The Chernobyl disaster created a large poisoned involuntary park. Similarly, mercury pollution (as well as other persistent organic pollutants) may perversely help wildlife conservation by reducing hunting (but damaging the health and livelihoods of those who depend upon the hunting of animals they have little to do with poisoning). The New York Times writes about how Mercury Taint Divides a Japanese Whaling Town:

For years, Western activists have traveled to this remote port to protest the annual dolphin drive. And for years, local fishermen have ignored them, herding the animals into a small cove and slashing them until the tide flows red. But now, a new menace may succeed where the activists have failed: mercury.

…Dolphin meat is a local delicacy, served raw as sashimi or boiled with soy sauce. People here are used to the international scorn that accompanies the dolphin hunt and have closed ranks in the face of rising outrage — until now.Last June, laboratory tests showed high levels of mercury in dolphin and pilot whale, a small whale that resembles a dolphin, that were caught and sold here. Schools stopped serving pilot whale meat for lunch, and some local markets removed it as well as dolphin from their shelves.

The scare has divided the community. Most local officials and the fishermen’s union insist that the mercury danger is overblown, while some others have begun to question a tradition.

…When eaten by humans over a long period, mercury can cause birth defects, brain damage and death. The world’s worst case of mercury poisoning occurred in Japan in the 1950s, when thousands were killed, sickened or crippled in the city of Minamata because of mercury dumped into the sea as industrial waste.

Professor Endo participated in the studies that first brought mercury risks in dolphin to light. Since 2000, he has tested hundreds of samples of dolphin and whale meat throughout the country. In dolphin and pilot whale, he said he has typically found mercury levels ranging from 10 to 100 parts a million, far above the Japanese government’s advisory level of 0.4 part a million.

The most heavily contaminated sample he has ever found, he said, was from the internal organs of a pilot whale sold in a Taiji supermarket, which had 2,000 parts a million.

Despite the public awareness of mercury poisoning in Japan because of the Minamata disaster, the health and agriculture ministries have done little to inform people about mercury levels in whale and dolphin meat, Professor Endo and other biologists say. While the health ministry has conducted surveys of dolphins and pilot whales that show levels of 10 to 50 times the advisory level, the only warning it has issued is for pregnant women.