Southern Resident Killer Whales, or orcas, of the Salish Sea region, are beloved creatures for both local residents and tourists. With the creation of Orca Recovery Day — declared by Governor Jay Inslee as October 19, 2019 — more people are becoming aware of this mammals position on the endangered species list.
In fact, the EPA has stated that the Salish Sea orca population has been on a declining trend. Between 1995 and 2003, there were 82 individual orcas, but in 2019 the number has dwindled to a mere 73 — with three orcas mysteriously disappearing in early July, as well.
Hopes of increasing the Southern Resident orca population to 95 by 2020 is now bleak.
Due to the orcas heightened popularity, individuals are left questioning why this animal’s population is progressively depleting. After all, the signature trademark of the Salish Sea is the graceful presence of these black and white, bus sized marine animals.
Is it reduced food supply? Human activity? Or pollution impacting Southern Resident Killer Whales? Interestingly, this trifecta of components can be considered in evaluating the blend of negativity influencing this orca population.
Southern Resident Killer Whales depend upon Chinook salmon — the largest Pacific salmon species — as their primary food source.
Unfortunately, the Chinook salmon population has been steadily declining, as well. According to the EPA, the population has declined 60 percent since the Pacific Salmon Commission began collecting salmon data in 1984.
Not only does this make the orca aesthetically emaciated, but a 2017 study — conducted by University of Washington biology professor Sam Wasser and his colleagues — discovered a connection between low food supply and late-term miscarriage in orcas.
Without proper sustenance, it is possible the orcas are incapable of maintaining the stressors of pregnancy — if they can barely sustain themselves, then it is nearly impossible for female orcas to carry full-term.
While food supply is certainly a contributing factor to Southern Resident orca decline, pollution and human activity — seemingly intertwined — will threaten the orca for generations to come.
“Emerging threats expected to have a big impact going forward are ocean acidification from climate change and continued human population growth in the region,” said Thomas Koontz, professor of Environmental Policy in the School of Interdisciplinary Arts and Sciences.
Whether it be pollution from maritime vessels or surrounding residential areas, the increase of toxic chemicals within the Salish Sea is undoubtedly altering orca habitat.
However, the Southern Resident Orca is not without hope — yet. There are steps we can take to ensure stable or growing numbers, and luckily for us, these actions are within reason.
Simply refusing to fish or eat local Chinook salmon, implementing a rain garden to reduce stormwater runoff, or decreasing the amount of greenhouse gas emitting activities, will propel sustainable progress — all to the benefit of the orca and its ecosystem.
As apex predators, orcas do not have any natural predators besides humans. Unless residents of the Salish Sea region choose to participate in saving this species, we run the risk of saying goodbye to the Southern Resident orca forever.