KEY POINTS:
At a time when a quarter of the world's fisheries are considered depleted, can commercial fishermen make more money by fishing less?
A study published in the latest edition of the journal Science says they can, with one condition.
They must be in a co-operative fishery, like those operating in New Zealand and Australia, where individual fishermen own a share of the total harvest - known as individual transferable quotas - rather than the competitive fisheries more common in the United States, where it is a race to catch the most fish.
The idea is that when there are more fish and no race to catch them, fishermen spend less on fuel and other costs chasing far and wide to fill their nets, and can concentrate on delivering a high-quality product to the dock, said lead author Quentin Grafton, research director at the Crawford School of Economics and Government at Australian National University.
Leaving more fish in the sea - a fishery management target called maximum economic yield - leads to higher profits than the traditional target known as maximum sustainable yield, the study said.
"We like to say it's a win-win," said co-author Ray Hilborn, professor of fishery sciences at the University of Washington. "You have fishermen making more money. You have ecosystems that are healthier. And you have more fish in the ocean."
The Food and Agriculture Organisation of the United Nations has classified 25 per cent of the world's fish stocks as depleted, meaning populations are below a level that produces a maximum sustained yield.
The situation is similar in the US, where NOAA Fisheries has assessed 41 of 181 fisheries - 23 per cent - as overfished, including the New England cod fishery and some West Coast groundfish. Both fisheries were managed with an overall harvest, which fishermen competed to get their share of, but saw economic pain when fish numbers plummeted.
Only a handful of US fisheries are managed so that fishermen own a share of the overall harvest, said Hilborn. Among them are Pacific halibut, Alaskan crab, and East Coast clams.
Since the West Coast groundfish fleet was cut in half by an industry-funded buyback, depleted fisheries are rebuilding, and federal fisheries managers are considering the fleet's proposal to adopt individual transferable quotas for more stocks, but the process takes years, says Pete Leipzig, director of the Fishermen's Marketing Association.
The study looked at big eye tuna and yellow fin tuna fisheries off New Zealand, and northern tiger prawn and orange roughy fisheries off Australia, all of which give fishermen individual shares.
The authors plotted revenue and profit against models for fish abundance. Maximum revenues generally came at lower fish populations, but maximum profits came at higher fish populations, and the more overfished the fishery, the greater the profit gains from rebuilding. Profits turned to losses long before the last fish was caught.
Colin Clark, professor emeritus of mathematics at the University of British Columbia and author of the book The Worldwide Crisis in Fisheries, said he had seen similar results to the study's findings among Canadian fisheries managed with individual transferable quotas.
"The good news is a lot of countries are moving toward these ITQ systems and they seem to be the way to go. The bad news is there are really problems in deep sea fisheries [such as tuna] that take place outside anybody's coastal waters. It's like the Wild West with no law whatever."
- AP
