In the February issue of Nature, Point/Counterpoint the journal debates “catch data” as a vital tool for assessing the health of fish stocks. What we pull out of the water is not a viable account of what is actually going on in the fishery.
Ray Jilborn and Trevor Branch warn that over-reliance on this type of assessment misses the entire point altogether. Catch data misses important subtleties and misleads the health of entire ecosystems down to a landed tonnage.
Both commentaries discus the information published by the Food and Agriculture Organization
The data is collected from 200 countries on the amount of weight, haddock, bream and cod get hauled in by fishing boats. The number of fish caught doesn’t tell us about the number of fish in the sea. New fishing regulations can reduce catch but fishermen may decide not to fish because gas prices are high or the price of fish is low.
“Attempts to use this data as a method of deciding whether or not a fishery is successful, rebuilding, exploited or collapsing is spreading alarm and confusion in policy and serious public debate about fishing amongst conservation organizations and that fishery management is failing. The two authors wrote, “A much better way to deduce the health of stocks region by region and fishery by fishery, is to collate all sorts of data-for instance scientific data about 40% of the world’s fisheries comes only from developed countries.” The Food and Agricultural Organization and the World Bank estimate it could take as long as ten years to collect the proper data from each country, not to mention $20 million
Expert stock assessments require expert stock research vessels which cost around around $50,000 to the millions
“What is needed is a lot of hard work. Going to different fisheries with officials and fishermen to understand the fisheries that are not being evaluated.
Nature writes, “It is unquestionable that some fisheries have been horribly mismanaged, and some species driven to very low levels.” Both Hilborn and Branch agrees. “But equally there are positive signs of change. There are well-managed fisheries and more importantly a politician who will listen to scientists.”
How many fish are there?