Dams are known to trap pollutants such as metals and PCBs in the sediment that accumulates within their reservoirs. As more attention is paid to microplastics, an emerging contaminant in waterways worldwide, and how they move along rivers, whether microplastic particles also accumulate behind dams is an important question for informing estimates of global river inputs to oceans. In this study, we measured microplastic concentrations above, below, and within the reservoirs of six dams near Ithaca, NY USA. Samples were processed following the wet peroxide oxidation method and visual counting, followed by Raman Spectroscopy validation. We found that microplastic concentrations in sediment within reservoirs was significantly higher than in sediment above the dams (p = 0.005), and in water samples, concentrations within reservoirs was significantly lower (p = 0.02). Plastic fibers were the dominant plastic type, but in within-reservoir sediment samples, less abundant plastic types such as plastic fragments were found in higher proportions. These results show that the sediment collecting behind dams is one sink for microplastics in river systems at long timescales, indicating that accounting for dams may be important when modeling global riverine microplastic transport.
Plastic pollution is a pervasive problem to marine life. This study aimed (1) to investigate levels of microplastic in wild and farmed mussels (Perna perna), and (2) to assess the effectiveness of depuration in reducing microplastics. Wild and farmed mussels were sampled from Guanabara Bay (Southwestern Atlantic). Four treatments were compared (N = 10 mussels/treatment): wild non-depurated mussels, wild depurated mussels, farmed non-depurated mussels, and farmed depurated mussels. Up to 31.2 ± 17.8 microplastics/mussel (≥0.45 μm) were detected (means ± SD), and microplastics were present in all 40 individuals analyzed. Nylon fibers were more abundant than polymethyl methacrylate (PMMA) fragments. Blue, transparent, and red nylon fibers were more abundant in both wild and farmed mussels. Although 93 h-depuration significantly reduced microplastics (ANOVA, p = 0.02) in both wild (46.79%) and farmed mussels (28.95%), differences between farmed and wild mussels were not significant (p > 0.05). Depuration was more effective in removing blue fibers. Our results highlight the importance of depuration in reducing microplastic pollution in seafood.
This paper provides a quantitative assessment of students' attitude and behaviors towards marine litter before and after their participation to SEACleaner, an educational and citizen science project devoted to monitor macro- and micro-litter in an Area belonging to “Pelagos Sanctuary” (Mediterranean Sea). This approach produced interesting outcomes both for the research sector of marine pollution and environmental monitoring, as well for the scientific and environmental education. Here we focus on citizen science as an effective vector for raising young people awareness of marine litter and fostering sound behaviors. A specially designed questionnaire was administered to 87 High School students, to test the validity of such approach. The results state that the students change quantitatively their perception of beach-litter causes and derived problems, and they improved their knowledge about the main marine litter sources and the role of the sea in the waste transport and deposition along the coast.
This article examines the various requirements for the exercise by a State of its enforcement jurisdiction to investigate instances of fisheries crime and its adjudicative jurisdiction to try fisheries crime cases. In the process, the jurisdictional bases available are identified, the extent of the powers available are determined and concrete examples provided. It concludes that the international law rules governing State jurisdiction over fisheries crime at sea do not place any insurmountable obstacle to the criminalisation, investigation and adjudication of acts of transnational organised fisheries crime. What is needed is a more positive attitude towards the complexities of State ocean jurisdiction and the existing scope of the States’ duties towards the marine environment, and the marine living resources more specifically.
The concept of sustainable fishing is well ingrained in marine conservation and marine governance. However, I argue that the concept is deeply flawed; ecologically, socially and economically. Sustainability is strongly related, both historically and currently, to maximum long-term economic exploitation of a system. Counter-intuitively, in fisheries, achieving this economic exploitation often relies on government subsidies. While many fish populations are not sustainably fished biologically, even ‘sustainably harvesting’ fish results in major ecological changes to marine systems. These changes create unknown damage to ecosystem processes, including carbon capture potential of the ocean. The spatial scale of commercial fishing processes can also lead to social and food security issues in local, coastal communities that rely on fish for dietary needs. A radical alternative proposal is provided to the current situation. Ultimately, offshore fishing should be stopped completely and fish catches should rely instead on inshore fisheries. While such an approach may require a change in thinking and human behaviour regarding fish, I demonstrate that there are many benefits of this approach, including ecological, social and to local coastal economies, and few negatives, although management measures and coastal marine protected areas to protect vulnerable species and habitats would still be required. As such, the approach suggested is much more akin to a holistic definition of sustainability or ‘prevention of ecological harm’, rather than the maximum long-term exploitation of an ecosystem which is an underlying assumption of much fisheries and conservation research. While the suggestions in the study would benefit from further ecological, social and economic modelling, any movement towards restricting offshore catches should provide some degree of the benefits detailed.
