Pacific species set to invade Arctic
Friday, 08 Aug 2008 00:07
The Arctic could become home to species from the Pacific, study says
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As global warming causes the temperature of the Arctic Ocean to rise the waters are set for an invasion of animals from the Pacific Ocean, a new study has claimed.
Species set to move north include shellfish and snails, and at least 77 molluscan lineages - about a third of the species of shallow-water shellfish in the Bering Sea - have the potential to spread to the Atlantic.
The migration is not entirely new for the species; their ancestors were on the move until they were interrupted by cooling conditions three million years ago, according to the study published in the journal Science.
Researchers from the University of California, Davis, and the California Academy of Sciences argue that the predicted warmer Arctic Ocean by 2050 will have restored conditions that last existed about three to 3.5 million years ago.
They claim that several north Pacific species have relatives in the north Atlantic, and the fossil record shows a lot of invasion from the Pacific to the Atlantic at that time.
When cold conditions returned, the Arctic route was cut off, mostly by a lack of food.
As the ice melts, productivity in the Arctic will rise and the northward march of the mollusks will resume where it left off three million years ago.
The researchers do not believe that the invasion of the new species will necessarily lead to the decline of native species.
The fossil record shows that invasions rarely lead to species extinction in marine environments, said researcher Geerat Vermeij. Instead, the invasion will add new species and hybrids and increase competition in the North Atlantic.
Co-author Peter Roopnarine added: "The composition and dynamics of north Atlantic communities will change.
"But whether that will help or harm local fisheries is an open question. Humans may have to adapt as well."
