Scientists now have hard data to show European fishing policies are driving some of the bushmeat trade in Africa.
A Ghanian wildlife ranger holds a waterbuck antelope killed by hunters
The market for wild animal meat, which threatens to wipe out a myriad of species, has become a major issue of conservation concern in recent years.
Dr Justin Brashares and colleagues tell Science magazine that consumption of bushmeat in Ghana rises whenever the supply of fish in the country falls.
The region is blighted by overfishing, much of it by EU-subsidised trawlers.
"We took annual estimates of wildlife abundance and compared them with per capita fish supply and found that years of below average fish catches had greater declines of wildlife on land," said Dr Brashares, from the universities of California-Berkeley, US, and Cambridge, UK.
"People in Ghana turned to bushmeat when fish became unavailable."
Brashares' team could also see this link played out in meat markets, where more bushmeat was being traded in years of low fish catches; and on game reserves where poaching increased at times of poor fish supply.
What is more, this link was most obvious in coastal communities.
The possibility that overfishing off West Africa might be having an impact on land biodiversity has been suspected for some time - but this is the first clear evidence to tie the two together.
Other bushmeat research groups working in West African states - such as Senegal, Guinea-Bissau, Liberia and Equatorial Guinea - believe the link probably exists in their areas, too.
Although many of the species taken for bushmeat are often small and abundant creatures (such as rats), significant numbers of rare and endangered animals are also being trapped and shot for food, including the great apes.
"The species we see having declined most drastically [in Ghanaian reserves] include almost the whole suite of large carnivores - the African wild dog, lion, hyena, and leopard," Dr Brashares said.
"Certainly primates are hit hard; things like the black and white colubus monkey; elephant, hippopotamus and bongo antelope are also taken."
West Africa has a large indigenous fishing effort trawling its waters but it is the activities of EU-subsidised and other foreign fleets that have been criticised by conservation groups for accelerating the decline of fish stocks in the region.
The trawlers chase chubb, snappers, mackerel and the highly prized tuna, among others.
The Science study notes that the European Union maintains the largest foreign presence off the coast of West Africa, with EU fish catches increasing 20-fold from 1950 to 2001, and financial subsidies jumping from $6m in 1981 to more than $350m in 2001.
"Other studies have shown that EU subsidies artificially increase the profitability for EU ships to fish in African waters," said Dr Brashares.
The big prize off west Africa is tuna
"If it weren't for this financial support, these studies suggest, it wouldn't be worthwhile for EU fleets to head to west Africa."
Some campaigners have accused foreign interests of pressuring African governments into issuing generous fishing licences by tying negotiations to loans and aid packages.
The EU flatly refutes any suggestion that it operates in this way.
"Under international law, the only stocks we're allowed to fish are those where there's a surplus. The problem lies with unregulated fishing," a European Commission official told BBC News.
"The agreements we make are with national authorities; and in the new generation of agreements, money has to be spent on promoting conservation of resources and sustainable development. We deny that we put any pressure on African states."
Even if the EU was to reform its policy in the region, scientists say, the bushmeat trade would continue. Its drivers are many and complex, they believe.
Poor harvests, war and economic turmoil can all force impoverished communities to turn to wild animals for a source of protein.
Noelle Kumpel, of the Zoological Society of London, who has studied the bushmeat trade in Equatorial Guinea, says the absence of a developed domestic livestock industry delivering fresh produce to markets is a major problem.
"It's not a magic wand solution, but one possibility would be to introduce some small-scale animal husbandry projects to produce livestock that would fill the gap from less bushmeat being available in the market," she told BBC News.
"The answer is not to stop hunting altogether but to minimise the number of people hunting - local people in villages - and to limit the trade to species that are sustainable."
Cambridge University's Dr William Adams, who has reviewed different approaches to conservation, commented: "The clear thing to me is that there is no effective solution to the challenge of maintaining global biological diversity that doesn't engage effectively with the challenge of reducing poverty."