U.S. and Canadian conservationists say a survey found marine mammals like whales, dolphins and manatees are increasingly on the menu in poor countries.

Declines in coastal fish catches have resulted in people in many developing countries seeking other sources of protein and sea mammals are increasingly being tapped as food sources, NewScientist.com reported Friday.

Though the consumption of marine mammals is condemned in much of the world, and large-scale whaling has decreased in the last four decades, smaller cetaceans like dolphins are making up for dwindling protein sources in coastal areas of west Africa, Peru, Brazil, Colombia, Trinidad and Tobago, Madagascar, Sri Lanka, India, the Philippines and Burma, the researchers said.

"This is essentially a bushmeat problem," said Martin Robards of the Wildlife Conservation Society in Alaska, who worked with Randall Reeves of the Okapi Wildlife Associates in Quebec, Canada, to create the first comprehensive survey of the kinds and amounts of marine mammals consumed each year.

From 1970 to 2009 humans ate at least 92 species of cetaceans, they said.

"Traditionally, you think of Japan or natives in the Arctic as big consumers, and they are," Robards said, "but that's not the whole story."