One Ocean Science Congress 2025

• Session T2-3: Ocean-based renewable energy such as offshore wind, solar, wave, thermal and tidal energy, Tuesday 3 June, 14:00–15:00 (EST), Room 5

In response to the urgency of combating climate change, there is a growing interest in exploring ocean-based carbon dioxide removal strategies and alternative renewable energy sources, as well as adaptation and resilience-building interventions for natural and human systems. However, the potential benefits, side-effects and risks associated with these strategies and options remain largely unknown, both for marine ecosystems and for society at large.

• Session T9-1, Environmental footprint of maritime transport and decarbonization of shipping, Thursday 5 June, 16:00–17:30 (EST), Room 6

Fostering a comprehensive approach to shipping to address the triple planetary crises of climate change, pollution and biodiversity loss will be essential. In addition to decarbonisation, what more can be done to assess, reduce and avoid negative impacts on marine biodiversity in ports and globally?

Using methodology developed for the 2023 OSPAR assessment of Pelagic Habitats, we analysed 29 years of Continuous Plankton Recorder data from the North-East Atlantic to examine how temperature, nutrients and background environmental variability impacted abundance.

We project changes to two vital pelagic ecosystem services, carbon export and fisheries, with future plankton ecological changes. We coupled an empirical approach based on pelagic size structure (the relative biomass of large and small organisms), coupled to projections from two Earth System Models to estimate changes in the supportable biomass of fish and in carbon export efficiency under CMIP6 high emissions scenarios.

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.