Orca Communities in a Fragile Environment

Orca communities form different species or ecotypes, each with unique acoustic behaviors, feeding habits and prey preferences. Occasionally, the range of these different orca overlaps but they never interbreed and they rarely interact. Orca are top predators and unfortunately they accumulate pollutants that are transferred through the food web which become stored in their blubber and can be passed along to nursing young.

Transient Killer Whale off Vancouver Island Coast.

In the northern hemisphere we have three ecotypes:

Offshores found in the North Pacific, which are rarely encountered. These are the smallest of the three northern ecotypes. Offshores live far from land over the outer continental shelf with massive ranges stretching from Southern California to the Bering Sea. Very little is known about their social structure and prey preferences however, the teeth of offshores are often worn, indicating they feed on rough skinned prey such as sharks. They have been viewed in large groups of 50+ individuals.

Transient Orca or Bigg’s, which regularly visit the Tofino area, are mammal-eating. Transients live in small groups. These orca, travel from California to the Arctic in large home ranges. Like most orca, transients are very family-oriented, forming tight relationships with their relatives. Some offspring stay with their mother for their entire lives.

Resident Orca are the fish-eating specialists. Residents have small ranges that surround large fish populations. Residents are found on both sides of the North Pacific. These orca form separate family groups within larger communities and have fish preferences depending on the areas they inhabit. Near Victoria British Columbia, the endangered Southern Residents love salmon.

Transient Orca in Tofino Harbour.
Transient Killer Whales in Tofino, BC.

On December 21st, another member of the endangered Southern Residents, J34, was found dead near Sechelt, BC. The necropsy showed that the 18 year old orca died of blunt force trauma to the head. A hematoma indicated J34 was alive for a time after his injury, which may well have been caused by vessel contact. At least three other animals in the group have died this year, including a calf, a 23-year-old female called J28 and a male known as L95.

Paul Cottrell, Pacific marine mammal co-ordinator with Fisheries and Oceans Canada says “there are now only 79 whales left in the population.”

This past November, the federal government finally stopped the Northern Gateway proposal and vowed to impose a north coast oil tanker ban. While they rejected the Northern Gateway, they approved Kinder Morgan’s Trans Mountain Expansion, which has plans to deliver 890,000 barrels of tar sands oil per day to Vancouver. Oil-tanker traffic through the Salish Sea surrounding Victoria and the southern areas of Vancouver Island would see a seven-fold increase above existing levels to more than 800 in-and-out bound transits annually.

This tanker traffic goes through the endangered Southern Resident killer whale habitat. Not only is the probability of an oil spill high, the noise from these tankers alone could increase the chance of extinction for the Southern Resident population. The cumulative effects of pollution, noise, and the likelihood of collision and oil spills make extinction highly probable.

Sunk Vessel off Vancouver Island
Oil spill cleanup off BC Coast

Recovery for these fragile Residents may be possible only with lowered vessel disturbance, noise reduction, and help increasing Chinook salmon stocks. However, should there ever be an oil spill in the Salish Sea, not only could the Southern Resident Orca population be destroyed, but coastal communities like Tofino and Ucluelet would feel the devastation along our fragile shores as well. Lets do our best to protect these amazing endangered species!

By Ocean Simone Shine