Source: High North News, No.11, Nov. 1996, published by the High North Alliance

    Sperm Whales Caught by the Tide or Toxins?

    When four sperm whales stranded on the Belgian coast in November 1994, the media reported that they contained high levels of contaminants and that this was most likely the cause of the stranding. In March 1996, as many as 16 sperm whales were found stranded on the beaches of Romo Island off the west coast of Denmark. Investigations carried out have not revealed any significantly high levels of heavy metals or organic toxins, according to veterinary surgeon Bjarne Clausen at Denmark’s National Environmental Research Institute.

    “The whales were probably caught by the tide water”, says Clausen to the High North News. The waters surrounding the Romo Island are very shallow with a large area of the surrounding seabed being exposed at low tide.

    - no definite answer -
    However, the four sperm whales that stranded on the Belgium coast in November 1994 did contain high levels of hazardous chemicals. Contrary to the Danish scientists, Belgian scientists fear that an accumulation of toxic chemicals may be a cause of the stranding, reported Paul Brown of the Guardian News Service in January 1995. Professor Claude Joiris of Brussels University, one of the sources of the Guardian article, says to the High North News that there is no definite answer to explain the stranding. The team coordinated by Prof. Joiris is investigating a series of accidents involving 20-25 strandings, and their basic assumption is that such things do not happen by chance. One of their working hypotheses suggests contamination, as high levels of cadmium, mercury and PCBs have been revealed.

    - toxic waste -
    Prof. Joiris told the Guardian News Service that the “...whales should have been burned as toxic waste to destroy the PCBs that they contained”. But by that time the Belgian authorities had already turned the whales into cattle feed. However, the levels of PCB found in the whales were lower than what Belgian law requires to be burned as toxic waste. Belgian law requires that any substances containing more than 50 ppm (parts per million) PCB, or 50 milligram per kilo is to be burned as toxic waste.

    The values of PCB found in the four sperm whales were 30 ppm PCBs in dry weight in the kidneys, 1-2 ppm in the muscles and 10-20 ppm in the blubber. “The PCB level is always high in sperm whales, so these values were not especially high”, says Prof. Joiris, “but it is not known if and how such high levels of PCB affect the general health of the whales.”

    One of the four whales died at sea. It was very old, perhaps the oldest sperm whale ever observed. The Belgian scientists assume it was the leader of the group, and that the three others remained with the dead body at sea and stranded with the already dead carcass. “Another of these four whales had an infection in the internal ear,” says Joiris, “and such an infection is known to possibly affect orientation.”

    As far as the North East Atlantic baleen minke whale is concerned, the average PCB level in the blubber is about 3 ppm according to a study carried out by Professor Janneche Utne Skaare at the Norwegian State Veterinary Laboratories. This PCB level is not considered to pose any health threat to the minke whale. Pilot whale blubber in the Faroe Islands contains as much as 30 ppm PCB.

    Scientific reports on the strandings will soon be published.

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