Fisheries, Not Whales, To Blame For Shortage Of Fish

ScienceDaily — The argument that increasing whale populations are behind declining fish stocks is completely without scientific foundation, leading researchers and conservation organizations said in June as the International Whaling Commission opened its 60th meeting in Santiago, Chile.

The Humane Society International, WWF and the Lenfest Ocean Program today presented three new reports debunking the science behind the ‘whales-eat-fish’ claims emanating from whaling nations Japan, Norway and Iceland. The argument has been used to bolster support for whaling, particularly from developing nations.

“It is not the whales, it is over-fishing and excess fishing capacity that are responsible for diminishing supplies of fish in developing countries,” said fisheries biologist Dr. Daniel Pauly, director of the University of British Columbia Fisheries Centre.

“Making whales into scapegoats serves only to benefit wealthy whaling nations while harming developing nations by distracting any debate on the real causes of the declines of their fisheries.”

Who’s eating all the fish? The food security rationale for culling cetaceans, the report co-authored by Dr Pauly for the Humane Society International contrasts “the widely different impacts of fisheries and marine mammals” with fisheries targeting larger fish where available and marine mammals consuming mainly smaller fish and organisms.

“The decline of the mean trophic levels of fisheries catch over the past 50 years is a signature of fishing down marine food webs and leaves marine mammals exonerated,” the report said.

The report also probes the culling whales increases food security for the poor argument by examining the final destination of catches of coastal fisheries in the South Pacific, Caribbean and West Africa. With less than half the catch going to domestic markets and the majority “gravitating toward the markets of affluent developed countries, one can speak of fish migrating from the more needy to the less needy”.

Also presented to the IWC Scientific Committee was the preliminary results into analysis of the interaction between whales and commercial fisheries in north west Africa. The modeling, funded by the Lenfest Ocean Program, shows no real competition between local or foreign fisheries and great whales.

The whales spend only a few months in the area during their vast seasonal migrations, eat relatively little while breeding and tend to consume fundamentally different types of food resources than the marine species targeted by both local and foreign fisheries. Inserting modelling assumptions to presume that whales are not breeding in the area and eat species important to the fishing industry still fails to show whales are a significant source of competition to fishing.

Also released today is review of the scientific literature originating from Japan and Norway - the two countries most strongly promoting the idea that whales pose problems for fisheries. The review, funded by WWF, found significant flaws in much of the science and concluded that “where good data are available, there is no evidence to support the contention that marine mammal predation presents an ecological issue for fisheries.”

Dr. Susan Lieberman of WWF said “These three reports provide yet more conclusive evidence that whales are not responsible for the degraded state of the world’s fisheries. It is now time for governments to focus on the real reason for fisheries decline – unsustainable fishing operations.”

Source: http://www.sciencedaily.com/releases/2008/06/080629144231.htm