Tofino wildlife: The Sea Lion Invasion

by Lisa Fletcher, Tofino

You may have heard their barks echoing for miles, or dodged them as they floated by flippers out, but anyone cruising in The Sound a few months ago undoubtedly noticed the massive numbers of sea lions in the water. So where did they all come from?

Sea lions (as well as seals) are known as pinnipeds. The word pinniped translates from Latin as "feather foot," referring to their large flippers. They are both marine and land based mammals, birthing and resting on land but feeding in the ocean. Pinnipeds are divided into two categories: earless seals (seals) and eared seals (sea lions). Eared seals have small external ear flaps and large hairless flippers. What makes the eared seals unique is that they have large front flippers used for body support and can rotate their back flippers under their body so they can 'walk' over rocks.

Sea lions in b.c. were once hugely depended on by coastal people for food and fur, and were hunted commercially between the early 1900s and 1960s. By 1970 however, public sympathy had provoked a response in management strategies to have harbour seals, northern elephant seals, Stellar and California sea lions protected under the federal Fisheries Act.

The sea lions seen in our waters are either Stellar or California sea lions. Stellar sea lions are the largest with adult males reaching up to 10 ft and weighing between 1000 and 2200 lbs-yikes! Their upper body is tan colored and their lower body is a reddish brown. The stellar survives mainly on schooling fish such as herring and pollock, but they have been known to make use of their diving depths of up to 350m to catch octopus, squid or rockfish. They can stay under water for up to fifteen minutes at a time but usually come up after a few.

Stellar sea lions can be found along the coastal rim of the North Pacific Ocean, from California to the Bering Sea and Kurile Islands, usually close to shore. During the end of May and July, most of the population gathers on rookeries to breed--typically the one they were born on. Come late summer or fall, individuals disperse to numerous wintering sites-a behaviour all too familiar to Tofitians. According to Fisheries and Oceans Canada, the population of Stellar sea lions in bc's coastal waters in 2002 was roughly 7000 with 1200 during winter season. Considered a small increase in population size since the 60s, even though it has been protected since 1970.

California sea lions are easily recognizable as the ones with the obnoxious, honking bark that took over Clayoquot Sound in May and June. Only the males travel during the winter, while females and juveniles stay near home. They are much smaller than the Stellar sea lion, males being 8ft and only 900lbs as opposed to their 2000lb cousin. They are dark brown but look almost black when in the water. Known for hauling out on wharfs and log booms, they are often seen resting in 'rafts' all linked together with fins sticking out to minimize heat loss. They can easily be mistaken for porpoises, diving and leaping out of the water. California sea lions also feed on schooling fish, with a small amount of salmon.

There are three populations of California sea lions: the largest population of 120,000 breeds off the coasts of California and Mexico, another breeds off the Galapagos Islands and the third population that is thought to now be extinct, off the coast of Japan. The population off California and Mexico was depleted during the 1800s but has since recovered and is thought to be reaching historic levels—moving further north than ever before.

The population wintering off Vancouver Island is thought to be stable around 3000.

There are still a lot of questions that need to be answered to understand why there are so many sea lions now and what consequence this will have on each individual species as well as other fisheries if the numbers continue to grow. Could both species cause damage to already delicate fish stocks? Or is it possible that the migration of California sea lions could compete with the indigenous Stellar for breeding grounds and food, displacing the Stellar even further North?

Strawberry Isle Research Society is trying to answer such questions by monitoring a newly formed sea lion haulout in Clayoquot Sound that is shared by both California and Stellar sea lions. For more information regarding sea lion research email sisle@island.net

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After finishing her degree in biology this year, Lisa Fletcher wants to tame wild elephants and start a revolution in her spare time.