IUCN metric to help quantify progress towards global ocean biodiversity targets

The Species Threat Abatement and Restoration (STAR) metric uses existing data on extinction risks and threats faced by species, taken from the IUCN Red List of Threatened Species™, to quantify how much targeted threat-abatement actions in specific places can minimise further risks to biodiversity and species. It was first unveiled in 2021 by IUCN and a consortium of biodiversity experts for use in terrestrial areas, and has now been expanded for use in marine areas – which are megadiverse and heavily affected by human activities such as overfishing, pollution, and habitat loss, which has also been exacerbated by climate change.  

The launch of Marine STAR is detailed in a new publication in the npj Ocean Sustainability journal, which was co-authored by several IUCN experts, including Chief Scientist Tom Brooks, Ocean Team Director Minna Epps, and Policy and Science Advisor Frank Hawkins.

“Effectively halting [marine] biodiversity loss requires quantifying how protected areas contribute to biodiversity conservation and targeting the specific actions which would deliver genuine benefits for biodiversity,” they explain in the paper. “The production of appropriate marine biodiversity metrics and tools is therefore crucial to engage with and guide decision-makers, businesses, and civil society.”

The Marine STAR metric includes data on 1,646 species ranging from corals to sharks, and identifies areas where mitigating threats could reduce species extinction risk over the global marine realm.

The metric's expansion to marine areas allows governments, businesses, and financial institutions to better understand whether their actions are helping meet specific goals laid out international agreements like the Kunming-Montreal Global Biodiversity Framework (GBF), approved in December 2022, and the global Sustainable Development Goals. Target 3 of the GBF, for example, calls on the international community to conserve 30% of land, waters, and seas by 2030, while Target 4 calls for the ending of human induced extinction of known threatened species.

According to Marine STAR, reducing unsustainable fishing would offer the greatest opportunity to lower species extinction risk, followed by better management of invasive and problematic species, along with addressing climate change that can shift and alter habitats and fuel extreme temperatures.

As it is developed further, STAR is also expected to provide important predictive abilities to support international treaties and agreements still in flux. During this crucial year for ocean conservation, ratification of the United Nations High Seas Biodiversity Treaty is being sought, negotiations continue this month on the World Trade Organisation’s Agreement on Fisheries Subsidies, and discussions will continue towards a new legally binding global treaty to end plastic pollution.