Ep. 214: Our Southern Resident Orcas are Picky Eaters
Guest: Andrew Trites, Marine Mammal Research Unit at UBC
The southern resident orca whale population is front and centre in the fight against increased oil tanker traffic.
The majestic toothed whale is a member of the oceanic dolphin family. They are also known as killer whales because as a species they will hunt and eat fish, marine mammals; they’ve been known to attack baleen whale calves and even sharks and adult whales.
While, this is true of other orca populations, it is not so with the southern resident population that migrates into the Salish Sea for a couple of months a year. This particular pod has a very limited diet. In other words, they are picky eaters. They really like chinook salmon to the exclusion of just about everything else. They don’t eat harbour seals; they’re not interested in sea lions like their cousins the transient population. Nope, it’s chinook they want and chinook, unfortunately, are a salmon population in distress.
The Salish Sea Marine Survival project is examining a wide range of factors that have contributed to the decline of chinook, coho and steelhead – factors that include eelgrass depletion, a reduction in the volume of phytoplankton and zooplankton, algae blooms, spawning ground distribution as well as great blue herons, harbour seals and sea lions who also love to dine on chinook.
According to Andrew Trites, a professor at UBC’s Marine Mammal Research Unit, our beloved orcas are in danger because they won’t eat other species of salmon, nor will they hunt and eat harbour seals or sea lions. In other words, they are thin due to a very narrow diet.
Add in the disproportionate number of males to females, and the prognosis for the southern resident orca is not good.
We invited Andrew Trites to join us for a Conversation That Matters about what is happening with the Southern Resident Orca Whale population.
