Man's increasing taste for warm-blooded marine mammals such as dolphins, porpoises and manatees could lead to the destruction of marine life, according to a new study.

With the growth of the world's population, people in coastal areas are exploring the oceans for food. And because of advances in fishing techniques, these marine mammals are accidentally caught in nets that are meant for fish.

Since 1990, it was reported that at least 87 species of marine mammals have been served in 114 countries. The list includes species such as the pygmy beaked whale, South Asian river dolphin, narwhal, Chilean dolphin, long-finned pilot whale and Burmeister's porpoise. The list also includes well-known species, such as bottlenose dolphins, seals, sea lions, polar bears and three species of manatees.

Some of these species have become delicacies in certain parts of the world, like the manatee's close relative the dugong, making them targets of human consumption. These marine mammals are also being served in countries like Congo, Gabon and Madagascar, as supplementary sources of dietary protein.

In Japan, the SaveJapanDolphins.org. said that despite the low quality of dolphin meat and the high level of mercury it contains, hunters do kill dolphins for their meat and then distribute it to restaurants, grocers and even schools. It also reported that the meat is often mislabeled and sold as whale meat, which is more valuable and nutritious.

The Wildlife Conservation Society is working with fishermen in these areas to reduce the need to catch wild marine mammals, and instead hunt sustainable fish.

According to researchers, there is strict regulation and monitoring when fishing of larger marine mammals, like humpback whales; but the in the case of the smaller warm-blooded marine species, including dolphins and seals, are caught, killed and eaten, it has been largely unstudied and unmonitored.

"International regulatory bodies exist to gauge the status of whale populations and regulate the hunting of these giants," said study researcher Martin Robards, of the Wildlife Conservation Society. "These species, however, represent only a fraction of the world's diversity of marine mammals, many of which are being accidentally netted, trapped, and - in some instances - directly hunted without any means of tracking as to whether these off-takes are sustainable."

Increased awareness of the problem and increased monitoring are needed to prevent the destruction of marine life, the researchers said.

"There is a need for improved monitoring of species such as Atlantic and Indo-Pacific humpback dolphins," said Howard Rosenbaum, director of the Wildlife Conservation Society's Ocean Giants Program.

"In more remote areas and a number of countries, a greater immediate need is to understand the motivations behind the consumption of marine mammals and use these insights to develop solutions to protect these iconic species," he added.