Pinnipeds

The abundant fish in Cowichan Bay make it a popular destination for both seals and sea lions. A big sea lion may eat as much as 16 kg (35 lb) of fish each day! However, what’s good news for seals and sea lions is not such good news for the rivers’ salmon runs. The increasing drought conditions in our watersheds can leave large numbers of salmon waiting in the estuary for increased river flows, making them easy targets for seals and sea lions.

Sea Lions

How do you know it’s November in Cowichan Bay? You can hear and smell the male Steller sea lions (Eumetopias jubatus). These big boys visit Cowichan Bay every November to feast on the salmon returning to the Cowichan and Koksilah Rivers on their way to the spawning grounds. Weighing up to 800 kg, male Steller sea lions are so big that one or two of them can sink a small sailboat, as some locals have recently learned the hard way. Steller sea lions are quite gregarious and communicate with loud roars and deep growls. These sea lions are shallow divers and can hold their breath for approximately 16 minutes underwater. California sea lions (Zalophus californianus) also visit Cowichan Bay to feast on salmon in November. California sea lions are smaller and darker in colour compared to Steller sea lions, and mature males have a bump on their forehead called a sagittal crest.

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Steller sea lions gather at the breakwater in Cowichan Bay every November. Male Steller sea lions can reach a height of 3 meters, and can weigh up to 800 kg. The locals affectionately call the annual gathering at the marina, a “bachelor party.”
Here we see a Steller sea lion that has just caught a fish, likely Chum salmon. Sea lions feast on salmon returning to the Cowichan and Koksilah Rivers to spawn and complete their life cycle. In British Columbia, Steller sea lions eat mainly schooling fish such as salmon, herring and sardines.
Steller sea lions have a distinctive, low frequency roar. Male sea lions seen here use sound to communicate with each other or to defend their territory. At rookeries, females use sound to find their pups. In fact, British Columbia is home to the world’s largest rookery on Triangle Island off the northern coast of Vancouver Island.
Steller and California sea lions rest on the dock at Cowichan Bay. California sea lions are smaller and darker in colour compared to Steller sea lions. Sea lions are social animals that can often be found resting together (and on top of each other) on docks. They also mingle with each other in the water and can create a floating raft of sea lions!
Sea lions sometimes rest on boats in the marina. Unfortunately, they leave smelly feces, and their heavy weight can lead to boat damage. To help reduce the population of sea lions, a First Nations group applied for a commercial license to harvest sea lions in Cowichan Bay. The permission was not granted by the Department of Fisheries and Oceans, and the controversy continues on how humans can coexist with wildlife.

Photo Credits: Eric Marshall

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Listen to California sea lions barking underwater. The sound was recorded using a hydrophone (an underwater microphone) near Denman Island during the wee hours (~2am) of March 11, 2020. Audio Credit: Philina English, Fisheries and Oceans Canada

Seals

Harbour seals (Phoca vitulina richardsi), sometimes as many as 100, can be found year round in Cowichan Bay. They can be seen hauling out on the log booms, but not on the breakwater because it’s too high. Harbour seals feed on a variety of fish and an individual seal may eat 5 to 7 kg (12-15 lb) of fish per day.

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