or when the water was taken up offshore. For zooplankton the validity criteria were always met. The TSS and POC content in our ballast water uptake samples was frequently much higher than required during IMO BWMS type approval tests so that the current testing requirements do not represent a challenge to BWMS. With this a risk is taken that type approved BWMS fail in water conditions which occur frequently in the real world.

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... Most ship operators will aim to comply with the D-2 standard through onboard installation of a ballast water management system (BWMS) that typically apply a combination of physical, chemical or biological methods to reduce organism viability in ballast waters (Gollasch and David, 2021). Each BWMS technology is certified through a set of standardized land-based and ship-board tests to demonstrate ability to meet the D-2 standard requirements under a specified range of abiotic water conditions with no harm to the ship, its' crew, the environment, and public health (IMO, 2008;IMO, 2018b). ...
... Several alternatives have been discussed to manage challenging water quality, including bypassing the BWMS while water quality is poor and requiring ships to conduct ballast water exchange and treatment on high seas prior to the next port of call (IMO, 2021;IMO, 2022bIMO, , 2022c. While this option may keep BWMS units operational, bypassing the BWMS on multiple occasions may result in uptake of high volumes of sediment containing benthic organisms (Gollasch and David, 2021). While data were not available to include bypass as a factor in this study, it will be important to determine the effect of bypass on subsequent ballast discharges through compliance testing, following proposed guidelines to enhance recording and reporting of bypass activities (IMO, 2023a). ...
... The monitoring units of these systems may indicate no sign of failure, and there can be several reasons why the ship is not able to comply with the D-2 standard in operational service. In addition, previous research has indicated that testing requirements of the type approval guidance of the IMO (BWMS Code) do not necessarily represent water qualities that these systems encounter in all natural aquatic environments (Gollasch and David, 2021). Conversely, the implementation of BWMS Code is relatively recent (IMO, 2018b), and ships' crews may be battling a steep learning curve such that compliance rates may yet improve with additional years of experience. ...
Article
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Ships’ ballast water and sediments are vectors that contribute to the unintentional spread of aquatic non-native species globally. Ballast water management, as well as commissioning testing of ballast water management systems and compliance monitoring under the regulations of the International Maritime Organization (IMO) aim at minimizing the unwanted spread of organisms. This study compiles data for treated ballast water samples collected and analyzed from 228 ships during 2017–2023. The samples were collected from the ballast discharge line or directly from the ballast tank for enumeration of living organism concentrations in the categories of ≥50µm and <50 to ≥10µm -sized organisms, as well as indicator microbes in comparison to the ballast water performance standard of the IMO (Regulation D-2). In addition, several ship-specific factors were examined to infer potential factors affecting compliance rates. Nearly all ships were compliant with the ballast water performance standard for indicator microbes and <50 to ≥10µm -sized organisms, whereas almost half of all samples exceeded the limit of ten viable organisms m⁻³ for the ≥50µm -sized organisms. Compliance testing results did not differ significantly between sampling years, indicating that compliance rate did not change through time. The rate of compliance was higher for commissioning testing than compliance testing. Clear ship- or system-specific factors that lead to compliance or non-compliance were not detected, even though type of ballast water management system, filter mesh size associated with the system and source of ballast water affected compliance significantly either for the samples taken from the discharge line, or ballast tank. As compliance did not improve significantly over time, compliance testing of ships’ ballast water should be undertaken to ensure that the systems remain operational after commissioning and ships meet requirements of the D-2 standard. Furthermore, the study outcomes promote further research on the efficiency of filter mesh sizes and different filtration units associated with ballast water management systems, to improve mechanical removal of larger organisms. Finally, as several ships exceeded the compliance limit by hundreds or thousands of living organisms, technological advancements and operational measures may be needed to improve the overall reliability of ballast water management.
... The transfer and discharge of ballast water from ships is currently the main pathway leading to the invasion of alien organisms through offshore waters (about 29% of total biological invasions) [3], and it is estimated that approximately 3000 species are transferred through ship ballast water every day [4]. A large number of potentially pathogenic microorganisms have been detected in river estuaries, ports, and bays, posing potential harm to aquatic organisms and human health [5]. Therefore, ballast water is a mobile carrier for the global transfer of bacteria and genes, which has been attracting much attention in recent years [6]. ...
... When antibiotic-resistant bacteria in ballast water are gradually enriched, the transfer of antibiotic-resistant genes between microbial communities occurs [28]. It has been proven that there are more ARGs in ship ballast water than in samples taken from the nearby ocean [5,35,36]. In addition, ARGs were found in many samples of ballast water from different sea areas, which shows that ballast water can spread antibiotic resistance [21]. ...
... In recent years, the proliferation of ARGs has gradually evolved into a serious global problem [5], and ARGs have been detected in sewage, rivers, inshore fishing grounds, marine sediments, and inshore seawater [56,[60][61][62][63][64]90]. Seawater containing ARGs and human bacterial pathogens (HBPs) will be pumped into the ballast tank of the ship and then discharged to the port sea area of the destination [91]. ...
Article
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The misuse of antibiotics causes antibiotic resistance genes (ARGs) in bacteria to be gradually enriched by environmental selection, resulting in increased tolerance and resistance in bacteria to antibiotics. Ballast water is a mobile carrier for the global transfer of bacteria and genes, thus posing a certain risk of ARGs spreading into the global ocean. Therefore, it is important to investigate the current status of ARGs in ballast water, as well as control the abundance of ARGs. Herein, we attempt to comprehensively summarize the distribution and abundance of ARGs in ballast water from different sea areas and analyze the influencing factors (such as physical factors, chemical factors, temperature, pH, etc.) on the distribution of ARGs. Furthermore, we seek to review the changes in ARGs after differential disinfection technology treatment in ballast water (including chlorination, ultraviolet, ozone, and free radical technology), especially the enhancing effect of subinhibitory concentrations of disinfectants on ARGs transfer. Overall, we believe this review can serve as a guide for future researchers to establish a more reasonable standard of ballast water discharge that considers the pollution of ARGs and provide new insight into the risk of vertical and horizontal ARG transfer in ballast water after disinfection.
... The establishment of non-native species could be determined by the recurrence of an inflow of a species to a location outside its native range, and the biotic and abiotic conditions [17]. The wide variation in abiotic factors inside ballast tanks has also been reported [18] and although generally the viable number of phytoplankton and zooplankton drops within the holding time, it is not enough to meet the discharge standards. ...
... Consequently, this fact should, perhaps, be taken into account in the discharge standards [9]. Additionally, it has also been demonstrated that the abiotic factors in ballast waters and receiving environments can vary widely and organisms in ballast waters are not fully decay by these abiotic factors [18]. In order to overcome these challenging conditions properly, the assessment and validation of ballast water treatment systems that can efficiently overcome these two factors (biotic and abiotic) is encouraged. ...
... In order to overcome these challenging conditions properly, the assessment and validation of ballast water treatment systems that can efficiently overcome these two factors (biotic and abiotic) is encouraged. Thus, it should involve a "worst case scenario" that could occur in real water conditions [18,73]. Additionally, the development of efficient ballast water management systems in these scenarios would also benefit some related industries, such as aquaculture, which is also, potentially, affected by possible spread of organisms resulting from an inadequate ballast water management [61,70]. ...
Article
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New observations of non-indigenous species (NIS) in coastal waters, such as the Gulf of Cadiz (Spain) have increased since 1980 and more or less exponentially in the last five years. Ballast water has become the most significant pathway for unintentional introductions of NIS into marine ecosystems. For example, the marine larvae of crustacean decapods that inhabit the water column could be transported in ballast water. Although elevated concentrations of metals are toxic to many marine organisms, some of them have evolved effective detoxification, or avoidance mechanisms making it possible to consider they have a superior ability to withstand exposures to these toxicants. In this text, we try to reinforce the hypothesis that anthropogenic modifications (such as chemical alterations and modified environments) benefit NIS with broad environmental tolerances. Taking these risks into account, a reinforcement of efficient Ballast Water Management Systems to respond to today’s challenging environmental conditions is discussed.
... In reality, uptake concentrations could differ from arrival concentrations due to reproduction, death or BWE. Increasing salinity and tank temperature generally cause zooplankton and phytoplankton concentrations to decline with holding time (Gollasch & David, 2021). However, some species can reproduce in tanks (e.g. ...
... However, some species can reproduce in tanks (e.g. Bailey et al., 2005;Carney et al., 2017;Gollasch et al., 2000), and egg-carrying copepods (Gollasch & David, 2021) and juvenile zooplankton (Cabrini et al., 2019) have been observed in ballast samples. Thus, it is likely that population growth and decline both occur during the voyage, with the outcome being voyage-specific (Chan, Bradie, et al., 2015;Gray et al., 2007;Simard et al., 2011). ...
