Vulnerable Corals and Critically Endangered Clams

Marine invertebrates represent the greatest biodiversity in our oceans, yet they’re often underrepresented in conservation efforts. But we’re trying to change that! SOSA coordinated the addition of 34 marine invertebrates to the IUCN Red List, including all 12 giant clam species and 22 cold-water corals!

But it’s not all good news. Alarmingly, half of all giant clams are at risk of extinction, largely because of overfishing.

The largest clam, Tridacna gigas, can weigh up to 200kg and live over 100 years!  Once a common resident of warm-water (shallow) coral reefs, the population of this giant species is now alarmingly small in the wild – largely due to overharvesting as a food source or as a sought-after ornament. Due to these threats and dwindling population, Tridacna gigas was assessed as Critically Endangered, a category of organisms considered to be facing extremely high risk of extinction in the wild. 3 other clam species were listed as Endangered, 2 as Vulnerable, and 3 as Data Deficient.

Cold-water corals are also facing threats but fared slightly better in the assessments. Over 40% of the 22 species assessed are facing some threat of global extinction.

Cold-water corals, while often less known than their tropical reef cousins, are important habitat builders in deep-sea ecosystems, supporting large amounts of biodiversity. Stony coral reefs are extremely slow-growing, but can live for thousands of years. Threats to cold-water corals are immense, with bottom trawl fishing being the most urgent, yet the data we have on these animals is scarce. The species we know most about, Desmophyllum pertusum, received the highest threat category among the assessed cold-water corals – Vulnerable, a category of organisms considered to be facing a high-risk of extinction in the wild. Bottom trawling was estimated to have damaged 30-50% of regional reefs, and with a slow-to-grow and thus slow-to-recover species like Desmophyllum pertusum, the risk of global extinction is high. 8 other coral species were assessed as Near Threatened, 10 were Least Concern, and 3 were Data Deficient.

The IUCN Red List of Threatened Species is an important tool in the protection and conservation of species and biodiversity by providing objective information that communicates threats, informs policy, influences resource allocation and shapes decision-making of conservation efforts worldwide. As part of the SOSA project’s efforts to increase the number of assessed marine invertebrates on the IUCN Red List, the team coordinated 37 different researchers and assessment experts to complete the 34 Red List assessments included in the most recent update. The project’s ongoing efforts coordinate marine invertebrate assessments from taxa not currently supported by a Red List specialist group as well as serves as a support service for researchers needing assistance in successfully assessing and listing their marine invertebrate species.

Learn more about SOSA’s efforts to include more marine invertebrates on the IUCN Red List here: https://sosa.senckenberg.de/en/protect/

Check out the IUCN Red List of Threatened Species here: https://www.iucnredlist.org/

Check out some of the assessed animals below!