An online atlas of the Coral Triangle region of the Indo-Pacific biogeographic realm was developed. This online atlas consists of the three interlinked parts: (1) Biodiversity Features; (2) Areas of Importance for Biodiversity Conservation; (3) recommended priorities for Marine Protected Area (MPA) Network Expansion (http://www.marine.auckland.ac.nz/CTMAPS). The first map, Biodiversity Features, provides comprehensive data on the region's marine protected areas and biodiversity features, threats, and environmental characteristics. The second provides spatial information on areas of high biodiversity conservation values, while the third map shows priority areas for expanding the current Coral Triangle MPA network. This atlas provides the most comprehensive biodiversity datasets that have been assembled for the region. The datasets were retrieved and generated systematically from various open-access sources. To engage a wider audience and to raise participation in biodiversity conservation, the maps were designed as an interactive and online atlas. This atlas presents representative information to promote a better understanding of the key marine and coastal biodiversity characteristics of the region and enables the application of marine biodiversity informatics to support marine ecosystem-based management in the Coral Triangle region.
Ensuring productive and sustainable fisheries involves understanding the complex interactions between biology, environment, politics, management and governance. Fisheries are faced with a range of challenges, and without robust and careful management in place, levels of anthropogenic disturbance on ecosystems and fisheries are likely to have a continuous negative impact on biodiversity and fish stocks worldwide. Fisheries management agencies, therefore, need to be both efficient and effective in working towards long-term sustainable ecosystems and fisheries, while also being resilient to political and socioeconomic pressures. Marine governance, i.e., the processes of developing and implementing decisions over fisheries, often has to account for socioeconomic issues (such as unemployment and business developments) when they attract political attention and resources. This paper addresses the challenges of (1) identifying the main issues in attempting to ensure the sustainability of fisheries, and (2) how to bridge the gap between scientific knowledge and governance of marine systems. Utilising data gained from a survey of marine experts from 34 nations, we found that the main challenges perceived by fisheries experts were overfishing, habitat destruction, climate change and a lack of political will. Measures suggested to address these challenges did not demand any radical change, but included extant approaches, including ecosystem-based fisheries management with particular attention to closures, gear restrictions, use of individual transferable quotas (ITQs) and improved compliance, monitoring and control.
Marine resource management is shifting from optimizing single species yield to redefining sustainable fisheries within the context of managing ocean use and ecosystem health. In this introductory article to the theme set, “Plugging spatial ecology into ecosystem-based management (EBM)” we conduct an informal horizon scan with leaders in EBM research to identify three rapidly evolving areas that will be game changers in integrating spatial ecology into EBM. These are: (1) new data streams from fishers, genomics, and technological advances in remote sensing and bio-logging; (2) increased analytical power through “Big Data” and artificial intelligence; and (3) better integration of social dimensions into management. We address each of these areas by first imagining capacity in 20 years from now, and then highlighting emerging efforts to get us there, drawing on articles in this theme set, other scientific literature, and presentations/discussions from the symposium on “Linkages between spatial ecology and sustainable fisheries” held at the ICES Annual Science Conference in September 2017.
Climate change and sea level rise (SLR) poses serious risks to coastal communities around the world requiring nations to apply adaptation laws and policies. Climate change will exacerbate the existing threats to vulnerable communities, such as the poor, and threaten the food security of populations in coastal areas through the effects of flooding due to coastal inundation. Indonesia is an Archipelagic State of over 17,000 islands and is vulnerable to climate change impacts in its coastal areas and especially in its highly populated low lying delta areas, such as Jakarta and Semarang, where vulnerability to sea level rise is evident. The adequacy of the legal adaptation framework in Indonesia to respond to this climate vulnerability is assessed and it is found to have limited consideration of the community burden arising from these climate and SLR uncertainties. A more inclusive social justice approach could assist government to respond to the impacts from these issues and to their implications for vulnerable groups. The nation can improve adaptive legal measures to address climate change impacts and increase the involvement of local people in climate change adaptation decision making. Funding is required to assist policy makers to further incorporate adaptation into decision making, and this could improve social justice outcomes for vulnerable Indonesian coastal communities.
Over the last decade there has been a global effort to eco-engineer urban artificial shorelines with the aim of increasing their biodiversity and extending their conservation value. One of the most common and viable eco-engineering approaches on seawalls is to use enhancement features that increase habitat structural complexity, including concrete tiles molded with complex designs and precast “flowerpots” that create artificial rock pools. Increases in species diversity in pits and pools due to microhabitat conditions (water retention, shade, protection from waves, and/or biotic refugia) are often reported, but these results can be confounded by differences in the surface area sampled. In this study, we fabricated three tile types (n = 10): covered tile (grooved tile with a cover to retain water), uncovered tile (same grooved tile but without a cover) and granite control. We tested the effects of these tile types on species richness (S), total individual abundance (N), and community composition. All tiles were installed at 0.5 m above chart datum along seawalls surrounding two island sites (Pulau Hantu and Kusu Island) south of Singapore mainland. The colonizing assemblages were sampled after 8 months. Consistent with previous studies, mean S was significantly greater on covered tiles compared to the uncovered and granite tiles. While it is implied in much of the eco-engineering literature that this pattern results from greater niche availability allotted by microhabitat conditions, we further investigated whether there was an underlying species-individual relationship to determine whether increases in S could have simply resulted from covered tiles supporting greater N (i.e., increasing the probability of detecting more species despite a constant area). The species-individual relationship was positive, suggesting that multiple mechanisms are at play, and that biodiversity enhancements may in some instances operate simply by increasing the abundance of individuals, even when microhabitat availability is unchanged. This finding underscores the importance of testing mechanisms in eco-engineering studies and highlights ongoing mechanistic uncertainties that should be addressed to inform the design of more biodiverse seawalls and urban marine environments.