Sunday, March 22, 2009

Marine Life & Climate Change: possible species invasion & extinction recently reported on a study published in the journal Fish and Fisheries which provided projections as to marine species invasion and extinction due to climate change, specifically the increasing ocean temperatures. The projections were based on climate change models including those of the Intergovernmental Panel on Climate Change. The results of William Cheung and his colleagues at Canada's University of British Columbia were also presented at a recent Chicago meeting of the American Association for the Advancement of Science.

What the report postulated was that with increasing ocean temperatures, many marine species would migrate towards the temperate to sub-polar regions. Extinctions would occur in tropical regions because of a species inability to migrate, while species in colder waters would be faced with both the same negative impact due to temperature increase plus the impact of invasive species (increased predation and competition). Semi-closed bodies of water (ex: the Mediterranean, the Red Sea), could experience high levels of extinction because of the species' inability to migrate due to geography.

The study pointed out the rate of extinction would be much lower than for terrestrial animals, the theory being that marine animals have a higher dispersal ability and can more easily migrate to suitable habitats. However, the impact by and to human populations can also enter into all of this in the form of decreased fishing in low income tropical economies - economies that depend on seafood on a very basic subsistence level, and in decreased fish populations in colder waters due to industrialized fishing for moderate to high income economies.

We often look to the Arctic and Antarctic for critical signs of climate change, indicators of profound changes. But we must realize it is a worldwide change which challenges all of nature, including man, on many different levels.

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