Researchers assess status of slimy scavengers of the seafloor
Hagfish, eel-like creatures known for secreting buckets of slime, are among the ocean’s most ancient species. They dwell on the ocean floor feeding on dead and dying sea life, filling an important ecological niche. Human activities, however, may be threatening their numbers and new research looks into the population decline of these shadowy creatures.
“By consuming the dead and decaying carcasses… hagfishes clean the ocean floor, creating a rich environment for other species, including commercial ground fish such as codfish, haddock, and flounder,” writes Old Dominion University’s Landon Knapp and five colleagues in Aquatic Conservation. Commercial fishing may be killing off hagfish, however, by destroying their habitats and reeling them in as “by-catch.” Meanwhile, an emerging eel-skin market is creating a growing demand for hagfish skins. Declining hagfish populations could result in lasting ecological damage, even affecting table fish: Data shows that when commercial fishers went after some hagfish populations, “the stock of other commercial species such as flounder plummeted.”
To determine humankind’s impact on these evolutionary ancestors, researchers assessed data on 76 known species. The team then used the International Union for Conservation of Nature’s (IUCN’s) Red List Categories and Criteria to classify the threat face by each species.
One hagfish species is “critically endangered” and two “endangered,” the researchers concluded. Six more are “vulnerable.” There was not enough data to classify 30 species under the IUCN criteria, but the research team concluded that 23 of these were facing “significant major threats such as trawling, bycatch, targeted fisheries, or habitat degradation.”
“Better fisheries statistics, including catch landings and recorded bycatch of hagfish species, is needed to determine not only the impact of extensive trawling on hagfish populations, but also to better determine species distribution and population trends,” the researchers suggest. And they call for new hagfish conservation laws, noting that “no current conservation measures or legislation exist to protect the survival of hagfish populations throughout the world’s oceans.” – Matthew Dieter | July 21, 2011
Source: Landon Knapp, Michael M. Mincarone, Heather Harwell, Beth Polidoro, Jonnell Sanciangco, and Kent Carpenter (2011). “Conservation status of the world’s hagfish species and the loss of phylogenetic diversity and ecosystem function.” Aquatic Conservation: Marine And Freshwater Ecosystems. DOI: 10.1002/aqc.1202
Image Pacific hagfish, NOAA Fisheries