Food-Web and Ecosystem Structure of the Open-Ocean and Deep-Sea Environments of the Azores, NE Atlantic

The Marine Strategy Framework Directive intends to adopt ecosystem-based management for resources, biodiversity and habitats that puts emphasis on maintaining the health of the ecosystem alongside appropriate human use of the marine environment, for the benefit of current and future generations. Within the overall framework of ecosystem-based management, ecosystem models are tools to evaluate and gain insights in ecosystem properties. The low data availability and complexity of modeling deep-water ecosystems has limited the application of ecosystem models to few deep-water ecosystems. Here, we aim to develop an ecosystem model for the deep-sea and open ocean in the Azores exclusive economic zone with the overarching objective of characterizing the food-web and structure of the ecosystem. An ecosystem model with 45 functional groups, including a detritus group, two primary producer groups, eight invertebrate groups, 29 fish groups, three marine mammal groups, a turtle and a seabird group was built. Overall data quality measured by the pedigree index was estimated to be higher than the mean value of all published models. Therefore, the model was built with source data of an overall reasonable quality, especially considering the normally low data availability for deep-sea ecosystems. The total biomass (excluding detritus) of the modeled ecosystem for the whole area was calculated as 24.7 t km-2. The mean trophic level for the total marine catch of the Azores was estimated to be 3.95, similar to the trophic level of the bathypelagic and medium-size pelagic fish. Trophic levels for the different functional groups were estimated to be similar to those obtained with stable isotopes and stomach contents analyses, with some exceptions on both ends of the trophic spectra. Omnivory indices were in general low, indicating prey speciation for the majority of the groups. Cephalopods, pelagic sharks and toothed whales were identified as groups with key ecological roles in the ecosystem. Due to concerns on the use of ecosystem models with low confidence in exploring management decisions and ecological theories, the current version of this model should only be use with caution until biomass estimates are validated with survey data or the model is fitted to time series

Food-web and ecosystem structure of the open-ocean and deep-sea environments of the Azores, NE Atlantic

The Marine Strategy Framework Directive intends to adopt ecosystem-based management for resources, biodiversity and habitats that puts emphasis on maintaining the health of the ecosystem alongside appropriate human use of the marine environment, for the benefit of current and future generations. Within the overall framework of ecosystem-based management, ecosystem models are tools to evaluate and gain insights in ecosystem properties. The low data availability and complexity of modelling deep-water ecosystems has limited the application of ecosystem models to few deep-water ecosystems. Here, we aim to develop an ecosystem model for the deep-sea and open ocean in the Azores exclusive economic zone with the overarching objective of characterising the food-web and ecosystem structure of the ecosystem. An ecosystem model with 45 functional groups, including a detritus group, two primary producer groups, eight invertebrate groups, 29 fish groups, three marine mammal groups, a turtle and a seabird group was built. Overall data quality measured by the pedigree index was estimated to be higher than the mean value of all published models. Therefore, the model was built with source data of an overall reasonable quality, especially considering the normally low data availability for deep-sea ecosystems. The total biomass (excluding detritus) of the modelled ecosystem for the whole area was calculated as 24.7 t km-². The mean trophic level for the total marine catch of the Azores was estimated to be 3.95, similar to the trophic level of the bathypelagic and medium-size pelagic fish. Trophic levels for the different functional groups were estimated to be similar to those obtained with stable isotopes and stomach contents analyses, with some exceptions on both ends of the trophic spectra. Omnivory indices were in general low, indicating prey speciation for the majority of the groups. Cephalopods, pelagic sharks and toothed whales were identified as groups with key ecological roles in the ecosystem. Due to concerns on the use of ecosystem models with low confidence in exploring management decisions and ecological theories, the current version of this model should only be use with caution until biomass estimates are validated with survey data or the model is fitted to tim

H2020 UNITED : is scour protection suitable for flat oyster restoration in Belgium?

Once a key habitat in the North Sea, European flat oyster (Ostrea edulis) reefs have completely disappeared in the Belgium part of the North Sea (BPNS) due to a combination of factors, including overexploitation, destruction by bottom trawling and diseases such as bonamiosis. Across Europe, a number of projects and initiatives are being deployed to bring back this iconic species and the associated ecosystem, but Belgium is trailing behind this wave of renewed interest in flat oyster restoration. However, with the UNITED project, a first and important initiative has started to restore flat oyster reefs in the BPNS. UNITED (2020-2023) is a research project co-funded by the European Union’s Horizon 2020 programme. The acronym UNITED stands for Multi-Use offshore platforms demoNstrators for boostIng cost-effecTive and Eco-friendly proDuction in sustainable marine activities. By installing specific test pilots at five different marine sites in five European countries, UNITED aims to assess the feasibility and added value of marine multi-use. The Belgian pilot focuses on a combination of flat oyster restoration and aquaculture, and sugar kelp (Saccharina latissima) aquaculture in an offshore wind farm. Belgian offshore wind farms might offer a unique environment for both flat oyster aquaculture and restoration. Bottom-disturbing activities such as trawling are forbidden here, while the scour protection around the wind turbine foundations might serve as a suitable substrate for oyster settlement. Recruitment from the aquaculture individuals can initiate and sustain natural oyster reef development on this scour protection, and as such restore a lost ecosystem in the BPNS. An overview of the oyster restoration activities within UNITED will be presented, including the latest, promising results of the nearshore experiments and the successful offshore (within an offshore wind farm) installation of oyster restoration structures, which house broodstock animals. Before moving offshore, the nearshore experiments have tested and optimised the restoration structures and investigated the settlement of flat oyster spat on different materials as well as the survival, growth and reproduction of flat oysters in aquaculture systems