In March 2000, a 22-year-old killer whale washed ashore just north
of Bellingham, Washington. In what should have been the prime of its
life, the whale, known as J-18, was emaciated, its reproductive organs underdeveloped. A normally harmless bacterial infection in an abscess on its stomach had finally killed it.
The whale’s compromised immune system was the result of contamination by polychlorinated biphenyls, or PCBs, according to Dr. Peter Ross, a research scientist at the Institute of Ocean Sciences in Victoria, British Columbia. As he reported in the June 2000 issue of Marine Pollution Bulletin, Puget Sound killer whales are the most PCB-laden marine mammals on the planet. Although no research has been conducted to determine the effect of high levels of PCBs on killer whales, Ross’s studies have shown immune system dysfunction in harbor seals at levels as low as 17 parts per million. In 1994, when researchers last tested J-18, they discovered 63 parts per million of PCBs in its blubber. At the time of its death, says Ross, it was useless to test for PCBs
because the wasted whale had metabolized much of its body fat, where the PCBs are stored, and thus likely much of the contaminant.
PCBs came into widespread use in the 1930s. The stable oily liquid, which absorbs intense heat, was used as a coolant for electrical transformers and capacitors. It was also incorporated into a broad range of industrial products, including lubricants, insecticides, paints, and varnishes. By the time the compound was found to be toxic, it was being used and produced around the world.
The fight against PCBs was an early success story for the modern environmental movement, which managed to get the chemical banned in the United States in 1976. Worldwide, almost no PCBs have been made since 1989. But ceasing production is not enough to repair the damage caused by this sturdy, enduring compound.
Killer whales accumulate great quantities of PCBs because their primary food sources--salmon and, in some cases, seals--are high on the food chain and long-lived. The high levels of PCBs that build up in the prey are passed along to the whale. The whales have large fat reserves where PCBs can be stored, and since killer whales can live as long as 80 years, the toxic levels keep growing over a lifetime.
Richard Osborne, science curator of the Whale Museum in Friday Harbor, says that declining salmon runs may be contributing to the problem. Puget Sound whales are traveling farther and farther in search of food every year. Last winter a killer whale that usually resides in the southern part of the sound was spotted in Monterey Bay, California, something unheard of in past years, Osborne says. Ross and other researchers say whales that are exerting themselves because they are short on food will metabolize fat reserves along with the PCBs stored there, pushing more of the poison into their bloodstreams. “My gut reaction is that a lack of food may exacerbate problems,” Ross says.
Ross studied three Puget Sound whale populations: residents that stay in northern and southern parts of the sound and transients that move in and out of the area. The northern residents’ PCB-contamination level--37 parts per million--ranked them high on the most-polluted marine mammals list. But, Ross says, that was hardly the shocker. Among the southern residents, he found contamination levels far higher, 146 parts per million on average. The numbers for the transients were higher yet.
“These whales are telling us something about the degree of local contamination [in Puget Sound],” says Ross. Hot spots of PCB pollution have been recorded in parts of the sound that border urban and industrial areas, including Elliot Bay, Commencement Bay, and the Sinclair Inlet. As for the transient whales, they may be suffering because of an even more intractable problem: global atmospheric PCB contamination. Donald Mackay, a professor at Trent University in Peterborough, Ontario, and director of the Canadian Environmental Modeling Center, explains that when the compound escapes into the environment it can remain toxic for many decades. “There are PCBs everywhere,” says Mackay.
One widely used method of PCB disposal, incineration, releases PCBs into the atmosphere, where they are then easily spread. The compound has been found from isolated Rocky Mountain lakes to remote areas in the Arctic. High levels of PCBs have even been found in the eggs and tissue of the black-footed
albatross on the isolated Midway Atoll in the South Pacific.
Activists are now working to get Puget Sound killer whales listed as endangered under the U.S. Endangered Species Act. The Washington State Department of Ecology is developing a program to reduce the release of persistent organic pollutants like PCBs, and 122 nations are now engaged in ratifying a treaty that would not only work to phase out the production of these toxic chemicals, but also set up guidelines for their proper disposal. For a poison like PCBs, proper disposal is a vital step toward ensuring the health of Puget Sound’s majestic residents.