Killer Whale - Conservation

Conservation

In 2008, the IUCN changed its assessment of the killer whale's conservation status from conservation dependent to data deficient, recognizing that one or more killer whale types may actually be separate, endangered species. Depletion of prey species, pollution, large-scale oil spills, and habitat disturbance caused by noise and conflicts with boats are currently the most significant worldwide threats.

Like other animals at the highest trophic levels, the killer whale is particularly at risk of poisoning from accumulation of toxins, including polychlorinated biphenyls (PCBs). European harbour seals have problems in reproductive and immune functions associated with high levels of PCBs and related contaminants, and a survey off the Washington coast found PCB levels in killer whales were higher than levels that had caused health problems in harbour seals. Blubber samples in the Norwegian Arctic show higher levels of PCBs, pesticides and brominated flame-retardants than in polar bears. When food is scarce, killer whales metabolize blubber for energy, which increases pollutant concentrations.

In the Pacific Northwest, wild salmon stocks, a main resident food source, have declined dramatically in recent years. On the west coast of Alaska and the Aleutian Islands, seal and sea lion populations have also substantially declined.

In 2005, the United States government listed the southern resident community as an endangered population under the Endangered Species Act. This community comprises three pods which live mostly in the Georgia and Haro Straits and Puget Sound in British Columbia and Washington. They do not breed outside of their community, which was once estimated at around 200 animals and later shrank to around 90. In October 2008, the annual survey revealed seven were missing and presumed dead, reducing the count to 83. This is potentially the largest decline in the population in the past ten years. These deaths can be attributed to declines in Chinook salmon.

Scientist Ken Balcomb has extensively studied killer whales since 1976; he is the research biologist responsible for discovering U.S Navy sonar may harm killer whales. He studied killer whales from the Center for Whale Research, located in Friday Harbor, Washington. He was also able to study killer whales from "his home porch perched above Puget Sound, where the animals hunt and play in summer months." In May 2003, Balcomb (along with other whale watchers near the Puget Sound coastline) noticed uncharacteristic behavior displayed by the killer whales. The whales seemed "agitated and were moving haphazardly, attempting to lift their heads free of the water" to escape the sound of the sonars. "Balcomb confirmed at the time that strange underwater pinging noises detected with underwater microphones were sonar. The sound originated from a U.S. Navy frigate 12 miles (19 kilometers) distant, Balcomb said." The impact of sonar waves on killer whales is potentially life-threatening. Three years prior to Balcomb's discovery, research in the Bahamas showed 14 beaked whales washed up on the shore. These whales were beached on the exact day U.S Navy destroyers were activated into sonar exercise. Of the 14 whales beached, six of them died. These six dead whales were studied, and CAT scans of the two of the whale heads showed hemorrhaging around the brain and the ears, which is consistent with decompression sickness.

Another conservation concern was made public in September 2008 when Ottawa decided it was not necessary to enforce further protections (including the Species at Risk Act in place to protect endangered animals along their habitats) for killer whales aside from the laws already in place. In response to this decision, six environmental groups sued the federal government in Vancouver, Canada, claiming killer whales were facing many threats on the British Columbia Coast and the federal government did nothing to protect them from these threats. A legal and scientific nonprofit organization, Ecojustice, led the lawsuit and represented the David Suzuki Foundation, Environmental Defence, Greenpeace Canada, International Fund for Animal Welfare, the Raincoast Conservation Foundation, and the Wilderness Committee. Many scientists involved in this lawsuit, including Bill Wareham, a marine scientist with the David Suzuki Foundation, noted increased boat traffic, water toxic wastes, and low salmon population as major threats, putting approximately 87 killer whales on the British Columbia Coast in danger.

Noise from shipping, drilling, and other human activities is a significant concern in some key killer whale habitats, including Johnstone Strait and Haro Strait. In the mid-1990s, loud underwater noises from salmon farms were used to deter seals. Killer whales also avoided the surrounding waters. High-intensity sonar used by the Navy disturbs killer whales along with other marine mammals. Killer whales are popular with whale watchers, which may stress the whales and alter their behavior, particularly if boats approach too closely or block their lines of travel.

The Exxon Valdez oil spill adversely affected killer whales in Prince William Sound and Alaska's Kenai Fjords region. Eleven members (about half) of one resident pod disappeared in the following year. The spill damaged salmon and other prey populations, which in turn damaged local killer whales. By 2009, scientists estimated the AT1 transient population (considered part of a larger population of 346 transients), numbered only seven individuals and had not reproduced since the spill. This population is expected to die out.