Article
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Ballast water is recognized as a leading pathway for the introduction of aquatic non‐indigenous species which have caused substantial ecological damage globally. Following international regulations, most international ships will install a ballast water management system (BWMS) by 2024 to limit the concentration of aquatic organisms in ballast water discharges; however, these new technologies may not operate as expected at global ports having variable water quality or may periodically malfunction. Using simulations informed by empirical data, we investigated the risk of non‐indigenous species establishment associated with BWMS inoperability and evaluated potential mitigation strategies. Scenarios considered included bypassed or inoperable BWMS achieving no reduction in organisms, and partially functioning BWMS with discharged organism concentrations exceeding permissible limits. These scenarios were contrasted to outcomes with fully functioning BWMS and to voyages where ballast water exchange (BWE) was used to mitigate risk. Partially functioning BWMSs were nonetheless beneficial, reducing organism concentrations in ballast and thus establishment risk. When a BWMS is bypassed or partially functioning, BWE is a useful emergency mitigation measure, reducing establishment risks more than partial BMWS. However, the greatest risk reduction was achieved when partial BWMS and BWE were combined. Voyage‐specific characteristics such as concentration of organisms at uptake and destination port salinity can affect the optimal management strategy for voyages when the BWMS does not achieve compliant discharges. Synthesis and applications. The risk of aquatic invasions and their associated ecological damages can be substantially reduced by using a ballast water management system (BWMS) and/or ballast water exchange (BWE). When a BWMS is inoperable, appropriate mitigation measures should be decided on a trip‐by‐trip basis considering voyage route and reason for BWMS inoperability (when known). BWE is a useful strategy for reducing invasion risk, except when uptake concentrations are very low. Combining BWE and partial BWMS always reduced risk compared with BWE alone, but did not greatly reduce risk when uptake concentrations were high.
... To date, more than 80 BWMSs have been recognized and approved for use by the IMO, and more than 10,000 BWMSs have been installed and put into service on board ships [50]. However, while the BWMS was able to bring BW into compliance with the D-2 standard in the type approval test, numerous studies have shown that noncompliance still exists in the discharged water of the ships that have installed and are using the BWMS [51][52][53]. Some external factors may affect the treatment effectiveness of BWMSs, such as season and water quality [50]. ...
Article
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Ballast water (BW) poses the risk of introducing species. Therefore, ships install the ballast water management system (BWMS) to reduce the risks caused by BW. To gain a deeper understanding of the treatment effectiveness of the BWMS, in this study we compared the effectiveness of four different treatment processes of BWMSs on seawater phytoplankton, which were electrochlorination treatment, hydroxyl radical oxidation treatment, membrane separation and deoxygenation treatments, and UV irradiation treatment. The results showed that all four BWMSs had a reduction in phytoplankton density of over 99%. In terms of phytoplankton taxa, the effectiveness of the four BWMSs was different. The taxa removal rates of the four BWMSs were 81.25%, 39.58%, 59.31%, and 74.49%, respectively. Electrochlorination treatment and UV irradiation treatment were significantly more effective than hydroxyl radical oxidation treatment and membrane separation and deoxygenation treatments. The residual phytoplankton taxa were mainly dinoflagellate and diatoms, such as Cucumeridinium, Prorocentrum, Navicula, and Skeletonema. Taxa that can tolerate treatment may be more likely to survive and reproduce. There is still a need to continue to strengthen the development and research on the BWMS in the future to promote the development of BW management.
... Available literature indicates that organism concentrations can change following uptake owing to species performance differences while resident in a ballast tank (David et al. 2007;McCollin et al. 2008). Both zooplankton and phytoplankton concentrations tend to decline with holding time in ballast tanks (Gollasch and David 2021), lack of light and/or food , and unfavourable conditions . However, some species have been reported to reproduce and increase in population size while in ballast tanks Ardura et al. 2021). ...
Article
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Approximately 65% of established non-indigenous species (NIS) identified in the Great Lakes–Saint Lawrence River basin (GLSLR) since 1959 were introduced by ballast water discharges from transoceanic vessels. While the rate of new detections has sharply declined, NIS already present may spread within the system—including upstream—through secondary invasions by domestic ballast water transferred mainly by ‘laker’ vessels. Canada has mandated that all vessels loading or unloading in waters under Canadian jurisdiction in the GLSLR will need to use ballast water management systems (BWMS) by 2030. Here we used simulations informed by empirical data to investigate the expected efficacy of BWMS in reducing zooplankton and phytoplankton introductions on a per-trip basis, and the corresponding probabilities of survival and establishment related to ballast water discharges within the GLSLR. We investigated three ballast water scenarios: no treatment, full treatment, and treatment by a partially-functioning BWMS (owing to malfunctions or challenging water quality). Fully-functioning BWMS reduced community pressure by > 99% and corresponding establishment risk of NIS by 38% and 66% relative to untreated ballast discharges for zooplankton and phytoplankton, respectively. Partial treatment (modelled as a 95% reduction in organism concentrations) resulted in 10–20% reduction in per-trip probability of NIS establishment; results indicate that trips with BWMS inoperability caused by highly turbid uptake conditions may be less risky than trips with BWMS inoperability due to plankton blooms. The implementation of BWMS is expected to reduce risk of secondary spread within the GLSLR system by ballast water, even if the BWMS are subject to periodic malfunction.
... (3) survive, reproduce, and establish a community in the new environment of destination port; and (4) further spread and impact to the new environment via coastal currents or domestic shipping (Hallegraeff 1998). However, most reports have focused on step 2 as the biological performance of ballast water during ballasting, storage, and discharge operation on the ship (DiBacco et al. 2012;Dong et al. 2021;Gollasch et al. 2019;Gollasch and David 2021;Kang et al. 2010;Lin et al. 2021;Lv et al. 2018;Wang et al. 2020Wang et al. , 2022. Unfortunately, a limited number of studies carried out germination experiments to determine the cyst viability in BWTS (Hallegraeff 1998;Hallegraeff and Bolch 1992). ...
Article
Full-text available
The foreign dinoflagellate cysts in ships’ ballast water tank sediments (BWTS) can be viable for a long time under hostile storage conditions. It is crucial to understand the detailed mechanisms of harmful biological invasions in estuary ecosystems. To study the relationship between the abundance of dinoflagellate cysts and environmental factors, cyst assemblages were analyzed in 7 sediment samples, collected from one international commercial ship that arrived in Shanghai in August 2020. Twenty-three dinoflagellate cyst taxa were identified in 5 groups, including autotrophic (9) and heterotrophic (14) species. Distribution of dinoflagellate cysts in the different ballast water tanks is heterogeneous. Dinoflagellate cysts in BWTS of the repaired ship were dominated by Scrippsiella acuminata, Protoperidinium leonis, Protoperidinium oblongum, Lingulodinium polyedra, Alexandrium tamarense/A. catenella, Protoperidinium pentagonum, and Protoperidinium subinerme. The abundance of the dinoflagellate cysts in each tank ranged from 80.69 to 330.85 cysts g⁻¹ DS (dry sediment). Multivariate statistical analyses revealed that the variation in cysts from different tanks had positive correlations with total nitrogen (TN), total phosphorus (TP), and pH and negative correlations with total organic carbon (TOC) except for sample TK5. For germination of dinoflagellate cysts in BWTS, 12 species were germinated in 40 days and cysts of potentially toxic dinoflagellate species were more abundant than those of non-toxic species. Results show that potentially viable and harmful/toxic dinoflagellate cysts are present in BWTS of ships arriving in Shanghai, China. Consequently, knowledge obtained in this study can be valuable for further managing of potential biological invasion of the Yangtze River Estuary.
... The transportation of invading species to new habitats with ship's ballast water, one of the crucial threats to marine life, is the issue that has been emphasized due to the dramatic increase observed in recent years (Canning-Clode and Carlton, 2017;GESAMP, 2019). Ballast water management (David and Gollasch, 2018;Liu et al., 2019;Scriven et al., 2015), the ballast water sampling process (Gollasch and David, 2017), the differences in the content of ballast water between the intake and discharge (Gollasch and David, 2021;Tolian et al., 2020), risk assessment of ships caused by ballast water Cheng et al., 2019) are the subjects studied in recent years. To prevent risks caused by ballast water, nowadays, physical-mechanical techniques (filtration, hydrodynamic cavitation, cyclonic separation, ultrasonication, heat treatment, UV treatment, electro-ionization, magnetic separation) and chemical techniques (oxidizing biocide producing, chlorine biocide, ozone, hydrogen peroxide, strong ionization discharge, deoxygenation, paraclete biocide, electro chlorination, and electrochemical treatment) are applied on board (Lakshmi et al., 2021;Sayinli et al., 2022). ...
Article
Ocean and marine environments face the adverse effects of climate change and environmental pollution. Maritime transportation, one of the most severe marine pollution sources because of ship-sourced operations, poses risks to the marine environment in many types and ways. A robust risk assessment should be organised to identify causal mechanisms and the resources of the pollution. In this study, the steps of ship operations that may cause marine pollution and the structure of the relations between them were established based on their expert opinions and the information contained in the literature. On this basis, the probabilities of each ship's operations that cause marine pollution are computed by the Fuzzy Bayesian Network approach. The extent of the response operation according to the level of marine pollution is determined by the Bow-tie approach. As a result, the procedures that cause funnel gas emissions are the riskiest. The study will be beneficial for the practitioners of safety and environmental management in maritime transportation to make decisions practically and strategically.
... Taking shippingmediated range expansions as an example, marine invaders adhered to the hull of shipping vessels or sucked into ballast tanks must endure severe environmental challenges during subsequent shipping voyages such as salinity and temperature fluctuations ∼15% and ∼20 • C, respectively (Briski et al., 2013). Such dramatic environmental fluctuations can be recurring during the whole shipping voyage such as during ballast water exchanges and environmental changes in trans-oceans (Ibrahim and El-Naggar, 2012;Gollasch and David, 2021). However, the underlying mechanisms of rapid environmental adaptation and assimilation still remain elusive. ...
