A new study by U.S. and African researchers finds that the decline in fish supplies in the West African nation of Ghana has led to increased illegal hunting of wild game, or bushmeat. The study suggests that marine resources throughout West Africa are near collapse because of overfishing by regional and foreign fleets.

U.S., Ghanaian and South African scientists say that the severe drop in fish along the West African coast has led to the extinction of almost half the species in some animal reserves.

"The fate of nature on land can be intertwined with the management of resources at sea," says Justin Brashares of the College of Natural Resources at the University of California at Berkeley.

He and his colleagues compared 30 years of United Nations records on fish supply with census data on wildlife abundance at six nature reserves in Ghana. Their data published in the journal Science show that years with a lower-than-average supply of fish were the same ones with higher-than-average declines in land wildlife.

Mr. Brashares says this relationship held regardless of other factors such as weather, political cycles, or fuel prices.

"So a poor fish year means fish are too expensive or are unavailable for most people, and these people must turn to wildlife hunting and the sale of wildlife products as a way of securing food and income," he adds.

The researchers found a stunning 76 percent drop in the abundance of 41 species they studied, including buffalo, antelope, big cats, elephants, monkeys, and baboons. Some of the smaller reserves saw local extinctions of nearly half those species, meaning no recorded sightings by park rangers for two years.

Mr. Brashares says part of the cause of overfishing is population growth in West Africa. Another reason is the activity of foreign fishing fleets in the region, according to University of British Columbia fisheries expert Daniel Pauly, who was not involved in this study.

"Basically, the resources are being, plundered?" he notes.

Mr. Pauly says European and Asian nations wrestle generous fishing concessions from West African countries by threatening to withhold economic aid or not to import other products such as peanuts or cotton. Such agreements typically specify that a certain number of foreign boats can have access to African marine resources for a certain time, with no limits to the catch. Furthermore, Mr. Pauly says the fish caught by the foreign fleets do nothing to benefit to local African economy because they are processed elsewhere.

"Most agreements have precluded the fish being landed, processed in the countries [or] the boats being repaired or otherwise provisioned by the African countries," he explains. "Obviously they can't because they don't have the facilities and they don't have the facilities, because they don't develop and they don't develop because these things are not part of the agreements. So it's a vicious circle out of which the countries don't get out."

As a result, Mr. Pauly says West African fishing stocks are in collapse. He notes that the only way these countries can defend themselves against industrial nations' tactics is to form a regional alliance.

"They just don't do it," he says. "There is a sub-regional commission operating in Senegal that is supposed to represent the countries of northwest Africa from Mauritania all the way to Sierra Leone. That commission doesn't have enough money to pay for erasers and pencils, so they cannot do anything."

Justin Brashares and the other scientists who link fish decline to increased wildlife hunting propose the politically and ecologically difficult task of establishing alternative protein supplies in West Africa and increasing the size, number, and protection of regional wildlife preserves.

"Even if we were able to remove foreign fleets from coastal West Africa, we still face the problem of long term management of the fish resource," he notes. "I think what it is going to take is the government of Ghana and the international community working together to increase agricultural productivity and the availability of alternative sources of cheap animal protein such as through livestock intensification and aquaculture and those types of endeavors."

Mr. Brashares says these protective actions might not offer a long-term solution to concerns over West Africa's livelihoods and protein supply, but they are likely to be the most immediate actions for slowing its catastrophic wildlife decline.