A new study published in the journal Science shows there are ways to successfully manage fisheries to stop over-exploitation of fish stocks allowing for continuous sustainable fishing.
Three years ago Dr. Boris Worm, a marine ecologist at Dalhousie University in Canada and Ray Hilborn, a professor of aquatic and fishery sciences with the University of Washington, disagreed severely on Boris Worm’s prognosis that the oceans could run out of fish by 2048 if overfishing wasn’t stopped (scroll down for the link to his article).
A Dalhousie article describes how these two renowned scientists got together to study fish abundance and exploitation rates in ten different ecosystems where steps were taken to decrease overfishing. They also studied the tools fisheries managers had applied to make this happen.
The resulting analysis showed that in five of 10 well-studied ecosystems, the average exploitation rate has declined and, for seven of the systems, is at or below the rate needed to achieve maximum sustainable yield.
“I think the most important contribution was compiling stock assessments and trawl surveys, because these both directly measure the biomass, or abundance, of fish stocks,” says Trevor Branch, UW research scientist in aquatic and fishery sciences and co-author on the paper. “Previously, scientists and coauthors in 2006 tried to measure the status of world fisheries based only on catches.
“We didn’t look only fishery by fishery, we also looked ecosystem by ecosystem,” explains Dr. Worm. “One of the novel things we did here was find out whether the pressure we put on ecosystems by fisheries is going up or down and the good news is that the pressure on the ecosystem is decreasing overall in half of the ten systems we have detailed data for.
” While it may seem like a glass half-empty or half-full debate, the findings give Dr. Worm a renewed hope that if proper, timely management is applied, fish stocks can be rebuilt. “I think it gives us hope that something can be done and it’s not just an idea as we now have the results to show the world.”
A diversity of solutions are recommended by the scientists: reducing catches, closing certain areas, regulating fishing gear and reducing the capacity of fishing fleets, restructuring incentives, creating programs like catch-shares that offer fishermen stock in the overall catch, so it’s in their best interest to not only make sure they don’t overfish but that others don’t as well. Each area will have create solutions specific to that ecosystem.
Places like Alaska, California, New England, Iceland and New Zealand have been successful with their measures and their approach to conserve their fish stocks. Even developing countries like Kenya are producing results that are not only good for the ecosystem but also for fishermen.
“We don’t want to spread complacency but I also worry about the people who think it’s hopeless – we have to be able to show why it’s worth taking action,” Dr. Worm says.
“These highly managed ecosystems are improving,” Hilborn says. “Yet there is still a long way to go: of all fish stocks that we examined, 63 percent remained below target and still needed to be rebuilt.”
“I’m very happy we did this, that it’s worked out and we got together and hammered out our differences,” Dr. Worm explains. “I think it’s good for the respective fields because we need to move forward together. After all, there is only one world and we better work on that world together.”
The findings were published in the July 31 issue of Science: “Rebuilding Global Fisheries” and were co-authored by a team of 19 scientists.
Read the full article at Dalhousie University
Read Boris Worm’s original article here.
Copyright © 2009 by Marine Science Today, a publication of OceanLines LLC