Great egret (Ardea alba) habitat selection and foraging behavior in a temperate estuary: Comparing natural wetlands to areas with shellfish aquaculture

Movement by animals to obtain resources and avoid predation often depends on natural cycles, and human alteration of the landscape may disrupt or enhance the utility of different habitats or resources to animals through the phases of these cycles. We studied habitat selection by GPS/accelerometer-tagged great egrets (Ardea alba) foraging in areas with shellfish aquaculture infrastructure and adjacent natural wetlands, while accounting for tide-based changes in water depth. We used integrated step selection analysis to test the prediction that egrets would express stronger selection for natural wetlands (eelgrass, tidal marsh, and other tidal wetlands) than for shellfish aquaculture areas. We also evaluated differences in foraging behavior among shellfish aquaculture areas and natural wetlands by comparing speed travelled (estimated from distance between GPS locations) and energy expended (Overall Dynamic Body Acceleration) while foraging. We found evidence for stronger overall habitat selection for eelgrass than for shellfish aquaculture areas, with results conditional on water depth: egrets used shellfish aquaculture areas, but only within a much narrower range of water depths than they used eelgrass and other natural wetlands. We found only slight differences in our metrics of foraging behavior among shellfish aquaculture areas and natural wetlands. Our results suggest that although great egrets appear to perceive or experience shellfish aquaculture areas as suitable foraging habitat during some conditions, those areas provide less foraging opportunity throughout tidal cycles than natural wetlands. Thus, expanding the footprint of shellfish aquaculture into additional intertidal areas may reduce foraging opportunities for great egrets across the range of tidal cycles. Over longer time scales, the ways in which natural wetlands and shellfish aquaculture areas adapt to rising sea levels (either through passive processes or active management) may change the ratios of these wetland types and consequently change the overall value of Tomales Bay to foraging great egrets.

Participatory Qualitative Modeling to Assess the Sustainability of a Coastal Socio-Ecological System

Assessing the sustainability of socio-ecological systems requires understanding the interactions between numerous ecological, economic and social components. Models are often used to investigate how interactions shape system feedbacks and drive the complex dynamics at play in such systems. However, building these models is a non-trivial exercise, which often neglects stakeholder knowledge and perceptions. We adopted a participatory approach that relies on conducting workshops to engage stakeholders into the development of qualitative models of system feedback. This type of participatory qualitative modeling is well suited to address the complexity of socio-ecological systems in a holistic manner, identify key stakes and feedbacks, and predict responses to perturbations. We use this approach to investigate the factors that condition sustainability of the socio-ecological system associated with shellfish aquaculture in the Normand-Breton Gulf in France. Six region-specific workshops were organized with shellfish producers, managers and other stakeholders to identify and describe key components, interactions and pressures that contribute to overall socio-ecological dynamics. Differences and commonalities in system perceptions were identified across the different regions and focus groups. We reconciled stakeholder-specific discrepancies in model structure into a synthetic representation that conciliates alternative views of the system. Next, we predicted how the system might respond to alternative scenarios of change. Overall, our participatory qualitative modeling exercise identified key drivers of the system under study that constitute effective management levers to maintain system sustainability. For instance, low social acceptability of the aquaculture industry generally appears to be a major constraint on the sustainability of shellfish aquaculture in the Normand-Breton Gulf, while reducing rearing density appears to be a key driver of sustainability.

