The MARISCO project, running from 1 June 2020 to 31 May 2023 for the German component and extending to June 2024 for its international partners, aimed to clarify how human activities alter coastal and oceanic ecosystems and to translate those insights into practical management tools. The German lead partner, the Carl‑von‑Ossietzky University of Oldenburg (UOL), coordinated three of the five work packages (WPs) while collaborating with the University of California, Santa Barbara (UCSB) and Nelson Mandela University, South Africa (NMU). Funding came from the Belmont Forum’s Collaborative Research Action for Ocean Sustainability (CRA Ocean) and, for the U.S. partner, from the National Science Foundation.

In WP 3, the team performed a comprehensive meta‑analysis of global studies on biodiversity change, building on the 2020 publication by Hillebrand et al. The analysis quantified average effect sizes of anthropogenic drivers on ecosystem properties, providing a benchmark for regional comparisons. Using structural‑equation models, the project linked four biodiversity metrics—species richness, functional diversity, taxonomic composition, and community heterogeneity—to environmental variables such as temperature, pH, and nutrient availability. The models revealed that biodiversity responses vary markedly among organism groups; no single index adequately captures the multivariate nature of change. Consequently, the team concluded that threshold and tipping‑point concepts, while useful for other ecological questions, are poorly suited to describe biodiversity dynamics and should be replaced by multivariate monitoring frameworks. These findings were published in Hillebrand et al. (2023) and are under review in Frontiers in Ecology and the Environment (Dajka et al.). The open‑access data set for the Wadden Sea (Wattenmeer) has been released, while data for the Algoa Bay case study are pending harmonisation by South African monitoring authorities.

WP 1 focused on transdisciplinary knowledge integration. After UOL’s entry, the team selected metrics for stressor identification and biodiversity assessment, with contributions from NMU and UCSB. WP 2 developed scenario analyses, led by UCSB, and incorporated input from UOL and NMU. WP 4 conducted systematic literature reviews on stakeholder engagement, and WP 5 translated scientific insights into management recommendations. A vulnerability assessment framework for organism groups was established, and a workshop on vulnerability metrics was held in February 2022, with a final project workshop scheduled for summer 2024.

Stakeholder engagement was extensive. The project organised multiple workshops and deliverables meetings, including a stakeholder workshop on 28 Aug–3 Sep 2022, a public presentation at the 2022 INTECOL conference, and a policy briefing for the German Marine Protection Commissioner in Berlin (27 May–21 Jul 2023). Collaborations with the Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten‑ und Naturschutz (NLWKN) and the Nationalpark Wattenmeer produced targeted talks and data exchanges. The German Science Service (GSS) partner, Alifaire Noreen, produced a policy brief and fact sheet summarising MARISCO’s results for policymakers.

Overall, MARISCO delivered a robust, multivariate framework for assessing biodiversity responses to global change, demonstrated the limitations of threshold‑based approaches for biodiversity, and produced actionable guidance for marine managers. The project’s transdisciplinary design, international partnership, and policy‑oriented outputs exemplify how scientific research can inform sustainable coastal and ocean governance.