Every winter off Hornby Island, divers plunge into the undersea den of some very playful and gregarious Steller sea lions! A pack of about fifty or more sea lions were sprawled on the rocks just metres from the dive boat as the skipper steered his vessel closer to the tiny islets known as Norris Rocks. The sea lions loudening chorus of raucous groans and guttural barks now competed with the sound of the snarling winter wind that was chilling to the bone. It appeared as if the sea lions were eagerly anticipating our arrival as several had already plunged into the water and were frolicking around the skiff’s anchor line, seemingly beckoning us to jump into the sea.
I had not yet reached the sea floor forty feet below when two sea lions whirled past me, spinning and turning as they flew by. Settling down on the bottom, I readied my underwater camera and commenced shooting. Diving with several curious and playful sea lions is certainly a wonder to behold. Looking over at my wife, Kathryn, I could see a female sea lion inquisitively peering into her dive mask, almost as if to give her a kiss. Directly in front of me, two sea lions were quite literally standing still and posing for me as another sea lion teasingly was yanking on one of my fins. I was so excited with the large number of sea lions cavorting around us, that I exposed an entire roll of 36 frames of film in less than twenty minutes! This experience left no doubt in my mind that everything I had ever heard about the marvelous sea lion encounters at Norris Rocks was indeed true.
Norris Rocks are a series of remote rocky islets situated off Hornby Island, on the eastern edge of Vancouver Island. Each winter between December and April, Steller sea lions haul out in large herds at Norris Rocks to feed on herring that are gathering to spawn. The male, or bull, Stellar sea lion is a huge thick-maned animal that weighs in at about 700 to 1,000 kilograms, with a body length of up to three metres. The females, or cows, are about a third as large tipping the scales at 300 kilograms and are 2.3 metres in length. Steller sea lions (Eumetopias jubatus) are named after Greg Wilhelm Steller, the eminent German naturalist who accompanied famed Russian explorer, Vitus Jonassen Bering, in 1741 on his second Alaskan expedition to Kamchatka Peninsula. During a long winter, shipwrecked on Bering Island, Steller became the first scientist to study and classify these sea lions along with a number of other animals.
Sea lions are not regarded as being dangerous to sport divers even if provoked in some way. Generally, Steller sea lions will not deliberately attack a human. While bull Stellers are intimidating based on their immense size alone, the females will occasionally bluff-charge divers by blowing bubbles and rush towards them at speeds of 30 kilometres an hour before gracefully veering off at the very last second. The basic rule to follow when diving with sea lions is to maintain a respectful distance from rookeries during the mating season when males become aggressive or during the birthing season where either sex will defend their pups. Sea lions typically will come from offshore to visit you if you maintain a safe distance from their rookeries while in the water. It is almost guaranteed that they will choose to stay and play whenever divers are nearby in the water.
Steller sea lions are social animals. Playtime to these inquisitive and mischievous pinnepeds usually entails slowly approaching divers to stare curiously into the diver’s mask, or mischievously nipping on a diver’s flippers. At Norris Rocks, the sea lions love to interact with divers and obviously enjoy mimicking our behaviour and giving playful tugs on ones limbs and scuba gear. While their skulls are similar to those of bears and their jaws contain sharp canine teeth much like those found in dogs or other flesh eaters, when they gnaw divers it feels more like a mild jerk or a pull. This gentle physical curiosity seems to affirm that a sea lion’s bark is worse than their bite.
Observing these magnificent sea mammals swimming underwater is akin to having a front and centre row seat at a spontaneously choreographed aquatic ballet. Breakneck swimmers, Steller’s can swim in burst speeds up to 25-30 knots (30mph), but generally cruise at about 5-15 knots (11mph). They generate speed by leaping clear of the water in a maneuver called porpoising, and then glide near the water’s surface to minimize resistance. The bone structure of their wing-like front flippers is similar to that found in human’s arms and hands. Quite literally, they fly through the water by making long simultaneous sweeps with their front flippers and use their hind limbs for steering. Remarkably, they are quite mobile over rocky terrain since they are able to rotate their hind flippers underneath their body enabling them to walk by using all four flippers.
Stellers can linger underwater for as long as 15 to 20 minutes on a single breath before they must resurface for air. Generally, they only remain underwater for brief forays between 2 to 6 minutes. While the deepest dive recorded for a Steller sea lion is 424 metres (1,391 feet), divers usually interact with them at shallower depths. Unlike true seals, that empty their lungs before diving, sea lions only partially deflate their lungs, allowing them to vocalize underwater. This ability to bark and grunt while submerged is used by males when patrolling their underwater domains. Sea lions are able to make deep dives and remain submerged for extended periods due to their extreme tolerance of carbon dioxide. When underwater, the oxygen in their body is shunted to vital organs such as the heart and central nervous system rather than non-vital organs. Marine biologists speculate that this physiological response may also prevent them from getting “the bends”.
Carnivorous and “opportunistic feeders”, sea lions obtain most of the water their body needs from the food they eat. Stellers consume 6 to 7 percent of their body weight each day, surviving mainly on herring and other oily fish in addition to squid, skate, small sharks, octopus, ratfish and seabirds. These highly social creatures congregate in large colonies on rocky islets called haul-out sites, that are used for breeding and raising young. The strongest bulls compete with each other to maintain a harem of fifteen to thirty females, and defend their territories for up to sixty days. Bull Stellers will not eat during the breeding season for fear that they might lose their females to a competitor.
A curious piece of trivia about Stellers is that marine biologists have discovered that the stomachs of many adult sea lions contain stones! These rocks vary in size from small pebbles to 12 centimetres in diameter. No one has ascertained whether these stones are swallowed by accident during play or if they serve a useful purpose such as; grinding up fish in their stomachs, providing ballast when diving, or help ward off hunger pangs when the animals are fasting on shore.
Diving in the wild with Steller sea lions offers sport divers a thrilling “big animal” encounter that is on par with diving with dolphins, sharks or whales. One cannot help but marvel at their graceful swimming ability and their seemingly child-like penchant for having fun underwater. Their playful underwater antics provides an adrenalin rush that is guaranteed to warm both one’s heart and the biting chill of winter.
GETTING TO HORNBY ISLAND
From Nanaimo, drive north on the new Island Highway for about 50 minutes and follow the road signs to the Denman Island Ferry at Buckley Bay (located 20 kilometres or 13 miles south of Courtenay). A 15-minute ferry ride takes you to Denman Island where, after a 15- minute drive, you can take the connecting 10-minute ferry crossing to Hornby Island. From the Hornby Island ferry landing, follow the main road to Ford Cove and Hornby Island Diving. Be sure to allow extra time for sailing waits and delayed ferry crossings during peak tourist season, especially from the mainland to Nanaimo. Although most visitors arrive by car using the BC Ferry system, Hornby Island can also be accessed by floatplane from the South Terminal at Vancouver International Airport or by a scheduled flight from Vancouver to Comox.