ENJOY your cod and chips while you can, because the combined efforts of the European Commission and global warming may soon spell the end for these fish in the North Sea. For the second year running, the European Commission has ignored scientists’ pleas for cod fishing in the North Sea to be halted.
Stocks are so depleted, the scientists say, that continued fishing could drive the cod into local extinction. Even stopping fishing now might not be enough, as evidence published this week shows that it is not just overfishing that is destroying the cod. Rising sea temperatures caused by global warming may also be playing a part, by eliminating the fish’s preferred food.
Last year, the International Council for the Exploration of the Sea (ICES) in Copenhagen advised that the population of North Sea cod could be doomed unless all cod fishing ceased in 2003. European Union fisheries ministers responded by merely cutting the cod quota by 65 per cent. This year, ICES repeated its demand, but last week the Commission decided to recommend the same catch for 2004 as for 2003.
Advertisement
The Commission says the decision is justified because cod stocks have not noticeably fallen this year. But Hans Lassen, chief fisheries adviser at ICES, says that cannot be known for certain. The population is so small any catch could have a disastrous effect on the remaining stock, he insists. “The only safe catch is zero catch.”
Even then, cod could still be in trouble. Gregory Beaugrand of Lille University of Science and Technology in France and colleagues, who have studied a detailed long-term record of plankton in the North Sea, found significant correlations between changes in plankton populations and the survival of larval cod. “I’m surprised no one has looked at this before,” Beaugrand told 91av.
Beaugrand has found that a cold-water species of copepod plankton once bloomed in the North Sea in spring, just when baby cod need food of that size. But since 1980 these plankton have been replaced by a warmer-water copepod that blooms in late summer, when baby cod need larger food. Another kind of plankton essential for providing vitamin A has also diminished.
“There is a major reorganisation of the plankton biodiversity of the North Sea ecosystem,” says Beaugrand. “All the changes are negative for cod.” He calculates these changes might explain half the drop seen since 1980 in the number of cod surviving to adulthood.
Before then, the plankton environment was very good for cod, Beaugrand says, and this may have allowed the fishing fleets to get away with ever-increasing catches. But as warming continues, things will worsen, he warns. “One could ask if the cod will recover, even with no fishing.” With continued fishing, “I’m pretty sure we will see local extinction in a couple of years,” he says.
Yet EU fisheries ministers seem likely to approve just that later this month. The Commission says its proposed quota will “ensure the continuity of economic activity in the fisheries”. It does not say how that economic activity will survive the extinction of the North Sea cod upon which it depends.