New Species of Coral

Fisheries have moved into the deep sea over the last 30 to 40 years, and bottom fishing using trawls, longlines and other gear takes place at depths in excess of 2,000 metres. Deep-sea fish species are very slow growing and live to ages greater than 100 years, resulting in a high level of vulnerability to overfishing. Bottom fisheries deploying trawls have been found to have a devastating impact on fragile seabed communities, such as cold-water coral reefs. However, much less is known about the impacts of other fishing methods on deep-sea ecosystems, especially longlining, which is being used increasingly as an alternative to trawling.

In collaboration with fisheries managers, ZSL scientists are currently studying the bycatch of deep-sea longline fisheries for Patagonian toothfish in South Georgia. The bycatch comprises many corals that are extremely difficult to identify because their classification is poorly understood. However, by using a combination of molecular methods and careful analyses of the shape of the corals, especially their polyps and sclerites, the corals are now being indentified. This work has resulted in the revision of the classification of an ecologically important group of corals: the primnoids, especially the genus Thouarella. It has also led to the discovery of six new species, many of which are extremely beautiful. The work has enhanced current understanding of the biodiversity of marine ecosystems in the Sub-Antarctic and the evolution of primnoid genera.