Article
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Deoxyribonucleic acid methylation and gene transcription have been proved as two underlying mechanisms involved in rapid plastic response to environmental stresses. However, it remains elusive on how DNA methylation regulates gene transcription under acute and recurring environmental challenges to form the stress memory, further contributing to invasion success during range expansions. Using a model invasive species Ciona robusta, we investigated the regulatory roles of DNA methylation on gene transcription and their contribution to the formation of stress memory at 30 genes under acute and recurring osmotic challenges simulated during the invasion process. We found the bimodal distribution of methylation level for the 68 mCpGs identified across all the genes after challenges, but only five sites were significantly correlated with the expression of their corresponding genes. These genes participated in the biological processes of Ca²⁺ transport and metabolism of lipid and proline. At the DNA methylation level, we found two early-responding and four tardy-responding sites of stress memory and these sites were functionally related to genes involved in the biosynthesis of proline, metabolism of lipid, and transport of taurine and Ca²⁺. At the transcriptional level, three tardy-responding and five early-responding memory genes were involved in the transport of ions, regulation of water channels, biosynthesis of taurine, and metabolism of lipid. Altogether, the findings here suggest that DNA methylation and gene transcription should work in concert to facilitate the formation of stress memory, thus further improving the performance of invaders under recurring environmental challenges during biological invasions.
... For preserved samples, typically, it has been assumed that organisms with intact cellular content were alive at the time of collection, although Lugol's acid stains and shrinks cells resulting in difficult taxonomic identification. More recently (last 10-15 years), abundance and viability of cells have been assessed using fresh samples (unpreserved) in line with IMO guidelines for sample analysis associated with type approval testing of BWMS [IMO (International Maritime Organization), 2016; see also Veldhuis and Kraay, 2000;NSF International, 2010;Steinberg et al., 2011;Gollasch and David, 2021]; samples should not be concentrated for analysis unless the procedure has been validated to ensure that cells are not damaged by the process, however, validation is less feasible for shipboard ballast water sampling than at land-based type approval facilities. As cell abundances will be lower in unconcentrated samples, a sufficient volume must be analyzed to obtain a reliable estimate of the number of living cells (NSF International, 2010). ...
Article
Full-text available
Global coastal aquatic ecosystems are negatively impacted by the introduction of harmful aquatic species through the discharge of ships’ ballast water. To reduce discharges of harmful aquatic organisms and pathogens, such as toxic phytoplankton species, ships are now transitioning to the use of ballast water management systems (BWMS) instead of ballast water exchange (BWE). This study examines the abundance and diversity of phytoplankton in ballast water managed by BWMS (or a combination of both BWE + BWMS) in comparison to those in ballast water managed by BWE alone (collected from ships arriving to Canada’s Pacific coast in 2017–2018 and 2008, respectively). The abundance and diversity of phytoplankton species were also examined in relation to key variables such as ballast water salinity and ballast water age. Total abundance of phytoplankton was significantly lower in preserved samples managed by either a BWMS or BWE + BWMS compared to BWE alone. Abundances in preserved samples were higher than observed in fresh (unpreserved) samples at the time of collection, with all samples managed by a BWMS meeting international limits for the number of viable organisms ≥10 and <50 μm in minimum dimension (based on six 1-mL live counts). While there was no apparent influence of factors such as treatment type [e.g., ultraviolet (UV) or chlorine], presence of filtration, ballast water salinity, ballast water age, nor location of last ballast water uptake on phytoplankton abundances in preserved samples, power to detect differences may be limited by sample size. Ballast water managed by BWMS also tended to have lower abundances of harmful phytoplankton species, although the difference was not statistically significant – additional research into the community composition of live cells in fresh samples could be valuable to discriminate the risk associated with phytoplankton surviving ballast water treatment.
Chapter
This chapter highlights the challenges involved in the type approval testing of Ballast Water Management Systems (BWMS). IMO required such tests with its Guidelines G8. This guideline was prepared with best efforts during substantial debates, but in practice, some requirements turned out not to be relevant, and other important aspects were found to be missing. It was concluded at IMO that the Guidelines G8 requirements do not represent enough challenging test conditions to represent all waters where ballast water is taken up by vessels. Therefore, BWMS which have received type approval under the previous Guidelines G8 may be found non-compliant if BWMS is operated in more challenging water conditions as the system was exposed to during the tests. MEPC67 (October 2014) agreed that Guidelines G8 should be revised. The revision process ended at MEPC70 in October 2016. In further discussions, BWM Convention Contracting Governments expressed the view that the new Guidelines G8 should not have a voluntary or recommending nature but should become a mandatory instrument. Therefore, the language in this guideline was edited accordingly and it was renamed as a code, i.e., Code for Approval of Ballast Water Management Systems (BWMS Code). This book chapter describes the Guidelines G8/BWMS Code editing suggestions of the authors, which were based on their long-lasting experience in testing BWMS, and it continues to describe the agreed BWMS Code amendments. Independently of IMO work, the United States Coast Guard established their own BWMS test guidelines. The differences of these guidelines compared to the BWMS Code are also discussed, and recommendations are suggested to improve the test regime to make BWMS more fit for purpose.
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We conducted a shipboard ballast water test using seawater of extreme turbidity collected from Shanghai Port (China) (>300 mg total suspended solids (TSS)/L), and normal seawater collected in other ports (<100 mg TSS/L). All three types of International Maritime Organization (IMO)-approved ballast water management system (BWMS) tested failed to properly operate because of filter clogging or insufficient generation of oxidants under near-fresh water conditions with extremely high concentration of suspended solid during ballasting. It was also found that the number of microorganisms increased with longer ballast water retention time, with higher numbers in the treated discharge water. The results suggest that when operating a BWMS involving a filter unit in areas with water having high concentrations of suspended solids, the filter unit should be used during ballast water discharge, rather than during ballasting. This method has the advantage of removing ≥50 µm organisms at discharge that could not be removed by a filter during ballasting. For ballast water retained for long storage times, the results suggest the use of BWMSs involving UV units or electrolysis during deballasting. In addition, BWMSs involving electrolysis units provide the opportunity to maintain residual total residual oxidant (TRO) levels, using a partial ballast tank. Although the BWMSs tested are a small subset of the large number of IMO-approved BWMSs, the results demonstrate that there is a significant gap between the technology currently available and capacity to meet IMO and US Coast Guard standards.
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Invasive species pose a significant threat to a primary objective of marine conservation, protecting native biodiversity. To-date, research quantifying invasion risk to marine protected areas (MPAs) is limited despite potential negative consequences. As a first step towards identifying invasion risk to MPAs via vessel ballast or biofouling, we evaluated vessel traffic patterns by applying graph-theoretic concepts for 1346 vessels that connected invaded areas (‘invasion nodes’) along the Northeast Pacific coast to MPAs within Canadian waters in 2016. We found that 29% of MPAs overlapped with invasion nodes and 70% were connected to invasion nodes via vessel traffic. Recreational vessels were most prevalent within invasion and MPA nodes, made the most connections between invasion nodes and MPAs, and spent the most time within nodes. Vessel connections increased in summer and with spatial extent and dock area at invasion and MPA nodes, as well as for MPAs with minimal regulatory protection. Results from this work highlight risk posed by vessels as a vector for nonindigenous species spread and present an opportunity to develop improved management measures to help protect MPAs. Such an approach can be applied to vector interactions with protected areas across biomes for targeted invasion management.
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Ships' ballast tanks have long been known as vectors for the introduction of organisms. We applied next-generation sequencing to detect dinoflagellates (mainly as cysts) in 32 ballast tank sediments collected during 2001-2003 from ships entering the Great Lakes or Chesapeake Bay and subsequently archived. Seventy-three dinoflagellates were fully identified to species level by this metagenomic approach and single-cell polymerase chain reaction (PCR)-based sequencing, including 19 toxic species, 36 harmful algal bloom (HAB) forming species, 22 previously unreported as producing cysts, and 55 reported from ballast tank sediments for the first time (including 13 freshwater species), plus 545 operational taxonomic units (OTUs) not fully identified due to a lack of reference sequences, indicating tank sediments are repositories of many previously undocumented taxa. Analyses indicated great heterogeneity of species composition among samples from different sources. Light and scanning electron microscopy and single-cell PCR sequencing supported and confirmed results of the metagenomic approach. This study increases the number of fully identified dinoflagellate species from ballast tank sediments to 142 (> 50% increase). From the perspective of ballast water management, the high diversity and spatiotemporal heterogeneity of dinoflagellates in ballast tanks argues for continuing research and stringent adherence to procedures intended to prevent unintended introduction of non-indigenous toxic and HAB-forming species.
