The largest members of the dolphin family, orcas, also known as killer whales, are perhaps the most recognizable cetacean, with their distinctive black and white markings. These small, toothed whales inhabit temperate to cooler waters throughout the world. Today, most people know of this popular whale but many are probably unaware of the multiple perils confronting the mammals, especially those in the US Pacific Northwest. There are three subspecies of these orcas: resident, transient and offshore, with different social structures, language and prey. Although their ranges overlap, they do so without aggression or intermingling among the groups.
Little is known about offshore orcas except that they can travel in groups of 30 to 60 individuals, and sometimes more. Transient orcas live in smaller groups, often of just five to seven animals, preying on smaller marine mammals such as seals, otters and sea lions. Resident orcas form the largest groups, or pods, which can number several dozen animals. They can even form associations of several coexisting pods. Sightings of the Pacific Northwest resident orcas occur more often than the other ecotypes because although they can roam up to 800 miles, or as far as California, they consistently return to the same areas. These orcas follow their food, and for the Southern Residents, Chinook salmon constitutes a main ingredient of their diet.
Unfortunately the salmon are disappearing. According to the Save Our Wild Salmon coalition, every winter the Southern Resident whales move out to the northeastern Pacific Ocean from Washington State’s San Juan Islands and while traveling, feed on Chinook salmon from the Columbia River. Like all anadromous fish, Chinook salmon spend most of their adulthood at sea, migrating to the rivers to spawn. Once teeming with salmon and considered the premiere salmon-bearing river system across the globe, the Columbia-Snake River Basin’s salmon numbers have plummeted over the past century to less than 1 percent of their former tens of millions. This decline is largely due to dam construction and habitat loss, with 13 species of anadromous fish listed under the Endangered Species Act (ESA).
The endangered status of salmon threaten the survival of the orcas, with local whale scientists much alarmed and up in arms. Ken Balcomb, Executive Director and Principal Investigator of the Center for Whale Research in Friday Harbor, Wash., and other scientists recently wrote to the Secretary of Commerce and Director of the National Oceanic and Atmospheric Administration, stating “[A]s federal scientists have previously recognized, and 300 independent scientists have echoed, removing the lower Snake dams is ‘the surest means’ to recovering at least four endangered salmon runs (two of which are Chinook), and will provide critical ancillary benefits, such as cooler water temperatures, to endangered non-Snake River salmon. Lower Snake dam removal would restore salmon abundance to 1.5 million acres of high elevation, low temperature, largely undeveloped, mostly protected lands. When coupled with sound harvest policies, appropriate land use, and hatchery/aquaculture reform, opening access to this inland habitat would allow Chinook numbers to increase to levels that would again sustain Southern Resident [whales], particularly during crucial winter months when they leave Puget Sound.”
The Pacific Northwest salmon populations also suffer from toxic pollutant poisoning which in turn affects the Southern Resident orcas. A study published in a 2009 issue of Environmental and Toxicology Journal found the orcas are consuming salmon that have remarkably high concentrations of persistent organic pollutants, including polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT). Peter Ross, a scientist with the Canadian Department of Fisheries and Oceans, has said of the resident orcas “[T]hese are some of the most PCB-contaminated mammals on the planet.”
The manufacture and use of the pesticide DDT, and the manufacture and most uses of PCBs have been banned for decades. However these bio-accumulating toxins persist in the environment. Southern Resident orcas have been found to be nearly four times as contaminated with PCBs as the northern population. Researchers have found that the southernmost salmon had both the highest concentrations of chemicals and the lowest amount of body fat which results in the orcas having to eat far more of the contaminated fish to meet their energy needs, thus concentrating the toxins. The impacts of consuming contaminated fish are exacerbated on malnourished animals and the decline in salmon numbers is already affecting the Southern Resident orcas. In the summer of 2008, seven members of the Southern Resident population went missing, with some appearing malnourished when last seen. None have been seen since and all are now presumed dead.
The Southern Residents have always had it tough. During the late 1800s and early 1900s they were seen as competition for fish, which prompted deadly shootings by anxious fisherman. Later, in the 1960s through mid 1970s the unlucky whales fell victim to the captive aquarium industry. Cruel round-ups resulted in at least 13 deaths and 45 whales—almost half the population—shipped to marine parks. The sole survivor of this round-up, Lolita, remains languishing at Miami’s Seaquarium.
Today the orcas of the Pacific Northwest, and their cousins throughout the world’s oceans, face additional challenges that could not have been imagined a century ago. Noise pollution, active sonar, shipping traffic and oil spills are all impacting them, in some cases resulting in their deaths. The US Navy for example already uses part of the Southern Resident orcas’ habitat as an active sonar training range and even intends expanding its operations there.
Fortunately these ill-fated orcas have many friends. In 2005, in response to aggressive petitioning by concerned groups and scientists, the population—then numbering 89 individuals—was listed under both the ESA and Canada’s Species at Risk Act. With the ESA listing came a requirement for the creation of a recovery plan to address issues such as oil spills, pollution, salmon recovery and guidelines for boating in the vicinity of whales. In July of 2009, the National Marine Fisheries Service proposed regulations under the ESA and Marine Mammal Protection Act for boating. The regulations will, among other things, prohibit vessels from approaching orcas in the Northwest US region within 200 yards; parking in the path of whales for vessels in inland waters of Washington State; and entering a conservation area during a defined season.
There’s hope for these born survivors, but with so few remaining, hope for their survival must turn into action to ensure it.