MANAJEMEN PENINGKATAN EKONOMI MASYARAKAT MELALUI BUDIDAYA KERANG HIJAU DALAM PRESPEKTIF MAQOSID SYARIAH

The economic management of the majority Campurejo village society relies on shellfish aquaculture. They implement shellfish rearing business practice by installing bamboo into the sea in order to catch the shell easier. Shellfish aquaculture is considered as a very promising occupation because it is highly profitable. Campurejo people formerly are categorized as a lower-middle economic society.Phenomenological approach is used as the research method in this study. Moreover, this research uses empirical data with primary data taken from in-depth interviews with several parties which are involved in green shellfish aquaculture activities and the secondary data obtained from many references related to maqashid syariah and others. The data collection techniques using interviews, observation and documentation. In the data analysis aspect, it is through the stages of data reduction, data presentation, verification and conclusion. The author then uses a data triangulation method in order to test the validity of the data.The results shows good economic management in green shellfish aquaculture will lead to profit which has increased the community's economy and at the same time has a chain effect on the economy in terms of education, health, religiosity and child upbringing. The benefits of shellfish aquaculture aside from providing special impacts, also provide general impacts by opening up jobs and helping the underprivileged people. The variety benefits of green shellfish aquaculture has relevance to the spirit of the sharia which intends to prosper the community. Looking at the aquaculture process and the results associated with the implementation of maqasid syariah through the media of maslahah mursalah, it has been in accordance with the implementation requirements. Along these lines, green shellfish aquaculture is a business practice that is actually accommodated in the unwritten scope of sharia.

Current Status of Forecasting Toxic Harmful Algae for the North-East Atlantic Shellfish Aquaculture Industry

Across the European Atlantic Arc (Scotland, Ireland, England, France, Spain, and Portugal) the shellfish aquaculture industry is dominated by the production of mussels, followed by oysters and clams. A range of spatially and temporally variable harmful algal bloom species (HABs) impact the industry through their production of biotoxins that accumulate and concentrate in shellfish flesh, which negatively impact the health of consumers through consumption. Regulatory monitoring of harmful cells in the water column and toxin concentrations within shellfish flesh are currently the main means of warning of elevated toxin events in bivalves, with harvesting being suspended when toxicity is elevated above EU regulatory limits. However, while such an approach is generally successful in safeguarding human health, it does not provide the early warning that is needed to support business planning and harvesting by the aquaculture industry. To address this issue, a proliferation of web portals have been developed to make monitoring data widely accessible. These systems are now transitioning from “nowcasts” to operational Early Warning Systems (EWS) to better mitigate against HAB-generated harmful effects. To achieve this, EWS are incorporating a range of environmental data parameters and developing varied forecasting approaches. For example, EWS are increasingly utilizing satellite data and the results of oceanographic modeling to identify and predict the behavior of HABs. Modeling demonstrates that some HABs can be advected significant distances before impacting aquaculture sites. Traffic light indices are being developed to provide users with an easily interpreted assessment of HAB and biotoxin risk, and expert interpretation of these multiple data streams is being used to assess risk into the future. Proof-of-concept EWS are being developed to combine model information with in situ data, in some cases using machine learning-based approaches. This article: (1) reviews HAB and biotoxin issues relevant to shellfish aquaculture in the European Atlantic Arc (Scotland, Ireland, England, France, Spain, and Portugal; (2) evaluates the current status of HAB events and EWS in the region; and (3) evaluates the potential of further improving these EWS though multi-disciplinary approaches combining heterogeneous sources of information.

The Contributions of Shellfish Aquaculture to Global Food Security: Assessing Its Characteristics From a Future Food Perspective

The United Nation’s 2030 development agenda adopted in 2015 outlines 17 Sustainable Development Goals (SDGs), and the organization has continued to put food security in the center of its vocalization. Aquaculture is currently the fastest-growing food production sector globally and a sustainable option for attaining food security. Food as a basic necessity for man’s survival is always a timely issue. Hence, owing to aquaculture’s unique role, it is expected that the demand for aquatic products (especially seafood) will continue to increase due to geometric population growth. Many seafood products are among the critical protein sources in the world. This is partly because they have micronutrients and essential fatty acids that are not present in land-based protein sources. According to the Food and Agriculture Organization, shellfish is one of the main cultured aquaculture groups in the world. Hence, the development of shellfish aquaculture has an important role in sustainable food supply and food security. In this article, an overview of the current and projected contributions of shellfish aquaculture to global food security is presented. Apparently, shellfish aquaculture in the next few decades will have to be intensified to bridge the gap between demand and supply in a cost-effective manner. Also, food waste would have to be reduced and natural resources should be used more efficiently to minimize the negative impacts on aquaculture on the environment.