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Aim: To develop a standardized, quantitative method for mapping cumulative impacts of invasive alien species on marine ecosystems. Location: The methodology is applied in the Mediterranean Sea but is widely applicable. Methods: A conservative additive model was developed to account for the Cumulative IMPacts of invasive ALien species (CIMPAL) on marine ecosystems. According to this model, cumulative impact scores are estimated on the basis of the distributions of invasive species and ecosystems, and both the reported magnitude of ecological impacts and the strength of such evidence. In the Mediterranean Sea case study, the magnitude of impact was estimated for every combination of 60 invasive species and 13 habitats, for every 10x10 km cell of the basin. Invasive species were ranked based on their contribution to the cumulative impact score across the Mediterranean. Results: The CIMPAL index showed strong spatial heterogeneity. Spatial patterns varied depending on the pathway of initial introduction of the invasive species in the Mediterranean Sea. Species introduced by shipping gave the highest impact scores and impacted a much larger area than those introduced by aquaculture and the Suez Canal. Overall, invasive macroalgae had the highest impact among all taxonomic groups. These results represent the current best estimate of the spatial variation in impacts of invasive alien species on ecosystems, in the Mediterranean Sea. Main Conclusions: A framework for mapping cumulative impacts of invasive alien species was developed. The application of this framework in the Mediterranean Sea provided a baseline that can be built upon with future improved information. Such analysis allows the identification of hotspots of highly impacted areas, and prioritization of sites, pathways, and species for management actions.
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Transportation and translocation of non-native species by ships through ballast water is one of the current issues the shipping industry is trying to address. The Ballast Water Convention is nearing full ratification after which treatment of ballast water will become mandatory for most of the trading merchant vessel categories. Ballast water management systems employing various technologies are commercially available but at high costs. Economics apart, the efficiency of these technologies and realistic ways to ensure compliance with stricter requirements of some Administrations are issues that need to be focussed upon. With the report of the Environmental Protection Agency as an assessment reference, this paper reviews the treatment technologies. Juxtaposing reports of Lloyd’s Register on the status, a concise overview of the technologies has been projected. A sustainable ballast water management based on data and assessments is proposed. The management must be extended to both shore and on-board platforms for practices, treatment, sampling, testing, and recycling. An exemplar system harvesting shipboard waste heat is projected as a route for thermal treatment in combination with technologies showing potential for optimized ballast water management.
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The introduction of invasive species, which often differ functionally from the components of the recipient community, generates ecological impacts that propagate along the food web. This review aims to determine how consistent the impacts of aquatic invasions are across taxa and habitats. To that end, we present a global meta-analysis from 151 publications (733 cases), covering a wide range of invaders (primary producers, filter collectors, omnivores and predators), resident aquatic community components (macrophytes, phytoplankton, zooplankton, benthic invertebrates and fish) and habitats (rivers, lakes and estuaries). Our synthesis suggests a strong negative influence of invasive species on the abundance of aquatic communities, particularly macrophytes, zooplankton and fish. In contrast, there was no general evidence for a decrease in species diversity in invaded habitats, suggesting a time lag between rapid abundance changes and local extinctions. Invaded habitats showed increased water turbidity, nitrogen and organic matter concentration, which are related to the capacity of invaders to transform habitats and increase eutrophication. The expansion of invasive macrophytes caused the largest decrease in fish abundance, the filtering activity of filter collectors depleted planktonic communities, omnivores (including both facultative and obligate herbivores) were responsible for the greatest decline in macrophyte abundance, and benthic invertebrates were most negatively affected by the introduction of new predators. These impacts were relatively consistent across habitats and experimental approaches. Based on our results, we propose a framework of positive and negative links between invasive species at four trophic positions and the five different components of recipient communities. This framework incorporates both direct biotic interactions (predation, competition, grazing) and indirect changes to the water physicochemical conditions mediated by invaders (habitat alteration). Considering the strong trophic links that characterize aquatic ecosystems, this framework is relevant to anticipate the far-reaching consequences of biological invasions on the structure and functionality of aquatic ecosystems. © 2015 John Wiley & Sons Ltd.
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The most effective way to manage species transfers is to prevent their introduction via vector regulation. Soon, international ships will be required to meet numeric ballast discharge standards using ballast water treatment (BWT) systems, and ballast water exchange (BWE), currently required by several countries, will be phased out. However, there are concerns that BWT systems may not function reliably in fresh and/or turbid water. A land-based evaluation of simulated 'BWE plus BWT' versus 'BWT alone' demonstrated potential benefits of combining BWE with BWT for protection of freshwater ecosystems. We conducted ship-based testing to compare the efficacy of 'BWE plus BWT' versus 'BWT alone' on voyages starting with freshwater ballast. We tested the hypotheses that there is an additional effect of 'BWE plus BWT' compared to 'BWT alone' on the reduction of plankton, and that taxa remaining after 'BWE plus BWT' will be marine (low risk for establishment at freshwater recipient ports). Our study found that BWE has significant additional effect on the reduction of plankton, and this effect increases with initial abundance. As per expectations, 'BWT alone' tanks contained higher risk freshwater or euryhaline taxa at discharge, while 'BWE plus BWT' tanks contained mostly lower risk marine taxa unlikely to survive in recipient freshwater ecosystems.
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A brief overview is given of current applications of flow cytometry (FCM) in marine phytoplankton research. This paper presents a selection of highlights and various technical and analytical problems we encountered during the past 10 years. In particular, the conversion of the relative values obtained in terms of size and fluorescence applying FCM to quantitative estimates of cell size, pigment concentration, genome size etc., is addressed. The introduction of DNA -cell-cycle analysis made easily assessable by flow cytometry has been of great impor tance, allowing in situ measurement of species specific growth rates. Key questions in ecology such as factors determining the wax and wane of phytoplankton bloom can now be better answered in terms of species specific growth and mortality. Finally, flow cytometry provides detailed information of the physiological status of the individual algal cells. New staining methods enable us to distinguish between viable and non-viable cells and so will help us to elucidate the importance of 'automortality' in aquatic ecosystems.
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A shipboard study was conducted aboard the cruise ship Coral Princess during a scheduled cruise from San Pedro, CA, USA to Vancouver, British Columbia, Canada. The investigation involved three members of the global TestNet group, with experience in certification testing of ballast water treatment systems (BWTS) designed to eliminate entrained invasive species. A UV-based ballast water treatment system had been employed aboard the vessel for more than 10 years. A variety of established and experimental assessment techniques were employed, both aboard the ship and following shipment of samples via road (5 days) and air (7 days) to remote laboratories. The study was designed to compare the performance of different techniques in assessing BWTS compliance with international regulations, and to test the feasibility of compliance assessment by Port State Control internationally using different laboratories. Overall, biological end-points showed effective treatment of ballast water as judged by the percentage removal (mortality) of organisms in treated samples. Sample transport indicated generally good potential for ‘off-site’ sample analysis and displayed a possible latent effect of treatment as judged by a decline in photosynthetic yield associated with delayed analysis.
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Understanding the implications of different management strategies is necessary to identify best conservation trajectories for ecosystems exposed to anthropogenic stressors. For example , science-based risk assessments at large scales are needed to understand efficacy of different vector management approaches aimed at preventing biological invasions associated with commercial shipping. We conducted a landscape-scale analysis to examine the relative invasion risk of ballast water discharges among different shipping pathways (e.g., Transoceanic, Coastal or Domestic), ecosystems (e.g., freshwater, brackish and marine), and timescales (annual and per discharge event) under current and future management regimes. The arrival and survival potential of nonindigenous species (NIS) was estimated based on directional shipping networks and their associated propagule pressure, environmental similarity between donor-recipient ecosystems (based on salinity and temperature), and effects of current and future management strategies (i.e., ballast water exchange and treatment to meet proposed international biological discharge standards). Our findings show that current requirements for ballast water exchange effectively reduce invasion risk to freshwater ecosystems but are less protective of marine ecosystems because of greater environmental mismatch between source (oceanic) and recipient (freshwater) ecoregions. Future requirements for ballast water treatment are expected to reduce risk of zooplankton NIS introductions across ecosystem types but are expected to be less effective in reducing risk of phytoplankton NIS. This large-scale risk assessment across heterogeneous ecosystems represents a major step towards understanding the likelihood of invasion in relation to shipping networks, the relative efficacy of different invasion management regimes and seizing opportunities to reduce the ecological and economic implications of biological invasions.
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The introduction of invasive marine species into new environments through ships’ ballast water, attached to ships’ hulls and via other vectors has been identified as one of the four greatest threats to the world’s oceans. Different treatment methods have been proposed for onboard ballast water treatment options to reduce this effect, among those also ultraviolet light (UV), ultrasound (US) and ozone (O3) treatments. The literature survey that was carried out during the first phase of the project indicated that all of the methods have potential for ballast water treatment and numerous reports were available presenting the research activities carried out around the world. The technology that has been studied most widely appears to be UV, whereas US seems to have very limited application in terms of ballast water treatment. In addition to single technologies, the combinations of US + UV and UV + hydrogen peroxide (H2O2) were also tested as part of the hurdle experiments. During the first phase, the methods were tested under laboratory both in Finland and the UK. After an evaluation of the laboratory test results, onshore trails were carried out in Tvärminne, Finland, in order to confirm the proper operation of the devices and to obtain information about the efficiency of the treatment options against the organisms in the Baltic Sea marine environment. The effects on phytoplankton and bacteria were not studied. The results from the laboratory trials were partly confusing due to the various scale effects related to the test system and thus the results were difficult to explain. The results from Tvärminne onshore trials, with considerable reliability for UV, varied between 78–100%, for US treatment between 80–99% and for ozone treatment 95– 100% depending on the organism group, flow rate and ozone dosages. The combination of US and UV achieved mortality rates of between 97–100% and the combination of UV + H2O2 between 94–100%. Even in those cases where 100% mortality was observed, the requirements for the maximum allowable number of viable organisms per water volume set by IMO were not necessarily confirmed due to the relatively small sampling volume. It must also be emphasised that only moderate (200–1,600 l/h) flow rates were used. During the trials in the UK, a possible modification of ballast water properties and contents by the treatments was also identified. Ozone treatment causes a significant increase in Redox potential with possible consequences on metal corrosion, coatings and gaskets. However, these effects can be minimised by careful material selection. Costs evaluations were carried out in order to provide rough estimations of treatment costs for each treatment option on two different case study ships. It appears that the costs for treated ballast water varies between 0.045–0.11 €/m3 for UV treatment, for US 0.39–0.43 €/m3 and for ozone 0.20–0.24 €/m3. The effect on the shipping costs due to the treatment varies between 1–14% per voyage for these case study ships. These values represent the cost evaluation for a full-scale application based on the current level of treatment technology available. It is more likely that treatment costs would lower due to technology development. It must be kept in mind that different source and background information has been available for each study and therefore reasonable comparison between the methods is difficult. In most of the cases, the treatment processes are not predictable due to the different water properties and operational aspects. Therefore, further studies and full-scale trials are required in order to optimise the process conditions for each treatment technology. One option for the testing and evaluation of various treatment methods could be container installations, where treatment processes would be designed for full-scale flow rates and water volumes. This option would also enable different marine environments to be included in the test programme. In addition to the secondary treatment options, primary treatment options, i.e., filters and cyclons, should also be included since many secondary treatment options require primary treatment in order to perform efficiently. In addition to the treatment technologies, the sampling and analysing methods also need to be developed in order to ensure reliable results and easy-to-use samplers for the ship’s crew. The long-awaited guidelines for test and performance specifications adopted in the IMO MEPC 53 meeting in July 2005 standardised the testing procedures and provides technology developers and manufacturers with a uniform approach to the challenge.
