March 4, 2021 — The endangered Southern Resident killer whales in the waters near Washington and British Columbia have stalled in their population recovery, and, according to new research, a major factor limiting their growth is their preference for preying on Chinook salmon.
In a study published Wednesday in the journal PLOS One, researchers present new data on environmental stressors facing the orcas and propose investment in the conservation of Chinook salmon to aid in the recovery of the population.
Killer whales are some of the most recognizable mammals in our seas with their distinct black and white markings. While they can be found in every ocean, they have broken off into small populations, creating different sub-species known as transient, offshore, and resident. The three groups are unique to one another, with different physical attributes as well as social structures and behavioral habits.
There are multiple populations of resident killer whales, but the authors of this study looked specifically at Southern Resident killer whales. These orcas mostly inhabit the waters around Oregon, Washington and British Columbia, and make up the smallest of the resident populations.