They’re loud and boisterous on land and furry missiles in the water. They’re also pretty entertaining. Whether you love them (like we do!) or not, Steller and California sea lions are a vital part of the marine ecosystem in the Salish Sea. They’re also superbly adapted for a dual life in and out of the ocean!
We regularly see Steller and California sea lions on our whale watching tours from Victoria. In celebration of these playful marine mammals, here are seven reasons why we love sea lions.
California sea lion (left) and Steller sea lion. / Photo by Valerie Shore, Eagle Wing Tours
You’re looking at the photos in this blog and thinking what’s the big deal? They’re probably a little bigger than a harbour seal, right? Wrong. Sea lions are a lot bigger than a harbour seal. In fact, the larger of the two sea lion species we get here—the Steller—can weigh up to 13 times more than a puny 80-kg seal. No wonder seals often haul out some distance away from their big noisy cousins!
Mind you, we’re only talking about the males, which is overwhelmingly what we see here in the Salish Sea. The California boys top out at around 390 kg. The biggest Steller males—with their massive, barrel-shaped Jabba the Hutt-like chests—can reach 1,100 kg. That’s more than a Smart car! By comparison, the girls are about a third of the size.
Mature male Steller sea lion. / Photo by Brendon Bissonnette, Eagle Wing Tours
They’re amazing athletes
To successfully live the amphibious double life of a sea lion, you need a very special body design. For life in the water, your body is streamlined like a torpedo and you use your long front flippers like wings to reach speeds of up to 25 kph. On land, your front and rear flippers can be rotated under your body so you can run on all fours. Faster than a human, we should note.
You’re also superbly equipped for diving. You can slow your heart rate by 80 per cent or so. You can shunt blood to your heart and central nervous system. And you can store oxygen in your muscles way better than any land mammal. Heck, even your nostrils are closed watertight unless you consciously force them open to breathe!
Two young adult Steller sea lions sparring. / Photo by Valerie Shore, Eagle Wing Tours
They’re sociable (sort of)
Here’s where the entertaining part comes in. At haul-outs such as Race Rocks there’s the lounge section and the play section.
In the lounge section, sea lions pile onto one another like rugby players in a scrum. Peace may break out. But not for long. All it takes is one wrong move by one, or a newcomer looking to join, and…turmoil. Roaring, barking, shoving, chest-butting, mouth-to-mouth threats. “Get your flipping flipper off me.” “Get out of my face.” “This is my rock.” Eventually they sort it out. For a few minutes anyway.
In the play section the young males spar, wrestling, shoving and biting one another. It’s just horseplay here. But in a few years, those combat skills will come in handy at the sea lion singles bar. Only the biggest and strongest get the girls. See #5.
Male California sea lion, dozing. / Photo by Brendon Bissonnette, Eagle Wing Tours
They’re seafood connoisseurs
Sea lions can eat up to seven per cent of their body weight every day. Youngsters need twice that amount. So it’s a good thing that the Pacific Ocean buffet has lots to offer. They’ll go after pretty much any fish that swims by, including herring, sandlance, mackerel, pollock, cod, small sharks and rockfishes. They also eat octopus and some squids.
What about all the salmon they eat, you’re wondering? In reality, salmon make up only a small fraction of a sea lion’s annual diet. In fact, they eat a lot of the fish that are predators of young salmon. Marine food webs are complex!
Steller sea lion eating a spiny dogfish. / Photo by Selena Rhodes Scofield, Eagle Wing Tours
They’re passionate lovers
Remember the singles bar reference we made in #3? They’re a walk in the park compared to a sea lion breeding rookery. Every year in late spring, the testosterone-fueled males head for the rookeries (further north for Stellers, south for Californias) to try their luck with the girls. Most will fail.
Here’s the playbook for sea lion “courtship”: step one—stake out a territory on the rocks, usually up to 200 square metres; Step two—keep all other males out by any means necessary, including threat displays, neck-fencing and sometimes all-out fighting. Step three—“introduce” yourself to any female that blunders into your territory. Presto—a baby sea lion is the result one year later.
If this all sounds pretty exhausting, it is. Some alpha males defend their territories for as long as two months, living off their body fat the whole time. It’s a fantastic weight loss program. They can burn off up to 20 per cent of their body fat!
Steller sea lion pup with mom. / Photo by Valerie Shore, Eagle Wing Tours
They’re good moms
Then there’s the female perspective. You arrive at the rookery and it’s full of enormous, blubbery, feuding males. You clamber your way through all the drama and within days, you give birth to a single bawling pup. You nurse junior for 10 to 30 days then, feeling a tad peckish, you head for the water and hopefully a fishy snack or two. Wait, not so fast, says Mr. Sea Lion, proprietor of the territory you’re in.
Yes, that’s right, females get knocked up while still nursing their new pups. They’re good moms, though, and continue to alternate nursing duties with foraging expeditions. Most pups are weaned within a year, but some continue to suckle into their second and third years. A few tolerant Steller moms have been seen nursing newborns and yearlings at the same time!
A mix of Steller and California sea lions. / Photo by Valerie Shore, Eagle Wing Tours
They’re essential to this ecosystem
These days, sea lions get a lot of bad press. We hear talk about an uncontrolled “population explosion” and how they’re eating up all the salmon. But here are some facts. We’ll let you decide.
Yes, sea lions are predators of salmon. But so are more than 135 other species including eagles, killer whales, bears, blue herons, many types of fish—and humans. Many things are causing the salmon decline. The main ones are global climate change and warmer ocean temperatures; habitat loss due to logging, dams and coastal development; decades of overfishing; and disease and parasites spread by fish farms, to name just a few.
In the early 20th century, Steller sea lions were viewed as competitors with humans for salmon. Decades of culls followed. By the time Stellers were protected in Canada in 1970, the population had plummeted to about 25-30 per cent of its historical size. Their numbers have since recovered to natural historical levels.
Steller sea lion. / Photo by Karac Lindsay, Eagle Wing Tours
Did years of sea lion slaughter help the salmon stocks? Research off northern Vancouver Island suggests not. There was little evidence that historical culls had any positive effects on salmon catches.
California sea lions were never culled in Canada. But off the US coast, uncontrolled killing for commercial purposes drove the population down to as low as 1,200 before they were protected. Their numbers have also rebounded to natural levels. More are now being seen in BC waters, probably in response to changing ocean conditions and a shifting food base.
Sea lion numbers are naturally regulated by the mammal-eating transient (Bigg’s) killer whales—which rely on a healthy sea lion population for food. Steller sea lions alone make up 13 per cent of the diet of transient killer whales.
Book a tour with us and come out and see these amazing marine mammals for yourself!
Blog written by Valerie Shore, marine naturalist with Eagle Wing Tours.