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The pressure on scarce freshwater resources from intensifying human activity is rising across the globe. This study presents the case of Jatiluhur—Indonesia’s largest reservoir, where unregulated aquaculture expansion has contributed to environmental degradation and associated conflicts with other water-users. Aiming to identify a strategy to improve the sustainability of cage aquaculture within Jatiluhur reservoir and other freshwater bodies facing similar challenges, this study consisted of an initial analysis of time bound satellite images of the reservoir and a systematic survey of 112 aquaculture farms. The results revealed that, with more than 45 000 production units in 2020, more than half of which are placed outside government-approved aquaculture zones, the carrying capacity of the reservoir is exceeded. An analysis of the farm-level production practices, pertinent to environmental regulation, indicated the existence of three main production strategies, with significant differences in eutrophication potential among them that would lead to better articulated policy actions. A feed manufacturer-focused policy to reduce total phosphorus levels in formulated diets by more than half, but still within the optimal level for fish performance, would have the most impact. Enforcement of registration and removal of illegal production units supported by satellite-based monitoring of compliance are key recommendations to support intensive cage culture remaining an important economic activity.

Governance and management strategies for aquaculture development were examined for a select number of jurisdictions covering a range of marine aquaculture production to better understand the degree to which concepts of "Ecological Carrying Capacity" (ECC) are incorporated into management tools or permitting requirements for aquaculture development. Policies, regulations, and strategic plans were sought through professional knowledge and, at times, using web-based searches. Aquaculture ECC, defined here as, "the magnitude of aquaculture production that can be supported without leading to unacceptable changes in ecological process, species, populations, or communities in the environment," was not strictly applied in any jurisdiction's aquaculture policy documentation. A broadened search to consider the concept of aquaculture carrying capacity (CC) more generally was conducted. Of the ten nations examined, CC concepts could be found in policy documentation of several nations. The inclusion of CC concepts in policy and strategic planning can be used as part of a suite of management tools to promote sustainable aquaculture within FAO's Ecological Approach to Aquaculture. [ABSTRACT FROM AUTHOR]

Abstract: The visual impact of aquaculture is a controversial issue and in some countries must be assessed prior to any new development. However, at present, there are no definitive, objective methods used to evaluate the potential visual impacts of new aquatic farms and therefore assessment is difficult for both developers and regulators. This study presents a GIS based methodology for use in the visual assessment of a potential new coastal fish farm development, focusing on both sea cages and the associated land based structures. The methodology has been applied to a case study area, the Western Isles located off the North West coast of Scotland, which already has an extensive aquaculture industry and significant potential for future growth. Using a two stage sequential modelling process, the methodology combines visual, seascape and landscape analysis within a GIS environment to produce spatial models indicating where there is the potential for new aquaculture development with minimal visual impact. The preliminary visual assessment model combines a series of Boolean viewsheds with landscape and seascape sensitivity models to assess the potential visibility across different user groups and the sensitivity of the area to visual change. The second stage focuses on an area identified from the preliminary model as having potential for development and then performs a more detailed analysis using a site specific proportional visual impact model. This model quantifies the impact by assessing the proportion of viewpoints from which the proposed development can actually be seen. Both stages of the modelling process provide valuable information and support for decision makers regarding the potential visual impacts of aquaculture. [Copyright &y& Elsevier]

Abstract: Combining GIS with neuro-fuzzy modeling has the advantage that expert scientific knowledge in coastal aquaculture activities can be incorporated into a geospatial model to classify areas particularly vulnerable to pollutants. Data on the physical environment and its suitability for aquaculture in an Irish fjard, which is host to a number of different aquaculture activities, were derived from a three-dimensional hydrodynamic and GIS models. Subsequent incorporation into environmental vulnerability models, based on neuro-fuzzy techniques, highlighted localities particularly vulnerable to aquaculture development. The models produced an overall classification accuracy of 85.71%, with a Kappa coefficient of agreement of 81%, and were sensitive to different input parameters. A statistical comparison between vulnerability scores and nitrogen concentrations in sediment associated with salmon cages showed good correlation. Neuro-fuzzy techniques within GIS modeling classify vulnerability of coastal regions appropriately and have a role in policy decisions for aquaculture site selection. [Copyright &y& Elsevier]

Increasing research is highlighting the fact that streams provide crucial ecosystem services through the biogeochemical and ecological processes they sustain. Freshwater land-based salmonid farms commonly discharge their effluents into low order, headwater streams, partly due to the fact that adequate freshwater resources for production are commonly found in undisturbed areas. We review the effects of salmonid farm effluents on different biological components of stream ecosystems. Relevant considerations related to the temporal and spatial scales of effluent discharge and ecological effects are discussed. These highlight the need to characterize the patterns of stressor discharge when assessing environmental impacts and designing ecological effects studies. The potential role of multiple stressors in disrupting ecosystem structure and function is discussed with an emphasis on aquaculture veterinary medicines. Further research on the effects of veterinary medicines using relevant exposure scenarios would significantly contribute to our understanding of their impact in relation to other effluent stressors. [Copyright &y& Elsevier]

In earlier single-species toxicity tests we showed the negative effects on the calanoid copepod Acartia tonsa upon exposure to cypermethrin, a pesticide used in treatment for sea lice in salmon farming. In the present study we assessed effects at a higher level of biological organization and under a more realistic exposure scenario using mesocosms. The results showed that simulated field studies (SFSs) could be conducted with the mesocosms designed here. When cypermethrin was applied inside these mesocosms, its concentration decreased exponentially following a first-order kinetics model. The pesticide immediately reduced zooplankton density and biodiversity not only directly, by killing copepods, but also indirectly, by increasing the numbers of rotifers. Zooplankton density recovered after treatment, but zooplankton biodiversity remained altered. In an open environment, however, the rapid dissipation of the pesticide, coupled with population processes of compensation, migration, and immigration, may lead to recovery of the affected zooplankton communities. [Copyright &y& Elsevier]

