Coastal environments of the world have been exposed to eutrophication for several decades. Recently the quality of coastal waters has been gradually and successfully improved, however the improvement has caused another issue in ecoastal ecosystem services, called oligotrophication. Local stakefolders have suggested that oligotrophication reduces pelagic productivity and moreover fishery production in coastal ecosystems, while oligotrophication with high transparency has recovered benthic macrophyte vegetation which have been depressed by phytoplankton derived from eutrophication. In particular, seagrass species is one of the most important coastal vegetation for climate change mitigation and adaptation, which has been welcomed by another stakefolders. Therefore, harmonizing coastal fishery with environmental conservation is now essential for the sustainable use of ecosystem services. Here, we just started some practice in field based on the interdisciplinary approach including ecological actions, socio-economical actions and moreover psychological actions to find the integrative coastal management maximizing well-beings of various stakefolders, which is essential to harmonize environmental conservation with sustainable fishery and aquaculture. Now we are focusing on the interaction between oyster aquaculture and seagrass vegetation as an ecological action.
Aquaculture, Seafood, and Food Security
The debate over Brexit and the fisheries question has focused very largely on the expected benefits for the UK's fishing industry to the virtual exclusion of potential implications for the seafood supply chain. This paper refocuses attention on a supply chain now heavily dependent on both imports and exports of fish and fish products mainly to EU markets. Brexit could pose potentially significant problems arising from the imposition of tariff and non-tariff restrictions on trade and limitation on future movements of semi-skilled and unskilled EU migrants into the UK labour market. Three elements of the supply chain are likely to be directly affected: the shellfish and small scale fisheries sectors impacted by tariff and non-tariff restrictions and perhaps most significantly the fish processing industry, similarly affected by trade restrictions and heavily dependent on EU labour. Brexit has also been the catalyst for renewed pressures in Scotland for further devolution of powers relating to the fishing industry that at some future date could see the development of two distinctive seafood supply chains within the UK.
Shellfish profession is jeopardized by water quality problem that concerns inlet, with the need to protect the animals from pathogens contaminations, and effluents potentially harmful for the environment with the presence of pathogens, nutrients or organic matter. In this study, ultrafiltration was tested to answer these issues. The objective of the work was two-fold: (i) treat a real effluent from an oyster breeding, the pilot had to continuously face a water containing organic matter and pathogens and (ii) use ultrafiltered water to feed an oyster spat. The process was proved to be efficient in terms of total suspended solids (TSS) and bacterial retention, and especially for Vibrio bacteria, some of whom are potentially harmful for shells. The sustainability of the process facing this pollution was demonstrated and thus for different filtration conditions. Indeed, backwashes and air-backwashes performed were efficient enough to control the fouling generated, so a chemical cleaning was necessary about every 12 h. Water quality parameters, physico-chemical and bacterial, of ultrafiltered effluents were similar to the one obtained with a classical seawater used to feed oyster spats. Ultrafiltration was efficient to treat an effluent from oyster farm and produce water allowing the grown of juveniles. This process could be a solution to reuse effluents in shellfish farms.
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.
Sustainability standards for seafood mainly address environmental performance criteria and are less concerned with the welfare of fisheries workers who produce the seafood. Yet human rights violations such as slavery and human trafficking are widespread in fisheries around the world, and underscore the need for certification bodies and other seafood supply chain actors to improve social performance, in addition to addressing environmental challenges. Calls for socially responsible seafood have referenced human rights law and policy frameworks to shape the guiding principles of socially responsible seafood and to provide the legal machinery to implement these aspirations, but practical guidance on how to achieve this is lacking. To provide clarity on this challenge, we reviewed the literature concerning human rights in the seafood supply chain, and prepared an analysis of opportunities and challenges to implement socially responsible seafood through relevant human rights, legal and policy instruments. We observe that human rights laws are generally framed in favour of addressing violations of civil and political rights, but there remains considerable scope for applying economic, social and cultural (ESC) rights in this context. Other challenges include weakly defined ESC rights infringements, a lack of straightforward mechanisms to enforce human rights entitlements, and practical difficulties such as resources to support and secure rights. On the positive side, governments can draw on international instruments to inspire national policies and legislation to eliminate illegalities from the seafood supply chain. However, for socially responsible seafood principles to translate into tangible actions, these objectives must be rooted in clear legal obligations and be supported by sufficient national capacity and political will.