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The spread of aquatic invasive species through ballast water is a major ecological and economical threat. Because of this the International Maritime Organization (IMO) set limits to the concentrations of organisms allowed in ballast water. To meet these limits ballast water treatment systems (BWTSs) were developed. The main techniques used for ballast water treatment are Ultraviolet radiation (UV) and electrochlorination (EC). In this study, phytoplankton re-growth after treatment was followed for six BWTSs. Natural plankton communities were treated and incubated for 20 days. Growth, PSII efficiency and species composition were followed. The three UV systems all showed similar patterns of decrease in phytoplankton concentrations followed by re-growth. The two EC and the chlorine dioxide systems showed comparable results. However, UV and chlorine-based treatment systems showed significantly different responses. Overall, all BWTSs reduced phytoplankton concentrations to below the IMO limits, which represents a reduced risk of aquatic invasions through ballast water.
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A good understanding of the mechanisms and magnitude of the impact of invasive alien species on ecosystem services and biodiversity is a prerequisite for the efficient prioritisation of actions to prevent new invasions or for developing mitigation measures. In this review, we identified alien marine species that have a high impact on ecosystem services and biodiversity in European seas, classified the mechanisms of impact, commented on the methods applied for assessing the impact and the related inferential strength, and reported on gaps in available information. Furthermore, we have proposed an updated inventory of 87 marine species in Europe, representing 13 phyla, which have a documented high impact on ecosystem services or biodiversity. Food provision was the ecosystem service that was impacted by the greatest number of alien species (in terms of both positive and negative impacts). Following food provision, the ecosystem services that were negatively affected by the highest number of alien species were ocean nourishment, recreation and tourism, and lifecycle maintenance, while the ecosystem services that were most often positively impacted were cognitive benefits, water purification, and climate regulation. In many cases, marine aliens were found to impact keystone/protected species and habitats. Thirty percent of the assessed species had an impact on entire ecosystem processes or wider ecosystem functioning, more often in a negative fashion. Forty-nine of the assessed species were reported as being ecosystem engineers, which fundamentally modify, create, or define habitats by altering their physical or chemical properties. The positive impacts of alien species are probably underestimated, as there is often a perception bias against alien species. Among the species herein assessed as high-impact species, 17 had only negative and 7 only positive impacts; for the majority (63 species), both negative and positive impacts were reported; the overall balance was often unknown. Although there is no doubt that invasive species have modified marine ecosystems, evidence for most of the reported impacts is weak, as it is based on expert judgement or dubious correlations, while only 13% of the reported impacts were inferred via manipulative or natural experiments. A need for stronger inference is evident, to improve our knowledge base of marine biological invasions and better inform environmental managers.
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Rigorous evaluation of ballast water management systems (BMWSs) at land-based test facilities requires that water used in testing meets minimum concentrations of dissolved and particulate material, for example, using the criteria in the U.S Environmental Technology Verification (ETV) Program’s protocol for testing of BWMSs. Here, uptake water (“challenge water”) can be augmented with compounds to meet these benchmarks. In this study, we evaluated materials used to supplement dissolved organic matter (DOM), particulate organic matter (POM), and mineral matter (MM) used to achieve challenge water criteria. To determine the additives’ contributions to DOM and POM pools, the mass yields of Camellia sinesis (decaffeinated iced tea) extract and humic matter were calculated at different temperature and salinities. Additionally, the response of ambient organisms to these additives was measured in mesocosm experiments, in which changes in organism concentrations were measured after a 5-d holding time. Living organisms were grouped into three size classes: ≥50 μm (nominally zooplankton), ≥10 to <50 μm (nominally protists), and <10 μm (measured as culturable, aerobic, heterotrophic bacteria). Significant differences in concentrations between control and treatment mesocosms after 5 d were not detected for organisms in the ≥10 to <50 μm or the ≥50 μm size classes. However, bacterial concentrations increased significantly in mesocosms augmented with exogenous materials. Thus, direct impacts (or indirect impacts through increased bacterial concentrations) were not apparent among organisms in the two largest size classes. Finally, a literature review of DOM, POM, and total suspended solids concentrations in coastal waters was conducted. It revealed that the challenge water concentrations outlined in the ETV protocol are at the middle to upper range of concentrations observed in coastal and estuarine water. The mean DOM and POM concentrations in this data set typically fell short of the ETV minimum requirements, and more data are needed to fully assess the suitability of these requirements.
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Today global shipping transports over 90 % of the world’s overseas trade and trends anticipate that it will continue to play an increasing role world-wide. Shipping operations inevitably include also pressures on natural environments. The most recent waterborne threat is the transfer of harmful aquatic organisms and pathogens with ballast water and sediments releases, which may result in harmful effects on the natural environment, human health, property and resources globally. The significance of the ballast water issue was already addressed in 1973 by the International Maritime Organization (IMO) as the United Nations specialised agency for the regulation of international maritime transport at the global scale. Committed work by many experts, scientists, politicians, IGOs and NGOs at IMO resulted in the adoption if the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) in February 2004, which is now to be ratified and implemented. Work on ballast water management issues has also shown to be very complex, hence there are no simple solutions. Nevertheless, the BWM Convention represents a globally uniform framework for the implementation of ballast water management measures, and different supporting tools like risk assessment and decision support systems have been developed to support its efficiency. In this chapter the reader is introduced to various ballast water issues and responses to it. The intention of this book and the overview of its content is also presented.
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A good understanding of the mechanisms and magnitude of the impact of invasive alien species on ecosystem services and biodiversity is a prerequisite for the efficient prioritisation of actions to prevent new invasions or for developing mitigation measures. In this review, we identified alien marine species that have a high impact on ecosystem services and biodiversity in European seas, classified the mechanisms of impact, commented on the methods applied for assessing the impact and the related inferential strength, and reported on gaps in available information. Furthermore, we have proposed an updated inventory of 87 marine species in Europe, representing 13 phyla, which have a documented high impact on ecosystem services or biodiversity.
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Seasonal variation in POC and DOC was measured in the Marsdiep tidal inlet of the Wadden Sea from March 1978 to June 1981, and compared with tidal variation.A POC peak was coincident with the phytoplankton peak (except for 1981), whereas a DOC peak occurred about one month later indicating autolysis and degradation of phytoplankton rather than excretion as the main source of this DOC. DOC production calculated from the spring increase amounted to 4.2 mg C·1−1 or about 40% of the annual phytoplankton primary production in the area. This means that a large part of the phytoplankton production is not used directly by primary consumers but is converted into DOC.Tidal variation in DOC was correlated with salinity, pointing to a fresh water source for the bulk of it. POC was correlated with suspended matter content and phaeopigment, and slightly less with chlorophyll. Compared with the seasonal variation, tidal variation in chlorophyll and temperature was relatively small, but large in POC, DOC, suspended matter and salinity.Although import of POC and export of DOC through the Marsdiep inlet is large on an annual base, the transport cannot be measured directly because of the variability and precision limits of the measurements and as differences in content between ebb and flood current are only 15 and 5% of the POC and DOC content, respectively.
