The first global snapshot of marine life shifting under climate change has found it is on the move towards the poles at a rate of about seven kilometres a year. Fish and other marine creatures are seeking cooler habitat much faster than terrestrial life, according to an international study published in the journal Nature Climate Change.
In Australia, this re-shaping of the marine ecosystem will have significant repercussions for people such as fishers, according to CSIRO marine ecologist and study leader Elvira Poloczanska.
Dr Poloczanska, of the University of Queensland, and 18 international colleagues found no doubt about who was responsible for the greenhouse gas-related warming of the ocean’s upper layers. “Global responses of marine species revealed here demonstrate a strong fingerprint of this anthropogenic [caused by humans] climate change on marine life,” the paper said.
Dr Poloczanska said in Australia’s south-east, tropical and subtropical species of fish, molluscs and plankton were shifting much further south through the Tasman Sea.
A 2010 CSIRO study found that warm surf-zone species such as silver drummer were more abundant, while the range of others such as snapper and rock flathead has increased.
In the Indian Ocean, a southward distribution of seabirds has been detected, as well as a loss of cool-water seaweeds north of Perth.
The latest study assembled a data base of 1735 marine biological responses around the world, where climate change was considered to be a driver in species movement.
“The leading edge or ‘front line’ of a marine species distribution is moving towards the poles at the average rate of 72 kilometres per decade,” Dr Poloczanska said. “This is considerably faster than terrestrial species moving poleward at an average of six kilometres per decade . . . despite sea-surface temperatures warming three times slower than land temperatures.”
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