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

Abstract

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.

RETRACTED: Advantage of Species Diversification to Facilitate Sustainable Development of Aquaculture Sector

“…However, an often-encountered criticism of marine finfish net-pen aquaculture is that the uneaten feed and wastes pollute the bottom layer in aquaculture system typically under the pens [105], releasing nutrients that contribute to outbursts of algal bloom formation. Poorly managed intensive finfish and crustacean systems can contribute to the emergence of harmful pathogens and algal blooms, and sea urchins, shellfish, and sea cucumbers are very sensitive to toxic microalgae [106]. Thus, integrated species should be more than just biofilters; there is a need to consider organisms that convert soluble and solid nutrient discharges from the fed species and waste feed, together turning into sizable production with commercial value that is acceptable to consumers.…”

Combining Imaging Flow Cytometry and Molecular Biological Methods to Reveal Presence of Potentially Toxic Algae at the Ural River in Kazakhstan

“…The incidence and intensity of harmful algal blooms (HABs) as well as the associated economic impact have increased worldwide with warming water temperatures in recent years (Paerl and Paul, 2012;Jeppesen et al, 2017;Griffith and Gobler, 2020;Wells et al, 2020;Fernandes-Salvador et al, 2021). HABs are complex events typically caused by multiple factors occurring simultaneously, may threaten ecosystems, and lead to the degradation of water quality for recreation, drinking, and aquaculture (Heisler et al, 2008;Oliver et al, 2012;Jeppesen et al, 2017) with further changes in temperature, nutrient load, and oxygenation of aquatic environments.…”

Assessing the Performance and Application of Operational Lagrangian Transport HAB Forecasting Systems

“…However, given the uncertainties of the drift, either presentation is improved by an accompanying interpretation. These forecasts are not usually presented in isolation; they more often form part of HAB bulletins or HAB report web sites, such as those produced in ASIMUTH (Cusack et al 2016;Maguire et al 2016;Ruiz-Villarreal et al 2016;Silva et al 2016) and PRIMROSE projects (Davidson et al 2021;Fernandes-Salvador et al 2021), this issue. HAB early warning system presentations add in local measurements, general oceanographic conditions and expert advice, along with advective forecasts, which help to mitigate the problems of interpretation and user uptake identified above.…”