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Diatom and dinoflagellate species that are not endemic to a region can be inadvertently introduced when their resistant resting stages are discharged with the ballast-tank waters and sediments of bulk cargo vessels. A survey of 343 cargo vessels entering 18 Australian ports showed that 65% of ships were carrying significant amounts of sediment on the bottom of their ballast tanks. All of these samples contained diatoms, including species that are not endemic to Australian waters. Diatom resting spores, especially of Chaetoceros, were also detected. Dinoflagellate resting spores (cysts) were present in 50% of the sediment samples. Of the 53 cyst species identified, 20 (including Diplopelta, Diplopsalopsis, Gonyaulax, Polykrikos, Protoperidinium, Scrippsiella and Zygabikodinium spp.) were successfully germinated to produce viable cultures. Such diversity of diatom and dinoflagellate species in ships' ballast water suggests that the apparent cosmopolitanism of many coastal phytoplankton species may be due partly to the global transport of seawater ballast. Of considerable concern was the detection in 16 ships of cysts of the toxic dinoflagellates Alexandrium catenella, Alexandrium tamarense and Gymnodinium catenatum. One single ballast tank was estimated to contain >300 million viable A.tamarense cysts, some of which were successfully germinated in the laboratory to produce toxic cultures. These toxic dinoflagellate species, which can contaminate shellfish with paralytic shellfish poisons, pose a serious threat to human health and the aquaculture industry. Ballast-water quarantine measures recently introduced in Australia are discussed. Mid-ocean exchange of ballast water is only partially effective in removing dinoflagellate cysts which have settled to the bottom of ballast tanks. The present work indicates that the most effective measure to prevent the spreading of toxic dinoflagellate cysts via ships' ballast water would be to avoid taking on ballast water during dinoflagellate blooms in the water column of the world's ports.
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Different stages of the automortality in phytoplankton have been studied applying flow cytometry. These stages are, in order of expression: (1) compromised cell membranes, (2) degradation of the photosynthetic pigments and reduction of the photosynthetic activity, (3) fragmentation of the genomic DNA. The integrity test of the cell membranes is based on the inability of the DNA-specific stain SYTOX Green to pass into cells with intact plasma membranes. The reduction in photosynthetic activity was examined by sorting C-labelled phytoplankton cells differing in viability. Finally, DNA fragmentation was traced by measuring changes in genomic DNA. The different phytoplankton species tested showed a great variety in response when grown under the same conditions, but there was also considerable intraspecific variation. Unstained cells, fully stained cells (equivalent to full staining of genomic DNA in fixed cells) and cells with intermediate fluorescence signal occurred together within the same culture. The photosynthetic activity in cells with a reduced viability dropped by as much as 60% relative to that of the viable cells. In the subsequent stage, when photosynthetic pigments were fully degraded, this value dropped further to around 10%. Cells in this stage also showed subdiploidy as a result of genome fragmentation. Field tests using samples of phytoplankton collected in the North Atlantic Ocean (40° N, 23° W) during spring showed staining properties similar to those found in cultures grown at suboptimal growth conditions. The percentage of non-viable cells varied considerably (ranging from 5% to 60%) between the various phytoplankton groups present. The lowest value was observed for Synechococcus, but some pico-eukaryotes showed percentages as high as 60%. Moreover, the viability varied with depth (light level) and over a light–dark cycle. The present findings suggest the existence of a (genetically based) uniform process of automortality in phytoplankton. Non-viable cells are a substantial component of the oceanic phytoplankton, affecting the food-web structure and species succession.
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During May–December 1990 and March–May 1991, 546 foreign ocean-going vessels entered the Laurentian Great Lakes and upper St. Lawrence River, areas protected by the Great Lakes Ballast Water Control Guidelines. Between 88 and 94% of the vessels exchanged their ballast water with seawater as required by the guidelines. Living representatives of 11 invertebrate phyla were sampled from ballast tanks. Between 14 and 33% of ships that exchanged freshwater ballast in midocean carried living freshwater-tolerant zooplankton at the time of entry to the Seaway, although these included many taxa already found in the Great Lakes. Four freshwater-tolerant zooplankton species that were identified as living specimens in ballast water have apparently not been recorded from the Great Lakes. Voluntary ballast water controls reduced but did not eliminate the risk of species invasion, since some ships did not comply with the guidelines, and even ships that did exchange ballast water could introduce viable freshwater-tolerant organisms into the Great Lakes. About half of the ballast water carried into the Seaway by ocean-going vessels and lakers each year originates from the St. Lawrence River, portions of which are not yet protected by any ballast controls.
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Many ballast water sampling programmes were undertaken in the past to document the number of individuals and variety of species arriving with ships. As no standard ballast water sampling tool exists various sampling devices were used during these studies. When sampling ballast water for compliance control with the Ballast Water Management Convention prepared by the International Maritime Organization a sampling device is needed which documents the number of organisms per water volume discharged. For organisms above 50 microns (in minimum dimension) less than 10 organisms per cubic meter of water are acceptable in the ballast water discharged. Further, ballast water samples need to be taken to assess the efficacy of ballast water treatment systems. As a result more than 1,000 liters of water need to be sampled – and this needs to be carried out multiple times as more than one sampling point, several replicates and various sampling occasions are required. This contribution describes a new sampling device for this ballast water sampling purpose.
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In an assessment of non-indigenous species transported by international ship traffic to German waters, commissioned by the German Federal Environmental Agency, the survival of tropical plankton organisms in ballast water was studied by accompanying a container vessel on its 23-day voyage from Singapore to Bremerhaven in Germany. Two tanks, one filled off Singapore and the other off Colombo, Sri Lanka, were monitored for their phyto- and zooplankton content by daily sampling. As already reported in previous studies, species abundance and diversity, especially of zooplankton, decreased sharply during the first days, and only a few specimens survived the whole cruise. The contents of the Colombo tank, however, changed dramatically during the last week. The harpacticoid copepod, Tisbe graciloides, increased its abundance by a factor of 100 from 0.1 to 10 ind. l-1 within a few days. This is the first time that a ballast water organism has been found to multiply at such a high rate. Opportunistic species such as Tisbe are apparently able to thrive and propagate in ballast water tanks under certain conditions. Ballast water tanks may thus serve as incubators for certain species depending on their characteristics.
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Ballast water of ships has been recognized as a major vector for the unintentional transfer of exotic aquatic organisms between and within many parts of the world. Studies in several European ports have shown that most of the ballast water discharged originates from nearby sea areas indicating the importance of secondary introductions. However, the patterns of interregional transfer of exotic species within Europe remain largely unknown. The present study examined the transport of phyto- and zooplankton organisms in the ballast water to assess the potential for the transport of invasive aquatic species between the Baltic Sea and the open Atlantic coast of Europe. Six potentially toxic phytoplankton species were found in the ballast water examined. In four ballast water sampling trials no significant changes in abundance of both phyto- and zooplankton organisms were observed during first 3-4 days of experiment. Even in the end of the longest sampling trial (15 days) millions of plankton organisms were found. The results obtained indicate the importance of interregional European shipping in the dispersal of exotic plankton organisms.
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Invasive aquatic species discharged through ballast water is one of the most serious problems posed nowadays in the marine environment. This review paper summarizes the available technologies applied for ballast water treatment. These technologies can be either port-based or ship-based, with the latter being easier to implement. Special emphasis was given to onboard treatment methods, which can be categorized as physical separation, mechanical or chemical methods. The efficiency of the methods, as well as the capacity of application and the target microorganisms were compiled and are presented in this review. Copyright © 2009 Society of Chemical Industry
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Ballast water has been the primary vector of nonindigenous species (NIS) to the Laurentian Great Lakes over the past 45 years. Although ballast water exchange regulations were implemented in 1993 to reduce propagule loads, new NIS continue to be discovered. A possible explanation for this trend is the importance of alternative vectors, such as residual ballast of ships claiming "no ballast on board". We investigate resting stages of invertebrates in residual ballast sediments of transoceanic ships as a possible vector of NIS to the Great Lakes. To model the introduction effort potentially associated with this vector, we collected sediment samples from 39 ships entering the Great Lakes and measured the density, viability, and species richness of resting stages contained therein. Viable resting stages of NIS were found in 32% of ships, at a mean density of 3.0 � 105�ship�1. Temperature, salinity, and removal of eggs from sediment during incubation had a significant impact on total abundance and species richness of hatched taxa. A total of 21 NIS were identified, consisting exclusively of rotifers and cladocerans. Salinity of residual ballast water and geographic region of ballast uptake were predictive variables for profiling invasion risk due to ships, although explained variability was low.
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Marine invasive species are currently recognized as one of the most significant threats to global biodiversity. Marine bioinvasions are more likely in the Mediterranean Sea because of its wide temperature range, degraded habitats, historical and high volume of shipping traffic, and high occurrence of aquaculture. One of the main vectors of marine introductions globally and Mediterranean-wide is commercial shipping. Of the 3,000–4,000 species transferred around the world via commercial vessels, approximately 30% of these species may have been redistributed in the Mediterranean. Ships and marine invasive species arriving in the Mediterranean are mainly from temperate to cold-water regions. Standardized research and management approaches between countries are required to address the threat of ballast water borne marine invasives on a global scale. Regionally, a Mediterranean program involving the different states is currently needed to develop a common line of research and management operations. Key wordsballast water–marine introductions–invasive species–Mediterranean Sea–shipping–standardized research and management
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A principal mechanism for the transfer of non-indigenous species among aquatic ecosystems has been through the movement of ships’ ballast water. To date, most ballast water studies have focused on the transoceanic movement of organisms while ignoring the potential for spread by intracoastal traffic. This study measured the transfer of estuarine and coastal species by domestic ship traffic between Somerset, Massachusetts and Norfolk, Virginia, U.S.A. Plankton diversity and abundance in the ballast water of a coal carrier at the beginning and end of seven replicate voyages were estimated. These data, collected over a 1-year period, were used to (1) characterize plankton assemblages in the ballast water, (2) assess survivorship of ballasted organisms for the voyages by comparing initial and final abundances, and (3) test for differences in survival as a function of voyage or taxonomic group. A diverse assemblage of organisms was transported intracoastally that was dominated by dinoflagellates, diatoms and copepods. In four of seven voyages, total abundance declined significantly over the 36-h journey; however, considerable within- and among-voyage variation in numerical response among major taxonomic groups was observed. Despite a general decline in abundance, millions of organisms nevertheless survived each voyage and were released into the receiving harbor. These data indicate that ballast water carried by domestic ships is potentially an important vector for transferring aquatic non-indigenous and native nuisance species. Thus, future management decisions concerning ballast water transport should consider the role of domestic traffic in promoting invasions.
