The eastern North Pacific population is estimated to be 23,000 animals. Today, only the eastern North Pacific population, with more than 21,000 animals, is considered healthy. Since the late 1940s and early 1950s a convention preventing commercial whaling has been adhered to under the International Whaling Commission. Whale lice and barnacles both hitch a free ride. Barnacles eat plankton and food scraps.
Whale lice are parasites that eat whale skin and damaged tissue.
Gray whales are often seen breaching, leaping into the air and splashing back into the water. It is thought that breaching helps gray whales dislodge some of the parasites clinging to their skin. Gray whales have 130-180 baleen plates hanging from their upper jaw. Researcher Jim Darling, a former Vancouver Aquarium Marine Science Centre Research Associate, was able to recognize individual gray whales found on the west coast of Vancouver Island by comparing the variations of their mottled colour patterns. Jim Darling is now a researcher with the West Coast Whale Research Foundation.