10 July 2014
Source: Phys Org
Decades of overfishing in the English Channel has resulted in the removal of many top predators from the sea and left fishermen ‘scraping the barrel’ for increasing amounts of shellfish to make up their catch.
Sharks, rays, cod, haddock and many other species at the head of the food chain are at historic lows with many removed from the area completely.
These are some of the findings of a study led by marine biologists at Plymouth University, in association with international non-profit research organization WorldFish. They analysed catches over the past 90 years and found significant evidence of the practice of ‘fishing down the food web’.
The report, published in the PLOS ONE journal, used catch statistics from the International Council for the Exploration of the Seas to establish a ‘mean trophic level’ for catches – an average for how far up the food chain the fish are located.
Professor Jason Hall Spencer, of the School of Marine Science and Engineering, and the Marine Institute, said: “It is clear from our analyses that fishing pressure has caused significant changes to food webs of the English Channel over the past 90 years. The mean Trophic Level of English Channel landings has fallen by 0.1 unit per decade, one of the fastest rates reported among other heavily fished regions of the world, providing yet more evidence that ‘fishing down food webs’ is a worldwide phenomenon.”