The Global Marine Species Assessment (GMSA)

The central initiative of the Marine Biodiversity Unit (MBU) is the completion of the Global Marine Species Assessment (GMSA) – assessing the extinction risk of 20,000 marine species for inclusion on the IUCN Red List of Threatened Species using the IUCN Categories and Criteria. This project was initiated in 2005 by the IUCN Species Survival Commission and is producing species-specific baseline data and comprehensive analyses needed to develop targeted and coordinated marine conservation planning and action at global, regional, and national scale. Priority species groups for assessments include all of the world’s known marine vertebrates; primary habitat producers such as corals, seagrasses and mangroves; and selected invertebrate families of crustaceans, echinoderms, and molluscs.

Assessments are typically accomplished in a workshop setting that allows for MBU-facilitated application of the IUCN Red List Categories and Criteria by scientific experts across disciplines including taxonomy, fisheries science, marine ecology, and marine conservation. Following a workshop, the resulting data is peer-reviewed and made freely available for download on the IUCN Red List of Threatened Species.



Our team of marine scientists continues on toward the ultimate goal of assessing the global conservation status of 20,000 marine species. Over 14,000 marine species are now represented on the IUCN Red List. Major completed taxonomic groups include all of the world’s known marine mammals, sea turtles, sharks and rays, sea snakes, corals, mangroves, seagrasses, tunas and billfishes, and numerous fish families. The Global Marine Species Assessment initiative has substantially increased the representation of marine species assessed under the IUCN Criteria and published on the IUCN Red List.

Resulting analyses have been widely shared as publications in peer-reviewed scientific journals (including high-profile publications in the prestigious journal Science), book chapters and popular reports. Thus far, approximately 11% of all marine species assessed have an elevated risk of extinction (listed on the IUCN Red List of Threatened Species as Critically Endangered, Endangered, or Vulnerable).