The IUCN Species Survival Commission (SSC) has a new Specialist Group, created in June 2023: the Marine Star Specialist Group, focusing on the asteroids (sea stars), ophiuroids (brittle stars), and crinoids (feather stars and sea lilies). The new Specialist Group will strengthen the SSC's vision—to prevent the loss and aid recovery of biodiversity—by increasing its focus on marine invertebrates. Marine stars are found from shallow- to deep-water marine habitats, including extreme environments such as seamounts, hydrothermal vents, cold seeps and anchialine caves.
Of almost 5,000 species, only the sunflower sea star Pycnopodia helianthoides has so far been assessed for the IUCN Red List, as Critically Endangered. It has also been proposed as threatened under the Endangered Species Act in the USA and is being assessed for listing with the Committee on the Status of Endangered Wildlife in Canada. This sea star is threatened by sea star wasting disease. This causes lesions, disintegration and death of the affected animals and has also been observed in more than 20 other sea star species along the west coast of North America and Antarctica; densities of the red sea star Odontaster validus recently dropped by 10% around Deception Island and by 50% to > 80% at two locations in McMurdo Sound, Antarctica.
None of these sea stars have had their Red List status assessed. Other sea star species have also undergone catastrophic population losses, including the unassessed Gulf sun star Heliaster kubiniji, which saw major declines in the late 1970s that were worsened by climate change. Sea stars can be highly endemic and therefore suffer from acute threats to their habitat. For example, the sea star Marginaster littorialis is listed in Australia as Critically Endangered and according to experts may even be extinct. Comparatively little is known about the conservation status of brittle stars, feather stars and sea lilies. For instance, 11 species of brittle stars and four species of sea stars have been found in anchialine caves, but none have been assessed for the IUCN Red List.
There is a clear need for marine star assessments, given the keystone role many of these species play in their respective ecosystems. The Marine Star Specialist Group will collaborate with the SSC's Marine Invertebrate Red List Authority and Sea Cucumber Specialist Group to train its members in Red List assessments and coordinate assessments of marine stars. The Group will also focus on conservation planning for marine stars and undertake and inspire actions to conserve these species in the face of climate change, emerging marine infectious diseases, invasive species, habitat destruction through coastal development, runoff pollution, eutrophication, deep seabed mining and fishing activities. We need more experts to join us in this venture.
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