Trash can be torture for wildlife
Dedicated teams struggle to rescue Steller’s sea lions entangled in plastic debris
VANCOUVER Marty Haulena positioned himself atop a federal Fisheries patrol boat, his CO2-powered dart rifle aimed at a rocky haulout of about 200 Steller’s sea lions off Long Beach on Vancouver Island.
His target was an adult female with a plastic packing band cutting through the skin and deep into the blubber around its neck.
“A lot of things can go wrong,” the Vancouver Aquarium veterinarian said of the rescue mission. Humans may be injured by slipping on wet rocks or working around a wild animal weighing at least 300 kilograms. An anesthetized sea lion is also at risk of drowning should it leave the safety of the rocks and plunge into the Pacific Ocean.
To do nothing also has its consequences: a slow and painful death for the sea lion.
“These animals are going to die, based on every survey and photographic evidence we have,” Haulena explained. “They’re going to die in a really bad way.”
Fisheries officer Denise Koshowski guided the 7.3-metre inflatable boat ever closer to the noisy, nervous colony. At a distance of 20 metres, Haulena fired the gun and watched the dart hit its mark and then quickly bounce onto the rocks, leaving him uncertain if the animal received the full 4.6-millilitre cocktail of medetomidine, butorphanol and midazolam.
The drugs take about 12 minutes to fully take effect, enough time for Haulena and assistant Chelsey DeColle to be dropped off on the other side of the islet so they can approach the animal from above and behind.
The other sea lions shuffled quickly down into the water to form a synchronized herd of slippery bobbing heads in the undulating waves. The darted female sleepily bobbed its head but remained behind. Haulena worked his way toward her and successfully snipped the packing band.
The startled sea lion rocketed into the water and the heart-in-throat phase of the rescue began. The drugged animals can fall asleep as easily in water as land, Haulena explained, but “their reflex to lift the head and breathe remains intact.”
Crews on the fisheries vessel and a second 8.4-metre chartered inflatable kept tabs on the sea lion, prepared to intervene as necessary.
Parks Canada warden Tanya Dowdall reached down with an aluminum fishnet frame to restrain the animal and keep its head above the surface, only to watch it surge away with the contraption around its neck.
When the animal resurfaced again, vet technician Emily Johnson reached down and removed it.
Usually, when a tranquilized sea lion enters the water, the animal is held between the two boats while
it is administered a combination of atipamezole and naltrexone to reverse the effects of the anesthetic. In this case, the animal is allowed to swim freely.
Another successful, if harrowing, rescue.
Steller’s sea lions are named for German surgeon and naturalist George Wilhelm Steller, who described them in 1742.
Aquarium associate researcher Wendy Szaniszlo has helped monitor the species for years out of her base in Ucluelet. A total of 620 entanglements of Steller’s and California sea lions have been recorded
off Pacific Rim National Park Reserve, mainly Barkley Sound, from 2005 to 2013. Allowing for duplicate sightings during surveys, the number probably represents about 335 individual animals.
About 38 per cent of cases involved plastic packing bands. A further 10 per cent involved commercial and sport fishing gear, five per cent rubber bands from crab traps. For the rest, debris was so badly embedded the type was unrecognizable.
Over the past two years, the aquarium has successfully rescued a dozen sea lions on Vancouver’s west coast and near Fanny Bay, south of Courtenay in the Strait
of Georgia.
It’s not cheap, at about $2,000 per expedition. And no one sees it as a permanent solution.
That would require development of both a biodegradable alternative to the plastic bands and for humans to take responsibility for their actions: ensuring that plastic packing bands are snipped — just as you should for plastic over a sixpack of beer — and disposing them properly.
“It a shake-your-head moment,” Johnson said. “We’re such a throwaway society.”
Haulena took up the thought: “We’ve never seen one get entangled. I don’t know if it’s completely random or they start nosing at it and playing with it then it slips on and doesn’t come off. Their hair prevents it from coming off at first, then as they grow it digs in and has a cutting action, sawing through the skin.
“No one’s kidding anyone. Saving one sea lion... with a whole pile of people won’t solve the issue. We need to solve it on the front end, dealing with garbage and materials that won’t affect our animals in this way.”
During rescue missions, the team gives priority to females over males given their greater importance for reproduction, and Steller’s over California sea lions since the former is officially a species of special concern and the latter is not.
Haulena said that permits to dart sea lions in the U.S. “were pulled” in the late 1990s due to excessive deaths but that development of alternative drug combinations has greatly improved the odds. Federal fisheries officials issue permits for the aquarium’s B.C. rescues.
Despite deadly marine debris, the B.C. population of Steller’s sea lions continues to grow. A 2013 survey showed 6,089 pups and 22,300 non-pups, representing annual average increases of 4.6 per cent and 3.7 per cent, respectively, since 1971.
The world’s largest Steller’s sea lion breeding colony is Triangle Island, off the northern tip of Vancouver Island, with 3,985 pups in 2013.
On the whole west coast, Szaniszlo estimates one per cent to two per cent of the population is entangled.