The Southern Resident Orcas, on the Road to Extinction
In August 2018 the world was watching Tahlequah (J35), a Southern Resident orca, as she carried her dead calf around for 17 days for over 1000 miles. The images of the grieving mother brought sadness to the people who care about these giants, but also helped to raise awareness around the situation these animals are facing. Extinction.
Three distinct groups of orcas can be found in Canadian Pacific waters. These groups are the Transient (or Bigg’s), Offshore and Resident Orcas. Even though these groups roam in the same waters, they are socially and genetically isolated from one another, which means that they do not interact nor interbreed. Resident Orcas, which are divided between the Southern Resident and the Northern Resident populations, do not interbreed either. This can seem problematic for the declining Southern Resident orca population. Indeed, unlike the Northern Resident population, the Southern Resident orcas are facing substantial threats, adding them to the list of endangered species since 2001 in Canada and 2005 in the United States. So what is happening to these whales?
Let’s take a closer look at the 74 remaining Southern Resident killer whales. The orcas are divided in three pods: The J pod, the K pod, and the L pod. Orcas are highly social animals and each pod is a distinct family group, or matriline, led by the oldest female family member. Both male and female orcas stay with their natal group for life! The J, K and L pods join together at times, creating large groups called super pods. Unfortunately, it was announced on August 6, 2019 that Princess Angeline (J17), the J pod’s matriarch named after the daughter of Chief Seattle, had died this summer, along with two others. This was devastating news for the J pod that lost their leader and guide. Tahlequah, Princess Angeline’s oldest daughter and the orca that carried her dead calf on a tour of grief, is now likely to become the new matriarch. However, Tahlequah is only 21 years old, which is considered to be very young for such an important role.
Why are the orcas dying?
The Southern Resident orcas were traditionally found near or in the Salish sea, but now their range extends from southeastern Alaska to central California. In the 1990s there were about a hundred of them. However, their number has been decreasing ever since, leaving the population at only 74 today. Reduced availability of the threatened and endangered Chinook salmon, the orcas’ preferred pray, appears to be at the core of the population decline, along with increased exposure to pollutants, and pressure from vessel disturbance.
Orcas and the Chinook salmon
Unlike other salmon species, the Chinook is known to be available on a year-round basis around the mouth of the Columbia river and the Fraser river. The spring salmon runs down the Columbia and the above Snake river are particularly important, allowing the ocean giants to stock up during the summer, prior to the leaner winter months. However, the wild Chinook is now one of the least abundant species of salmon in this area and is also listed under the Endangered Species Act in the United States. The fact that Chinook populations remain in the nearshore waters during the ocean phase of their life cycle makes them more vulnerable to water contaminants. In Washington, hatchery fish now account for about 75% of all harvested Chinook. This may explain why the orcas’ range has changed and why the whales have appeared in northern California and southeastern Alaska. Their presence in these areas was associated with large returns of Chinook Salmon, which they had to seek out because of less abundant prey within their traditional range. This, in turn, puts the orcas at greater risk as they are forced to travel greater distances to forage their food and therefore leads to lower reproductive rates and higher mortality rates.
Scientists and conservationists view the dams blocking the spring runs down the Columbia and Snake rivers as the major obstruction to feeding, and thus conserving, the orca population. There are in fact eight dams standing between the juvenile salmons’ place of origin and the Pacific Ocean. Several coalitions of scientists, Indigenous peoples, community groups and lawyers are fighting for the breach of the four federal dams on the Lower Snake river. In fact, it is estimated that removing these dams would bring “1 million to 2 million additional adult Chinook into orca territory annually and revitalize 8,850 kilometers (5,500 miles) of tributaries for salmon spawning”(1). The reality is, economics seem to be more important than the orcas’ right to life in Washington… Breaching the dams would simply be too expensive and time consuming. Meanwhile, orcas like Princess Angeline (J17) or Scoter (K25) and newborn calves are dying of starvation.
Aerial images of adult male Southern Resident killer whale K25, taken in September 2016 (left) and September 2018, the recent image shows him in poorer condition with a noticeably thinner body profile. (NOAA Fisheries)
Aerial images of J17, from September 2015 to May 2019. The latest images show she is emaciated with signs of "peanut head" because of a drastic loss of fat. (Holly Fearnbach and John Durban/NOAA Fisheries)
Sounds and pollution
Southern Resident orcas use echolocation to locate their prey, which means they locate fish by using reflected sound. This is also how the whales communicate with each other. Traffic of both private and commercial vessels has increased dramatically in recent years, which forces the orcas to navigate in busier and louder waters. Moreover, industrial activities such as dredging, drilling, construction, seismic testing and military sonar, and other vessel use of low and mid-frequency sonars also impact the acoustic environment. The constant disturbance is disrupting communication, reducing the distance over which social groups can detect each other and masking echolocation, which terribly affect the orcas. If the orcas cannot locate their already scarce prey, the animals are bound to starve. Coastal Salish tribes on both sides of the US-Canada border fear that the construction of Canada’s Trans Mountain Pipeline will worsen the current situation as it will triple oil tanker traffic through the Salish Sea, imperiling the already endangered orcas and increasing the risk of a major oil spill.
Oil spills are not the only pollution threat, however. There are thousands of chemicals to be found in the sea the orcas call home.
Michelle Bender, who is the ocean rights manager at the Earth Law Center, was right in saying that “our existing environmental laws … designed to protect the Southern Residents have failed them. Orcas do not actually have a right to not go extinct”.
There is still hope left for Tahlequah’s family, but if something isn’t done right now to help the dying ocean giants, the Southern Resident orcas will only exist in stories told by local Indigenous nations.
About the Author
Kimberley has a M.Sc in International Studies (Cooperation, Development, Economics) from the University of Montreal. She is passionate about the environment and Indigenous peoples' land rights. Instagram - @kimberleymgs