Killer Threats to Killer Whales
Recent news of killer whales sinking boats may bring to mind Jaws or Moby Dick. But before we decide that orcas are sadistic jerks out for personal revenge, consider another possible explanation. The behavior could be symptomatic of environmental stresses, like loss of prey, that orcas are experiencing around the world. The orcas also might just be playing around. We all should learn more about this charismatic megafauna. After all, the interests and activities of humans and orcas are more closely interrelated than most people realize.
Members of the dolphin family, orcas are also called killer whales because they are an apex predator. Like dolphins and whales, they communicate through vocalization. And like many land mammals, they live in extended matriarchal family groups. These pods hunt together, much like wolves and other land-based pack animals. They avoid competition with other pods by maintaining large territories, even specializing in different types of prey. Overall, orcas are generalists, hunting a wide variety of species from salmon to seabirds and even sharks and whales.
Clans are groups of pods that share a dialect, or similar vocalizations. Orca communities, or ecotypes, are defined by association patterns and can include multiple clans. There are 11 different types of orcas, distributed across every ocean in the world. Before the Iberian yacht sinkings stole the spotlight, the resident communities of the Pacific Ocean were the most famous orcas. These include the Northern Residents of British Columbia with more than 300 members, and the endangered Southern Residents with fewer than 75 individuals left.
In the U.S., the Marine Mammal Protection Act protects all orcas. The Southern Resident ecotype is also listed as endangered under the federal Endangered Species Act. Since listing in 2005, this population has continued to decline, with nearly 70% of pregnancies ending in failure – a statistic that fluctuates with the availability of Chinook salmon. This population relies on Chinook salmon for nearly 80% of its diet.
Other orca ecotypes are not such picky eaters, but they all face a variety of threats. Like most marine species, orcas can become bycatch caught in plastic pollution from abandoned fishing gear, which can lead to stress, starvation, and even death. Other pollutants, including sewage, pesticide runoff, and oil spills also harm orcas. Noise pollution from ocean vessels can impede orca’s ability to hunt. Orcas can be injured in collisions with boats. One theory for the origin of the alleged vendetta in the Mediterranean is trauma from a boat strike.
Orcas in the Strait of Gibraltar have been known to steal tuna right off of fishermen’s lines. But framing orca survival as directly competing with human economies – and dinners – is misguided. While food shortages do threaten orca survival, especially for the Southern Resident population, the idea of competing with orcas for fish detracts from the central environmental issue of maintaining healthy fish stocks.
With Copper River king salmon costing as much as $70/pound in 2023, salmon conservation is almost as critical to humans as it is to the orca. Certain populations of sockeye salmon, coho salmon, chinook salmon (also called king salmon), and Atlantic salmon are listed as endangered.
In May, a Washington state judge issued an order in a controversial lawsuit to shut down trolling for king salmon in Southeast Alaska this summer to protect food sources for the endangered Southern Residents. The ruling, which has since been blocked, would have undoubtedly hurt the bottom line for Alaska fishing, and by extension, public funds in the state. What is less certain is how much such measures would have benefitted the salmon and the orca that depend on them. Troll fishing is generally considered one of the more sustainable fishing methods, but if spring salmon runs are any indication, drastic measures may indeed be called for.
Recreational fishing has been suspended in Washington watersheds this year to protect chinook returning to spawn. In a generational echo from a disastrous 2015 spawning season, their numbers are at a record-breaking low.
Fishing pressure undoubtedly contributes to the decline of wild salmon. But degraded and inaccessible spawning habitat is equally important. Many conservationists point to dams, especially those along the Snake River as the primary culprit behind the decline of salmon and other anadromous fish. Dam removal and the addition of fish ladders have proven to be successful in restoring once-extinct salmon populations. But these strategies can conflict with competing values: renewable electricity and the West’s water crisis.
Coastal habitat protection is important for orcas as well. Since 2019, temporary restrictions have required watercraft to maintain a 300-yard distance from orcas in coastal waters. This year, Washington state supplemented this federal restriction with its own law that requires boats to keep 1,000 yards from southern resident orcas. However, craft in Canadian waters will not be subject to the law, and a Port of Vancouver expansion is likely to impact Fraser River sockeye populations.
While battles overfishing regulations play out in the courts, individuals can support nonprofit organizations like the Whale and Dolphin Conservation, Wild Salmon Center, and local habitat conservation efforts. When visiting the coast, engage in responsible whale watching. And choose more sustainable seafood at restaurants and the grocery store; consider arctic char or steelhead trout as alternatives to salmon.