In this study, we have developed an approach to classify the suitability of shallow coastal lagoons for pacific oyster aquaculture as the first step in a site selection process. Historical bio-physical data and local knowledge were combined to produce overall scores for biological and logistical criteria relevant for oyster farming which were then combined using Multi-Criteria Analysis (MCA) for an overall lagoon suitability score. A Dynamic Energy Budget growth model was also used to identify and rank suitability of shallow coastal lagoons to host Pacific oysters farming sites. Furthermore, modelled growth data were used to estimate the production cycle length and the potential productivity of the newly identified sites. The results indicated that biological and logistic factors were suitable for Pacific oyster farming in eleven out of twelve of the lagoons considered. However, acquiring water classification for shellfish farming and maintaining high water quality standards will be critical for any sustainable development of culture areas. Potential production figures and logistic scores, clearly indicates in which lagoons investments should be focused and what output could be realised from these very productive ecosystems. The results can be used to indicate where more detailed assessment should take place. As remote-sensing technologies continue to develop and algorithms for the interpretation of ocean colour in coastal areas keep improving, this multidisciplinary approach will increase our ability to estimate aquaculture production in complex aquatic systems. This approach will provide stakeholders, policy makers and regulators with a new and powerful decision-making tool for site selection of sustainable oyster farming activities and the management of the surrounding coastal areas. Image 1 • Classification of coastal lagoons suitability for Pacific oyster farming site selection. • Multidisciplinary approach combining biological, logistical and geographical data. • Prioritisation of investments for sustainable coastal zone management. [ABSTRACT FROM AUTHOR]

Salmon farming has developed significantly since its inception in Scotland. It is now an established part of the rural communities in which it operates, is a key contributor to the Scottish and UK economies and has an important role in meeting the growing global demand for food. However, the Scottish salmon industry is subject to a number of regulatory, environmental and social licence challenges, amongst others, that must be overcome if it is to continue to develop and expand to meet ambitious targets for increasing production. Beyond compliance is one way in which the industry can seek to overcome such challenges. Based on qualitative data gathered from analysis of industry reports, stakeholder interviews and questionnaires, this paper i) provides an overview of challenges currently facing Scottish salmon farming, ii) presents beyond compliance measures already taking place, iii) discusses industry opportunities and challenges in terms of beyond compliance, and iv) offers suggestions for the future of beyond compliance, including incentives and ways in which it could be effectively measured. • Beyond compliance is anything a company does additional to statutory regulatory requirements. • A multi-strategy study to explore beyond compliance for Scottish salmon aquaculture. • Beyond compliance at the farm level focuses on environmental quality standards. • Broader issues such as over-use of resources are also addressed but not currently regulated. • Lessons from other industries include ways to collaborate and measure beyond compliance. [ABSTRACT FROM AUTHOR]

This study explores the critical factors of pond aquaculture development in Nigeria, and opportunities and challenges for sustainable expansion of the sector. Aquaculture’s role in food security especially in developing countries has been recognized, including its growth potential. However, Nigeria’s aquaculture development remains slow. Using Delphi technique, key factors influencing aquaculture were identified: availability/cost of aquafeed, land use change, government policy and climate change. Then scenario planning was used to develop four alternative but plausible pathways (scenarios) for Nigerian aquaculture development to 2035, depicting baseline, favourable, somewhat favourable, and unfavourable situations. For each scenario, future pond aquaculture production was estimated by modelling future changes in land use and pond yield potential. Government estimates suggest a potential of producing 2.5 million metric tonnes (t) of fish annually, but our results suggest Nigeria is unlikely to reach this estimate by 2035 without interventions. While the qualitative scenarios are useful to enhance discussions on potential interventions for improving aquaculture production and sustainability, the quantitative projections can be used for evaluating these interventions.

Introduction: China is responsible for more than 60% of global aquaculture production. As the frontiers of food production have expanded, the cultivation of marine organisms in coastal zones and the open ocean has grown rapidly. The dominant mariculture industry in China is suspended mariculture, which uses net cages, ropes, or other structures suspended in the water column to cultivate aquatic organisms. This systematic, quantitative review provides a clear and comprehensive account of research that has investigated the adverse impacts of suspended mariculture in China and reviews research that has applied Integrated Multi-Trophic Aquaculture (IMTA) systems for mitigating impacts. This work builds on 218 peer reviewed papers that have been published in English-language journals. Outcomes: Eighteen impacts were identified, including chemical, ecological, physical, and socioeconomic impacts. Eighteen measures for improving suspended mariculture were recommended consisting of government department, farm management, and ecological engineering measures. IMTA was the most frequently recommended measure. The capabilities of IMTA for bioremediation and increased farm production were the most frequently studied advantages. Seven other benefits have been explored but remain understudied. The current challenges facing the expansion of commercial IMTA include limited use of new technology, limited skills development, decreasing production of low trophic-level species, biogeographic and temporal barriers, and negative system feedbacks. Conclusion: Despite challenges, implementing commercial IMTA is a promising measure for reducing the impacts of suspended mariculture because it presents a range of secondary benefits that can improve the overall sustainability of aquaculture in the coastal zone.