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Ballast water management systems (BWMS) are rigorously tested in land-based and shipboard settings, according to requirements outlined in the former G8 Guidelines of the International Maritime Organization (IMO). Noting doubts that the water conditions to challenge BWMS as stated in G8 may not be challenging enough to represent all port water conditions worldwide, this guideline was revised at IMO in 2016 to make G8 better fit for purpose, and the instrument was made mandatory as BWMS Code in 2018. This contribution summarizes the intake water conditions we observed during >300 samples taken during >100 shipboard BWMS performance tests during 12 years. The data presented include the abiotic water conditions (i.e., temperature, salinity, TSS and POC) and the counts of viable organisms in the two size classes addressed by the Ballast Water Performance Standard (Regulation D-2) of the IMO Ballast Water Management Convention. Our data showed how close IMO challenge water requirements are to what was observed in nature. In addition, we compared our results with the test requirements of the US BWMS test protocol. Based on our results, further recommendations for BWMS Code improvements were included. These recommendations refer to the challenge water conditions in performance tests of BWMS, which were kept unchanged during the G8/BWMS Code revision(s). One of our recommendations is to increase the required concentration of zooplankton organisms in the challenge water during shipboard tests to better reflect the natural zooplankton concentrations.
Article
Ballast Water Managements Systems (BWMS) installed on vessels may use Active Substances (AS) to inactivate organisms. This paper provides new insights in the global issue of noxious Disinfection By-Products (DBP) produced with primarily oxidant-based BWMS, and the risk assessment for workers, including port State control officers, while performing tasks on a vessel that involve exposure to treated ballast water. The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection Ballast Water Working Group (GESAMP-BWWG) plays a role in the certification process of BWMS that make use of AS evaluating potential negative effects. All BWMS that passed GESAMP-BWWG Final Approval until mid 2019 were analyzed providing an overview of chemicals in the treated ballast water before and after neutralization. The ballast tank cleaning scenario, the sampling scenario, and the ballast tank inspection scenario all showed elevated human health risks using the Derived Minimal Effect Levels approach. The most critical exposure occurs in the ballast tank cleaning scenario through the inhalation of volatile DBP, such as tribromomethane. This substance may cause acute effects such as headache, dizziness and also has carcinogenic properties. The two risk reducing options available in the GESAMP BWWG Tier 2 calculations were compared, one being mitigation measures such as protective gloves and coveralls, the other option is taking into account a time correction factor. The results showed that the trihalomethanes in air are most problematic, however, there is a possibility that the calculated values may be overestimated as generally worst case assumptions were used.
Article
The International Ballast Water Management (BWM) Convention entered into force in September 2017. In the convention, the International Maritime Organization (IMO) required two options: ballast water exchange (BWE) standard D-1, and ballast water performance standard D-2 which required ballast water treatment systems (BWTSs). We explored the impact of policy on the utilization of BWTSs by examining IMO Type Approval records and country-level databases in the United States and Australia. In December 2018, 65 BWTSs had IMO Type Approval and 13 had US Coast Guard approval. The majority of vessels with BWTSs had either electrolytic or UV treatment systems (Australia, 84%; USA, 89%). From 2016 to 2017, both countries experienced an increase in the percentage of vessels with BWTS, vessels utilizing BWTS, and total ballast discharge treated with BWTS. Based on this analysis, shipowners appear to primarily rely on two treatment technologies in Australia and the United States to meet compliance.
Article
Propagule pressure plays a key role in the successful establishment of introduced species. Explaining invasion patterns, predicting future invasions and reducing invasion rates are priority areas of research and management, especially in marine systems, which need more detailed correlates and invasion predictors. The commercial maritime shipping fleet is the most prolific long distance anthropogenic transfer mechanism (vector) of marine non‐indigenous species on a global scale, causing invasions of coasts by a wide diversity of organisms. Although most vessel arrivals provide an opportunity for organism introductions, there are often substantial differences among ship types—in both their “morphological traits” (structural design) and “behavioural ecology” (cargo delivery model and operational tempo)—that influence propagule delivery by ballast water and biofouling, the two dominant sources or sub‐vectors for ship‐mediated species transfers. We reviewed ship specialization and its implications for marine invasion and vector management. First, we identified factors that affect ship‐mediated propagule delivery characteristics (number, identity, diversity and quality/condition), classifying these as ship type independent or dependent factors. Second, we compared the relevance of these factors for both ballast water and biofouling. Third, we estimated and compared the magnitude of several key factors affecting propagule delivery among seven major ship types. Typical voyage speed varies by 74% and port residence time varies sixfold among ship types. Similarly, typical ballast water discharge varies by an order of magnitude among ship types. These and other ship type dependent factors affect propagule delivery characteristics, resulting in uneven magnitude of species transfer among ship types. Policy implications . Variation among commercial ship types is rarely integrated into analyses of marine bioinvasions and proxy measures of propagule delivery. Their inclusion may lead to more robust explanation, prediction and management of marine invasions. Risk analyses that account for differences among ship types and prevailing traffic directionality will likely offer greater insight than null models, which treat ships equally. Furthermore, ballast treatment technologies and hull husbandry may advance to reduce species transfers more effectively when tailored for different ship types, recognizing the variation and operational constraints (that affect propagule delivery) among the diverse range of ship types.
Article
The biology of vessels´ ballast water needs to be analysed for several reasons, one of these being performance tests of ballast water management systems. This analysis includes a viability assessment of phytoplankton. To overcome logistical problems to get algae sample processing gear on board of a vessel to document algae viability, samples may be transported to land-based laboratories. Concerns were raised how the storage conditions of the sample may impact algae viability over time and what the most appropriate storage conditions were. Here we answer these questions with a long-term algae viability study with daily sample analysis using Pulse-Amplitude Modulated (PAM) fluorometry. The sample was analysed over 79 days. We tested different storage conditions: fridge and room temperature with and without light. It seems that during the first two weeks of the experiment the viability remains almost unchanged with a slight downwards trend. In the continuing period, before the sample was split, a slightly stronger downwards viability trend was observed, which occurred at a similar rate towards the end of the experiment. After the sample was split, the strongest viability reduction was measured for the sample stored without light at room temperature. We concluded that the storage conditions, especially regarding temperature and light exposure, have a stronger impact on algae viability compared to the storage duration and that inappropriate storage conditions reduce algal viability. A sample storage time of up to two weeks in a dark and cool environment has little influence on the organism viability. This indicates that a two week time duration between sample taking on board a vessel and the viability measurement in a land-based laboratory may not be very critical.
Article
Until now, the purpose of ballast water sampling studies was predominantly limited to general scientific interest to determine the variety of species arriving in ballast water in a recipient port. Knowing the variety of species arriving in ballast water also contributes to the assessment of relative species introduction vector importance. Further, some sampling campaigns addressed awareness raising or the determination of organism numbers per water volume to evaluate the species introduction risk by analysing the propagule pressure of species. A new aspect of ballast water sampling, which this contribution addresses, is compliance monitoring and enforcement of ballast water management standards as set by, e.g., the IMO Ballast Water Management Convention. To achieve this, sampling methods which result in representative ballast water samples are essential. We recommend such methods based on practical tests conducted on two commercial vessels also considering results from our previous studies. The results show that different sampling approaches influence the results regarding viable organism concentrations in ballast water samples. It was observed that the sampling duration (i.e., length of the sampling process), timing (i.e., in which point in time of the discharge the sample is taken), the number of samples and the sampled water quantity are the main factors influencing the concentrations of viable organisms in a ballast water sample. Based on our findings we provide recommendations for representative ballast water sampling.
Article
The latest research continues to show that the ballast water issue is very complex, which makes it very challenging to manage. In 2004, the International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) was adopted to globally harmonize action against the transfer of harmful aquatic organisms and pathogens via ships’ ballast water and related sediments. Analyses of the BWM Convention requirements, conducted through different research projects mainly aiming to provide support for the implementation of the BWM Convention, have shown that there are different steps countries need to take and that there are still some open issues which need to be solved. This paper presents some of the main issues identified and the core theoretical and applied measures required to solve these issues, with the aim to support more efficient and coordinated implementation of the BWM Convention requirements in EU seas. The approaches recommended here for the EU may be universally interesting for similar application in other areas of the world.
Article
The patented technology of a High Gradient Magnetic Separation (HGMS)-Ultraviolet (UV) composite process was used to treat ballast water. Staphylococcus aureus (S. aureus) was selected as the reference bacteria. After treatment by the HGMS-UV process, the concentration of S. aureus on the log 10 scale was lower than 2 at different flow rates, S. aureus suffered the most serious damage, and K+ leakage of the bacteria was 1.73 mg/L higher than separate 60 min UV irradiation (1.17 mg/L) and HGMS (0.12 mg/L) processes. These results demonstrated that the HGMS-UV composite process was an effective approach to treat ballast water. Further, the HGMS process had synergistic action on the subsequent UV irradiation process and accelerated cell membrane damage. Meanwhile, the results of superoxide dismutase (SOD) activities of bacteria and DNA band analyses indicated that the inactivation mechanisms were different for HGMS and UV irradiation.
