Charles Clover, The Telegraph 17 Jan 08;
There are more species of fish in the North Sea as a result of rising water temperatures, but the changes are unlikely to please fishermen overall, scientists have said.
The reason is that while the number of bottom-dwelling fish species has increased by half since 1985, in response to a temperature increase of almost 1.5 °C, most of the new additions are of little commercial value.
Some of the new species, such as anchovies and red mullet, are a welcome addition to trawler catches but this will not compensate for the large valuable species such as wolffish, spurdog and ling which are moving to the north, according to the study published in the journal Global Change Biology.
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The authors, Jan Hiddink of Bangor University in Wales and Remment ter Hofstede of Wageningen IMARES in the Netherlands, say similar changes are probably under way in other northern waters.
'This research will help us understand and predict what the effect of climate change on biodiversity will be.
"Fishery managers will have to adapt their practices to a fishery with many small species rather than a few large species', according to Dr Hiddink from Bangor university.
Increases in fish species richness depend on easy migration of fish species from the south, and higher species numbers to the south. According to EU scientists, though, the Bay of Biscay anchovy has been significantly overfished.
