Northern fish stocks in good shape

FISH stocks in the North Sea and Barents Sea, two of the most important northern hemisphere fishing areas, are in good shape, according to the latest assessment by marine scientists.
But there is evidence that the seas in those areas are becoming warmer.
The Norwegian Institute of Marine Research has been studying the state of several different types of fish.
It has found that in the North Sea the mortality rate has declined over the past ten years to a position where stocks have increased to such a level that they are now giving a high, long term yield.
However, with the discovery of anchovy larvae along the coast of Denmark and into the Skagerrak area, it is also picking up evidence of warming in the North Sea.
The IMR report adds that only time will tell if southern (warmer water) fish species are becoming more numerous in the North Sea.
There have been earlier reports of sea warming. The changes in the mackerel stock are linked to the fact that the Norwegian Sea continues to be warmer than ‘normal’.
But there has also been a growth in the stock, which means the fish need larger feeding areas. The decline in herring has been put down to poor recruitment.
The Barents Sea, so often seen in the past as the ultimate in cold fishing zones, is also becoming warmer, with the result that there has been a large reduction in sea ice over the past 15 years, says the IMR.
This has led to a reduction in mortality and an increase in cod stocks, which are still in good shape. It is the same picture for haddock and saithe.
Another side effect has been the discovery of good snow crab stocks on the west wide of Svalbard (Spitzbergen) which, as reported on Fish Update, has led to a dispute between Norway and Polish and Baltic crab fishermen.