While whaling experts and negotiators debate the future of whaling, some specialists worry that whale health and the safety of whale meat are not getting enough attention.
“Marine animals such as whales and dolphins have far higher levels of pollutants,” said Shinsuke Tanabe, a professor of environmental chemistry and ecotoxicology at Ehime University’s Center for Marine Environmental Studies.
Sitting at the top of the food chain, whales and other sea mammals are magnets for pollutants, which tend to accumulate at the higher end of the predatory ladder, the marine pollution expert said.
“What is strange is that even though they are very far from land-based pollution sources and in a relatively clean ocean, they are much more prone to contamination than land animals or people,” he said.
Tanabe solved this mystery in 1988, when he reported that whales and other marine mammals lack the enzymes found in land animals that break down poisons.
Experts attribute this to evolution. While land animals developed the means to break down poisons produced by terrestrial plants, marine life evolved largely devoid of this challenge, he said. Consequently, marine mammals are veritable repositories for various toxins.
Consumer groups have voiced concern over high levels of pollutants, such as heavy metals and polychlorinated biphenyls in whales, while meat from sperm whales caught in the North Pacific last season was not put on the market due to excessive mercury levels.
A group of experts, working at the behest of the Health, Labor and Welfare Ministry is looking into current food standards and whale meat contamination levels. They are due to come up with recommendations this summer.
Current standards for mercury and PCBs are believed to be inadequate, as they are three decades old and do not address the problem of chronic toxicity, or long-term exposure, Tanabe said.
But while there is still a risk, whale is generally consumed so rarely today that Tanabe is not worried about its toxic effects on people.
“When I was a child, whale meat often appeared in school lunches — sometimes two or three times per week,” the 51-year-old researcher recalled.
Still, the government should warn high-risk groups, such as breast-feeding mothers, pregnant women and people in fishing hamlets who might regularly consume the internal organs of whales.
“I eat whale meat. I like it and I am done reproducing, but I wouldn’t let my children eat it,” Tanabe said.
Labels explaining whether meat is dolphin or whale, where it was killed and whether it was a toothed or baleen whale would help consumers to make informed choices, he said. Coastal and toothed cetaceans tend to have much higher contamination levels.
However, it is the health of marine mammals that concerns Tanabe most.
“Rather than people, it is dolphins and whales that we need to be worried about. They are very threatened by these chemicals,” he said.
“We need to think more about the health of whales. Right now everything is so human-centered.”
The well-being of cetaceans is often lost in squabbles over whaling or the implications of marine pollution for people.
“This way of thinking needs adjusting,” he said.
The number of mass strandings — when hundreds or thousands of cetaceans beach themselves — has jumped this century, and Tanabe points out that pollution could be one cause.
He explains that pollutants can impair immune functions, making animals susceptible to viral infections.
Dangerous chemicals stored in fat, such as DDT or PCBs, are passed on to offspring through the fat in mothers’ milk, he said. While fat comprises just 2 percent to 3 percent of milk in humans, in whales it is 10 times that amount.
“Current safety criteria are based on data for humans and this could lead to the demise of species that are more sensitive to chemicals,” he said.
Dolphins and whales also develop cancer, but research on what environmental toxins lead to which diseases in cetaceans is next to nil, Tanabe said.
“I think Japan needs to take a leadership role from a research perspective,” Tanabe said, adding that he would like to see an ambitious program to sequence cetacean DNA to better understand and protect the creatures.
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