Southern Resident Killer Whale History
Through fossils and DNA analysis, scientists have determined that orca whales (actually a species of oceanic dolphins) evolved about 5 million years ago. The three pods of the Southern Resident killer whale population comprise a large extended family, and have not interbred with other pods for about 700,000 years. These highly social, matrilineal whales are taught and influenced primarily by their grandmothers and great-grandmothers and remain with their mothers for life. The Southern Resident’s J, K and L pods each have distinct characteristics including dialects and preferred home ranges. Each pod contains several family units, each descended from a single female ancestor. These units, called matrilines, are usually composed of an adult matriarch and her offspring.
Fossil records indicate the Southern Resident killer whales (also known as SRKW, Southern Resident orca, Southern Residents) have frequented Salish Sea waters for thousands of years, living in harmony with Pacific Northwest native peoples. Known locally as “blackfish,” these whales were never hunted for food and harming an orca is still considered taboo. Many tribes believe their deceased relatives return as orca whales. They are viewed as close kin and ancestors, as well as spiritual totems.
The Southern Resident orca eat fish exclusively (unlike other killer whale types) and over 80% of their diet consists of Chinook, also known as King, salmon. It is estimated that an adult whale must consume about 18-25 Chinook a day to sustain themselves. A century ago, Chinook were so large, an orca might need to eat only three a day. The whales spend most of their time traveling (up to 100 miles a day), foraging, socializing and resting. Orca whales must remain conscious in order to breathe so when they sleep, only half of the brain’s hemisphere sleeps at a time while the other half remains awake and conscious. This is known as unihemispheric sleep and is common to dolphins and some species of whales.
Prior to the twentieth century the Southern Resident population is estimated to have numbered at least 200 whales, perhaps many more, as the first population census was not conducted until 1973. During the early days of colonization and up through the 1960s, fisherman considered killer whales rivals and often shot them on sight. In 1960, representatives of fishing organizations in British Columbia met with officials from the Department of Fisheries to discuss ways to control the orca population. Solutions such as bombing the animals from the air were discussed, and eventually the government decided to install a machine gun on a lookout northwest of Campbell River.
It wasn’t until later in the 1960s that killer whales began to be seen in a new light. Researchers studying dolphins and whales discovered that these creatures were actually highly intelligent, social and capable of complex forms of communications. They were also observed to have close familial bonds. As the public became more enamored of killer whales, live captures for seaquariums began taking place in the Salish Sea. The hardest hit were the Southern Residents, due to their close proximity in local Puget Sound waters. In the space of 12 years, 45 live Southern Resident orca, mostly juveniles, were captured. At least 13 died or were injured during these capture attempts, which used boats, planes and explosives to drive the whales into nets. The frantic distress cries of the terrified orca were heard from miles away as mother’s were separated from their calves. The J pod, in particular, lost nearly half its members. Only one Southern Resident remains alive in captivity, Lolita, also known as Tokitae, a member of the L pod. She has spent nearly 50 years living in a small concrete tank, performing tricks for Miami Seaquarium customers. Tokitae still calls in the unique dialect of her pod, and her 83-year old mother is still alive.
Killer whales have the second biggest brains of all ocean mammals. MRI studies of the killer whale brain have shown a similar level of cortical folding to humans and other higher mammals (such as chimpanzees), which indicates high amounts of cognitive processing. Orca brains also show an enlarged limbic lobe. In humans, the limbic system is associated with emotional life and behavior as well as the formation of memories. The cellular architecture of orca whales’ limbic systems, including a large number of spindle cells, indicates a great aptitude for emotional expression. The relative number of spindle cells (associated with processing of social organization and empathy) in killer whales is larger than that of even the human brain, which reveals a deep capacity for emotional expression. Observations of orca whales, both in the wild and in captivity, show that they experience a range of emotions, as well as self-awareness. The images of J-35/Tahlequah, the mother whale who carried her dead baby for weeks on her nose, was a visible expression of grief that moved people around the world.
Over the last 150 years, the Salish Sea ecosystem has been impacted in profound ways. Once host to the largest salmon fisheries in the world, Pacific Northwest salmon populations have been severely impacted by human activities, including overfishing, dams and toxic waste. The once pristine waters of the Salish Sea have also been denigrated by chemical run-off from major cities and poor water circulation. As top predators on the food chain, orca whales have faced some of the most severe repercussions of human behavior in their marine environment. As a result of these impacts, the Southern Resident killer whale population is hovering on the verge of extinction.
Humans are directly responsible for the demise of the Southern Resident orca whale population. It is up to humans to take immediate action to save this iconic, critically endangered species before it is too late.