You鈥檝e heard of offsetting carbon. Well how about offsetting dead seabirds?
Many seabird populations are threatened because the birds end up as by-catch in commercial fishing nets. If restricting fishing fails, the last resort is usually to close fisheries. Now two ecologists claim that a better way may be 鈥渂iodiversity offsetting鈥� 鈥� placing a levy on by-catch and using the money to pay for alternative conservation efforts.
Chris Wilcox of Australian national research organisation CSIRO in Hobart, Tasmania, and Josh Donlan of Cornell University in Ithaca, New York, tested the approach by modelling a population of flesh-footed shearwater (Puffinus carneipes) on Australia鈥檚 , which is threatened by fishing and rats.
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They simulated either banning fishing within 750 kilometres of the island or using levies from the fishers to eradicate rats. In both models, the population鈥檚 annual growth rate increased by more than 60 per cent over 20 years, but whereas banning fish cost US$3 million in lost revenue, eradicating rats cost $500,000 ().
Almost half of the birds listed as endangered by the World Conservation Union are threatened by fishing, and as many as two-thirds of those are also threatened by an invasive species, Wilcox points out. By-catch levies have the additional advantage of giving fishers an incentive to avoid by-catch by using innovative fishing techniques. It would also avoid the 鈥渞ace to fish鈥� when a fishery closure is anticipated.
