Assessing the state of marine biodiversity in the Northeast Atlantic

The Northeast Atlantic has been exposed to a wide range of direct human pressures, such as fishing, shipping, coastal development, pollution, and non-indigenous species (NIS) introductions, in addition to anthropogenically-driven global climate change. Nonetheless, this regional sea supports a high diversity of species and habitats, whose functioning provides a variety of ecosystem services. As part of the 2023 OSPAR Quality Status Report, here,for the first time, we use a semi-quantitative approach to evaluate holistically the state of Northeast Atlantic marine biodiversity across marine food webs, from plankton to top predators, via fish, pelagic and benthic habitats, including xeno-biodiversity. Our analysis reveals widespread degradation in marine ecosystems and biodiversity, which is likely the result of cumulative effects of multiple human activities, such as overexploitation, the introduction of NIS, and climate change. Bright spots are also revealed, such as recent signs of recovery in some fish communities and recovery in harbour and grey seal populations in some regions. The status of many indicators, however, could not be assessed due to gaps in data, unclear pressure-state relationships, and the non-linear influence of some pressures on biodiversity indicators. Lessons learned will drive progress towards a better integrated assessment of wide-scale marine ecosystems.