A new study helps explain a cyclic increase and decrease of jellyfish populations, which transformed parts of the Bering Sea--one of the U.S.'s most productive fisheries--into veritable jellytoriums during the 1990s.
The study shows that the availability of food for jellyfish may cap the potential size of the Bering Sea's jellyfish population, even while other factors, such as rising temperatures, may encourage its continued growth.
These results indicate that "anticipated temperature increases in the Bering Sea will not necessarily further increase its jellyfish populations," says Lorenzo Ciannelli of Oregon State University, a co-author of the study. By contrast, in warmer latitudes, jellyfish frequently multiple as temperatures rise.
The study provides potentially good news for the Bering Sea's fishing industry, which has been damaged by jellyfish blooms. Nicknamed "America's fish basket," the Bering Sea produces more than half of the U.S.'s entire catch of fish and shellfish.
Described in the May 29, 2008 online issue of Progress in Oceanography and summarized online in Nature, the study was partially funded by the National Science Foundation (NSF).
The Rise and Fall of Jellyfish
During the 1990s, the Bering Sea's jellyfish reproduced with such wild abandon that by about 2000, they were about 40 times more abundant than they had been in 1982, according to analyses of collections from fishing trawls made in the Bering Sea by the Alaska Fisheries Science Center. In addition, starting in 1991, Bering Sea jellyfish expanded their ranges by fanning out north and west of the Alaskan Peninsula.
Because of these changes, one area north of the Alaskan Peninsula--always famous for its jellyfish--became so jellified that fishermen nicknamed it "Slime Bank" and began avoiding it altogether for fear of filling their nets with jellyfish. Other fisheries were damaged as well.
The Bering S
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National Science Foundation