AGADIR, Morocco — Sperm whales feeding even in the most remote reaches of Earth's oceans have built up stunningly high levels of toxic and heavy metals, according to American scientists who say the findings spell danger not only for marine life but for the millions of humans who depend on seafood.
A report released Thursday noted high levels of cadmium, aluminum, chromium, lead, silver, mercury and titanium in tissue samples taken by dart gun from nearly 1,000 whales over five years. From polar areas to equatorial waters, the whales ingested pollutants that may have been produced by humans thousands of miles away, the researchers said.
"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," said biologist Roger Payne, founder and president of Ocean Alliance, the research and conservation group that produced the report.
The researchers found mercury as high as 16 parts per million in the whales. Fish high in mercury such as shark and swordfish -- the types health experts warn children and pregnant women to avoid -- typically have levels of about 1 part per million.
The whales studied averaged 2.4 parts of mercury per million, but the report's authors said their internal organs probably had much higher levels than the skin samples contained.