‘Jaw-dropping’ levels of heavy metals found in whales
Contamination threatens human food supply
AGADIR, Morocco — American scientists who shot nearly 1,000 sperm whales with tissue-sampling darts discovered stunningly high levels of toxic and heavy metals in the animals that they say could affect the health of ocean life and of the millions of people who eat seafood.
A report yesterday cited high levels of cadmium, aluminum, chromium, lead, silver, mercury, and titanium in the mammals, according to samples taken over five years.
Analysis of cells from the sperm whales showed that pollution is reaching the farthest corners of the oceans, says biologist Roger Payne, founder and president of Ocean Alliance, which conducted the research. The whales travel up to 87,000 miles.
“The entire ocean life is just loaded with a series of contaminants, most of which have been released by human beings,’’ Payne said in an interview at the International Whaling Commission’s annual meeting.
“These contaminants, I think, are threatening the human food supply. They certainly are threatening the whales and the other animals that live in the ocean,’’ he said.
Ultimately, he said, the metals could contaminate fish, which are a primary source of protein for 1 billion people.
“You could make a fairly tight argument to say that it is the single greatest health threat that has ever faced the human species. I suspect this will shorten lives, if it turns out that this is what’s going on,’’ he said.
US Whaling Commissioner Monica Medina informed the 88 member nations of the whaling commission of the report and urged the commission to conduct further research.
“This provides new and very important information about the hazards and the problem of these sorts of contaminants in the ocean, both for the whales and their habitat,’’ Medina told hundreds of government officials, marine scientists, and environmentalists.
Payne, 75, is best known for his 1968 discovery and recordings of songs by humpback whales, and for finding that some whale species can communicate over long distances.
The 93-foot ketch Odyssey set out in March 2000 from San Diego to document the oceans’ health by taking tissue samples from the free-ranging sperm whale, which venture from the poles to the tropics. Like humans, they stand at the top of the marine food chain.
The samples were sent for analysis to marine toxicologist John Wise at the University of Southern Maine. DNA was compared to ensure the animals were not tested more than once.
The original objective of the voyage was to measure chemicals known as persistent organic pollutants, and the study of metals was an afterthought.
The researchers were stunned by the results. “That’s where the shocking, sort of jaw-dropping concentrations exist,’’ Payne said.
Although the crew did not track the movements of the whales, Payne said contamination was embedded in blubber that had been formed in the frigid polar regions, indicating that the animals had ingested the metals far from where they were emitted.
“The biggest surprise was chromium,’’ Payne said. “That’s an absolute shocker. Nobody was even looking for it.’’
Chromium, a corrosion-resistant material, is used in stainless steel, paints, dyes, and the tanning of leather, and can cause lung cancer in people who work in industries where it is commonly used.
Wise applied chromium to healthy whale cells in the laboratory to study its effect. He found that the concentration of chromium found in whales was several times higher than the level required to kill healthy cells in a petri dish, Payne said.