Article
The patented technology of a High Gradient Magnetic Separation (HGMS)-Ultraviolet (UV) composite process was used to treat ballast water. Staphylococcus aureus (S. aureus) was selected as the reference bacteria. After treatment by the HGMS-UV process, the concentration of S. aureus on the log 10 scale was lower than 2 at different flow rates, S. aureus suffered the most serious damage, and K(+) leakage of the bacteria was 1.73mg/L higher than separate 60min UV irradiation (1.17mg/L) and HGMS (0.12mg/L) processes. These results demonstrated that the HGMS-UV composite process was an effective approach to treat ballast water. Further, the HGMS process had synergistic action on the subsequent UV irradiation process and accelerated cell membrane damage. Meanwhile, the results of superoxide dismutase (SOD) activities of bacteria and DNA band analyses indicated that the inactivation mechanisms were different for HGMS and UV irradiation.
Article
In this paper, invasive marine species in medium-salinity ballast water were inactivated using OH generated from a strong ionization discharge. The OH is determined by the concentration of oxygen active species combined with the effects of water jet cavitation. The results indicated that the OH concentration reached 7.62 μM, within 1 s, which is faster and higher than in conventional AOP methods. In a pilot-scale OH ballast water system with a capacity of 10 m(3)/h, algae were inactivated when CT value was 0.1 mg min/L with a contact time only 6 s. The viable and nonviable cells were determined using SYTOX Green nucleic acid stain and Flow cytometry. As a result, the OH treatment could be completed during the process of conveying the ballast water. In addition, the concentrations of relevant disinfection by-products (DBPs), such as trihalomethanes (THMs), haloacetic acids (HAAs), and bromate, were less than that required by the World Health Organization's drinking water standards, which suggest that the discharged ballast water posed no risks to the oceanic environment. Nevertheless, for conventional ozonation and electrolysis methods, the ballast water should be treated only in the treated tanks during the ship's voyage and form higher level DBPs.
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In this chapter we focus on ballast water management systems (BWMS) which are currently in use as well as treatment approaches manufacturers have chosen for the development of future BWMS. The main purpose of this review is to identify the current availability of BWMS technologies worldwide. Until January 2014 we brought together information of 104 different BWMS. To achieve the ballast water discharge standards, different water treatment technologies are used, mostly in combination, and applied in different stages of the ballasting process. In general, the treatment processes can be split in three stages, i.e., pre-treatment, treatment and residual control (neutralisation). Among the 104 BWMS identified, 100 apply their treatment at the uptake, some of those BWMS require also a treatment during ballast water discharge (in-line treatment) and three BWMS apply treatment only during the voyage (in-tank treatment). The majority of BWMS use filtration or a combination of hydrocyclone and filtration as pre-treatment separation step. The dominating treatment processes are to use an active substance, mostly generated on board by electrolysis/electrochlorination. The second most frequent treatment process is UV. BWMS to be installed for operation on vessels need to be type approved by a state. By the writing of this chapter more than 30 BWMS were type approved. It should be noted that the development of BWMS is a very dynamic market with newly proposed BWMS appearing almost on a monthly basis. The chapter also outlines how BWMS are applied on vessels, their capacities and installation requirements, which BWMS were type approved, and what projected global market for BWMS may exist. A recent calculation on the estimated value of the global market for purchasing and installing BWMSs resulted in an estimated turn-over of possibly $50 '74 billion. The chapter ends with a list of manufacturers, commercial names of their BWMS, applied treatment technologies used and links to BWMS web pages where available.
Article
A newly developed modulation fluorometer is described which employs repetitive 1 μs Xe-flashes for excitation light. Similar to the standard PAM Chlorophyll Fluorometer, which uses 1 μs LED pulses for measuring light, the integrated measuring light intensity is sufficiently low to monitor the dark-fluorescence level, Fo. The maximal fluorescence yield, Fm, can be determined with high selectivity upon application of a saturating light pulse. The Xe-PAM displays exceptionally high sensitivity, enabling quenching analysis at chlorophyll concentrations as low as 1 μg/l, thus allowing to assess photosynthesis of phytoplankton in natural waters like lakes, rivers and oceans. Due to high flexibility in the choice of excitation and emission wavelengths, this system also provides the experimental basis for a thorough study of fluorescence and photosynthesis properties of various algae classes with differing antenna organisation. By appropriate modifications, the instrument may as well be used to measure with great sensitivity and selectivity other types of fluorescence (e.g. NADPH-fluorescence), as well as light-scattering and absorbance changes.
Article
The movement and release of non-indigenous species (NIS) in ship ballast water is a global threat to the conservation of native aquatic species and habitats. One key to successful NIS establishment in coastal waters is propagule pressure – the size and frequency of NIS inoculations. We estimated propagule pressure of high-risk coastal zooplankton delivered in ballast water to Puget Sound, Washington, USA, which receives 7.5×106m3 of ballast water annually. We weighed the relative propagule pressure from domestic and foreign ballast water, in terms of propagule size (number of individuals), frequency of NIS occurrences, and diversity (number of known NIS species). Ship discharge volume was not a good predictor of propagule pressure. Instead route type (domestic or foreign) and ballast water exchange status (exchanged in mid-ocean vs. unexchanged) were much better predictors of propagule supply. Overall, while the diversity of non-indigenous zooplankton was higher in trans-oceanic ballast, the annual discharge of coastal zooplankton propagules to Puget Sound was much greater for ships conducting domestic voyages. These results suggest that intra-coastal ballast water must be further scrutinized as a pathway for NIS introduction, and calls into question regional “common waters” agreements that allow vessels to move ballast without conducting ballast water treatment.
Article
A major vector for unintentional species introductions is international shipping. A wide range of organisms have been transported over long distances in ships' ballast tanks and as hull fouling. Although many desk studies and ship sampling programmes have been carried out, little information is available on changing numbers of individuals in ballast water during voyages. Detailed information could assist in evaluating the dimension of species import and future risks of unintentional species introductions by ballast water. The first European study, organised as a concerted action team and financed by the European Union, carried out several long-term and short-term workshops on board ships undertaking international voyages. The preliminary results from sampling the ballast water of the first four oceangoing workshops of this Concerted Action showed a decrease in numbers of specimens and taxa over time.
Article
Two new fluorochromes, PicoGreen® and SYTOX Green™ stain (Molecular Probes, Inc.), are useful with flow cytometry for quantitative detection of cellular DNA in a variety of marina phytoplankton. The basic instrument configuration of modern low-power flow cytometers (15 mW, 488 nm excitation) is sensitive enough to detect the DNA signal in nearly all of the 121 strains (from 12 taxonomic classes)examined. The major advantages of these dyes over others are 1)suitability for direct use in seawater, 2)green fluorescence emission of the DNA-dye complex (wavelength 525 ± 15 nm) showing no overlap with the autofluorescence of the plankton pigments in the red band, 3) high fluorescence yield of the DNA-dye complex with an increase in fluorescence > 100-fold compared to the unstained cell, and 4)dyes can be used to quantify double-stranded DNA. The high sensitivity allowed the quantification of the DNA of the smallest known phyto-plankter (Prochlorococcus) as well as bacteria found in some of the algal cultures. Of the 12 taxonomic classes tested, only the 3 Nannochloropsis spp. (Eustagmatophyceae) stained poorly, and a few members of the Chlorophyceae and Pelagophyceae showed poor staining occasionally. In general, maximal fluorescence was achieved within 15 min after addition of the dye. Although the PicoGreen dye stained some living phytoplankton species, preservation is recommended for quantitation. SYTOX Green did not stain live cells. The combination of the dyes, therefore, allows the discrimination between live and dead cells in some algal groups (Prochlorococcus, diatoms, prasinophytes, and pelagophytes). Paraformaldehyde was preferred over glutaraldehyde for fixation to avoid (induced) green autofluorescence.
Article
Toxic dinoflagellate species that are not endemic to an area can be inadvertently introduced when their cysts are discharged with the ballast tank sediments of bulk container ships. These species, which can affect fish- and shellfish-farms, pose a serious threat to public health and aquaculture. Among 80 cargo vessels entering Australian ports, 40% contained viable dinoflagellate cysts and 6% carried the cysts of the toxic dinoflagellates Alexandrium catenella and A. tamarense (up to an estimated 300 million cysts per ship). The introduction of new Australian quarantine measures is discussed; however, the implications of this potential spreading of toxic algae are global.
Article
Ballast water was sampled on 12 occasions before and after an exchange process carried out in regional seas in order to assess the efficiency of this type of ballast water management at reducing the abundance and diversity of phytoplankton. Although there was an overall reduction in the average abundance and number of taxa after exchange this was not consistent between tanks and voyages. On some occasions there were changes in species composition after exchange and, in some cases, there were increases in potentially harmful species after the exchange process. Factors such as the depth of the water during the exchange process, the season and the method of exchange influenced the efficacy of the exchange process. The variability in the results after exchange mean that this is unlikely to be a ballast water management method that would give consistent results and careful consideration would have to be given to the suitability of using this method in regional seas as a means of reducing the risk of introducing non-native species.