Some Species of Homely Hagfish Threatened with Extinction, Researchers Say
Researchers associated with Old Dominion University took part in a study released this week that could draw attention to deep-sea creatures that look about as homely as their name - hagfish - would imply.
The study conducted for The International Union for Conservation of Nature (IUCN) Red List of Threatened Species determined that at least nine of the 76 species of hagfish are at an elevated risk of extinction. Scientists warn that this figure could be much higher because not enough is known about many hagfish species to assess their current risk of extinction.
Hagfish, which look something like eels, represent an ancient and unique evolutionary lineage. As bottom feeders they play an important role by cleaning the ocean floor and recycling nutrients into the food web, which maintains the overall health of the ecosystems they inhabit.
"By consuming the dead and decaying carcasses that have fallen to the ocean floor, hagfishes clean the floor, creating a rich environment for other species, including commercial fish such as cod, haddock and flounder," said Landon Knapp, research assistant for the IUCN Marine Biodiversity Unit at ODU and lead author of the study. "The presence of hagfish in areas of intense fishing is extremely important, as large amounts of bycatch are discarded." Bycatch is the term for ocean creatures unintentionally caught up in fishermen's nets.
The results of the study indicate that the primary causes of hagfish declines are the direct and indirect effects of fisheries.
Particular areas of concern highlighted in the study include southern Australia, where the only hagfish species present is threatened, and the coast of southern Brazil. Also of concern are the species found in the East China Sea, the Pacific coast of Japan and coastal Taiwan, where four of the 13 hagfish species occurring in those areas are threatened with extinction.
"In many geographic regions, only one or two hagfish species are present, and therefore the loss or decline of even a single species in these areas will have detrimental effects on ecosystems as a whole, as well as the fisheries that depend on them," said Michael Mincarone, professor of zoology at Universidade Federal do Rio de Janeiro and an author of the study.
Fisheries worldwide directly profit from the harvesting of hagfish, such as Myxine garmani (vulnerable) and Eptatretus burgeri (near threatened), for leather and food. Hagfish are also an important part of the food chain, being prey for fishes, seabirds and even marine mammals, including seals. When fishing pressure was focused on hagfish in certain locations in the northwestern Atlantic, the stock of other commercial species, such as flounder, plummeted, according to the IUCN.
Overexploitation and destructive fishing practices are major threats to several hagfish species, and no current conservation measures or legislation exist to protect hagfish populations, the IUCN notes.
"Additional data are required and controls for the regulation and management of hagfish fisheries and other threats to hagfish populations are urgently needed to ensure the survival of these important species," said Kent Carpenter, professor of biological sciences at ODU and manager of IUCN's Marine Biodiversity Unit. Carpenter also is an author of the paper.
The biodiversity work is part of the Global Marine Species Assessment (GMSA) project that is headquartered at ODU and directed by Carpenter. GMSA is a joint initiative of IUCN, Conservation International and ODU, which has been working since 2005 to provide assessments of more than 20,000 species.