Benthos Ecology Working Group (BEWG).

The Benthos Ecology Working Group (BEWG) aims to study, describe and update on all aspects relevant to the ecology, functioning and interactions of marine benthic species (living in or within the sediment), either macro, meio and epifauna across the North Eastern Atlantic. This report contains the overview of ongoing initiatives covering central aspects of benthic ecol-ogy. The work is focussed on: benthic long-term series and climate change, benthic indicators, species distribution modelling, the link between biodiversity and ecosystem functioning and the role of benthos within MPAs. The work conducted over the past three years has concentrated on assessing the current challenges in methodological approached associated to the study of climate change and long-term benthic assessments. The BEWG is in the process of drafting a communi-cation paper, to showcase the benefits, challenges, and examples of benthic time-series usage. The work centres on the dedicated monitoring and assessments of benthic systems. Some of these assessments are challenged and compromised due to the lack of relevant samples, funding, and methodological changes over time (e.g. new equipment and/or new sampling design). The BEWG members are also participants of the EU EmodNET biology consortium, therefore keeping up to date with current and relevant data series initiatives. A case study is under de-velopment, assessing the level of variability in expert assessment of benthic species tolerances /sensitivities. This case study has been developed in consultations with over relevant ecological questions, dedicated assessments across ecologists, their training and their influences of their network in their assessments. The work on benthic indicators and effective monitoring pro-grammes (including design, harmonisation, and quality assessments) is progressing well and dedicated examples from all members were shared and discussed. The work on the relevant benthic indicators for ecosystem quality assessment, based on a functional indicator needs in support of the MSFD is still in draft and a sub-group will continue with intersessional work to report in 2021. A series of benthic, biological traits and sediment data sets has been compiled, the work aims to test what are the “changes in functional composition along sediment gradients”, which has been discussed and will be advance and reported in 2021. The benthic ecology and conservation work developed on the paper published this summer under the topic of “the role of benthos within MPAs” has been well received and actively disseminated