"These agreements are extremely unfair," said Daniel Pauly, director of the Fisheries Centre at the University of British Columbia, Canada. "If you have a very powerful economy negotiating with a weak one, then it's very difficult for the weak ones to say no."
Pauly, who isn't connected with the new study, adds that foreign vessels are often granted access to fishing grounds with no limits on catch.
- Eastern Lowland Gorilla Numbers Plunge to 5,000, Study Says
- Photographer Fights African Poaching With Grisly Pictures
- "Bush Meat" Crisis Needs Urgent Action, Group Warns
- Militia OK'd to Shoot Poachers in Africa
- Poachers Threaten Last Wild Northern White Rhinos
- Corruption Top Threat to African Animals, Study Says
"It's as if someone gave you three shopping carts for a day at a supermarket and told you that you wouldn't need to go through the cashier," he said.
Tuna are among the main fish species targeted by foreign vessels, Brashares said, with Ghana just one of many West African countries now subject to heavy fishing pressure.
For instance, the number of authorized French and Spanish tuna boats operating off the country of Guinea-Bissau jumped 300 percent from 1994 to 1998. That's an estimated catch increase of 33,000 tons per year, according to fisheries scientists at the University of Washington in Seattle.
Likewise, Brashares says, evidence from Cameroon, Congo, Gabon, and Liberia suggests "strong negative correlations between fish supply and bush-meat consumption." He added, "This is not only a Ghana issue, or a West Africa issue but an issue for much of Africa and perhaps the developing world."
Ghana's markets traditionally sell everything from shark and snapper to sardinella and anchovy. Brashares says these smaller, open-ocean species are particularly important sources of protein for poorer communities, as they can be dried and transported to remote inland regions.
The researchers say reforming EU policy won't completely resolve the problem of depleted stocks, partly because other nations also fish off West Africa. But they say it's a solution that can be enacted quickly.
Study co-author Andrew Balmford, senior lecturer in conservation biology at Cambridge University in England, added, "Given the EU's expressed concerns about the bush-meat trade, phasing out subsidies to their own fleets offers at least a short-term route to limit the trade, while simultaneously enhancing local fishers' livelihoods."
In the longer term the study highlights the need to provide alternative sources of protein such as cattle.
Brashares added, "Livestock production is increasing rapidly but it just isn't anywhere near the point where it can replace fish and bush meat. The limited availability and high costs associated with livestock production make domestic meat too expensive for most Ghanaians."
James Owen is a freelance science and nature journalist based in London.
Don't Miss a Discovery
Sign up for the free Inside National Geographic newsletter. Every two weeks we'll send you our top news stories by e-mail.
For more bushmeat stories, scroll to bottom.
SOURCES AND RELATED WEB SITES