Juvenile scallops of Pecten maximus were studied to see the capability to clear out and incorporate salmon feed and feces (30 μg L-1). Algae were also given, in a low and high concentration in addition to feed and feces, to mimic a winter and summer situation in Norwegian waters. Rhodomonas baltica and Chaetoseris muelleri were provided in a concentration of 50 μg L-1 and 300 μg L-1. The feeding trial lasted for 27 days. Clearance rate was measured to study filtration characteristics, while fatty acid profiling and stable isotopes of nitrogen and carbon were used to trace the uptake of salmon feed and feces in the digestive gland and muscle of juvenile scallops (30–35 mm shell height). The results show that the scallops could clear out and retain both salmon feed and feces particles, although at a statistically lower clearance rate than the algae. Fatty acid profiling revealed that the scallops assimilated and incorporated the consumed salmon feed and feces, given with either high or low algae concentrations, in their tissues, where the fatty acid C18:1n9 was used as a tracer fatty acid. The digestive gland of the scallops that were fed salmon feed and feces contained a higher share of C18:1n9 than those that were only fed algae. The digestive gland reflected the fatty acid composition of the diet, while the fatty acid composition of the muscle, which also changed, reflected a more complex relation between diet and metabolic processes in the tissue. The use of stable isotopes of carbon and nitrogen to trace food sources was inconclusive in this study due to low differences between samples fed different feeds. Fatty acid profiling was a more sensitive method for tracing low concentrations of salmon feed and feces in the algae diet of scallops. Our results suggest that P. maximus could be a candidate for integrated multitrophic aquaculture (IMTA) and that scallops have the potential to utilize small particles of wasted salmon feed and feces during a winter situation with low phytoplankton concentration and during an algal bloom in Norwegian waters.
The recent Marine Stewardship Council certification for the Russian Barents Red King Crab demonstrates the consequences of overlooking ecological factors in seafood sustainability assessments. The crab is commercially valuable but has uncertain invasive effects for the ecosystem. Russian authorities manage it as a long-term fishery and openly accept the co-incidental risks that come along with the invasion. The Russian crab fishery is monopolized and there is limited transparency on both quota acquisition and decision-making regarding its management. Including ecological and socio-political dimensions expands the sustainability definition to more closely match general consumer perceptions of what certified sustainability represents. The focus of widely trusted certification processes on fishery practices masks important sustainability considerations from end consumers and may distort their choices.
Offshore mariculture could enable increased seafood production and economic development while alleviating pressure on coastal ecosystems and wild fisheries. In the Caribbean, however, an integrated assessment of the ecological and economic potential for mariculture in the region is lacking. We assess site suitability and develop a spatial bioeconomic model to predict yields and profits for offshore cobia (Rachycentron canadum) mariculture across 30 jurisdictions in the Caribbean. We find that (1) approximately 1.4% of the study area may be technically feasible; (2) the model could avoid conflicts with other uses and sensitive habitats and protected areas; and (3) the model could be economically profitable, with the potential to produce almost half the amount of seafood that is currently harvested from wild fisheries globally. Here, we show that potential farm-scale production and profitability vary across and within countries and that accounting for the foreign investment risk associated with a country will impact estimated farm profitability.
Recent years have witnessed growing interest in applying ecosystem service (ES) frameworks to promote holistic decision-making and develop sustainable aquaculture. The goal of this review was to analyze the status quo of research on aquaculture ES and identify knowledge gaps and research priorities to better align ES with holistic decision-making. This study conducted a systematic review of the academic literature and analyzed the coverage of aquaculture ES across 94 publications. The research field has evolved substantially in the last ten years, reaching a multidisciplinary audience around the world. While research coverage included all major production environments (coastal marine, brackishwater, and freshwater) and cultured species groups (finfish, bivalves, crustaceans, and seaweeds), emphasis is currently limited towards certain types of aquaculture and study areas (namely, brackishwater shrimp farming). This review found a flexible but inconsistent application of ES concepts and methods to support multiple decision-contexts including policy, development, and conservation. This paper proposes a research agenda to address research gaps, adopt more holistic ES-driven research, and apply consistent and comparable ES measures through an aquaculture lens. Ultimately, this should be supported by a shift in thinking that frames aquaculture as ‘aqua-ecosystems’, recognizing aquaculture as fundamentally embedded within linked social and ecological systems.
Ocean acidification (OA) is one of the largest emerging and significant environmental threats for the aquaculture industry, jeopardizing its role as an alternative for supporting food security. Moreover, market conditions, characterized by price volatility and low value-added products, could exacerbate the industry's vulnerability to OA. We use a literature review on the biological consequences of OA over marine commercial species attributes to inform the empirical assessment of consumers' preferences for those attributes affected by OA, and consumers' responses to a set of market adaptation strategies suggested by the industry. We found that OA will have a negative impact on consumers' welfare due to the effects on commercial attributes of mussels aquaculture products. However, the main concerns for the industry are the market conditions. Thus, the industry's current adaptation strategies are focused on increasing their market share by offering new product assortments (with more value-added), regardless of the effect of OA on consumers' welfare. Despite this fact, the industry's strategies could eventually contribute to cope with OA since some specific segments of the market are willing to pay for new product assortments. This new market composition highlights the role of public institutions' reputation in issues related to food safety.