Thursday, December 31, 2009

Rescue frees Steller sea lion tethered for days to Race Rocks, unable to feed

A male Stellar sea lion entangled in ropes got help from Department of Fisheries and Oceans and Vancouver Aquarium staff.
Victoria, B.C. - A juvenile male Steller sea lion is expected to make a full recovery after being entangled in ropes that had tethered it for days at Race Rocks.

A team of marine-mammal experts performed a brief but tricky rescue on the four- to five-year-old male Thursday that ended with the mammal swimming free.

It was an unusual but fortunate situation to have the 320-kilogram animal tethered to the rocks at the ecological reserve in the Strait of Juan de Fuca and unable to swim away.

"With any kind of sedating, the [sea lions'] first response is to jump in the water and they sink and drown," said Paul Cottrell, Pacific marine mammal co-ordinator with the Department of Fisheries and Oceans.

"We got confirmation on Wednesday it was actually tethered."

Twisted rope anchored in the rocks at the surf line was wound very tightly around the animal's left flipper. That meant the sea lion had a small circle to travel but couldn't feed. The animal appeared to be underweight, said Cottrell.

"It's often unfortunately the case that with the technology we have available, we have limited options for some of these animals," said Martin Haulena, a veterinarian with the Vancouver Aquarium.

It takes time for a sedation dart to take effect, which means human helpers can't approach a creature in distress immediately, he said.

"The really great part here for us — not for the animal, obviously — was the animal was tethered to the rock. We thought it was one of the best chances we've had in a long time for disentangling a large Steller sea lion."

There were significant challenges in getting close to the sea lion to deliver the dart while fighting currents on bouncy seas, Haulena said.

A fisheries officer took the rescuers out from Pedder Bay and navigated the swift currents and big swells where the sea lion was tethered.

The crew had to work fast after giving the sea lion a drug reversing the effects of the sedative while they worked to get the rope off its flipper.

"The sea lion was able to lift its head and keep breathing but wasn't really able to generate any big motions," Haulena.

The operation took a very short time, he said. Normally, they would have taken blood sample for further analysis but this time they decided not to delay things more than necessary.

The wound appeared clean and has a good chance of healing, Haulena said.

"Based on quite a few entanglements we've done, I'd say this animal has a really good chance of recovery," he said.

This is about as far from a clinical setting as you can get but it can be interesting, Haulena said. "That's the fun work — we apply medicine to neat species in bizarre places."

Race Rocks is a prime place to spot entangled Steller sea lions because they like to gather there and are visible by boaters and the Lester B. Pearson College's eco-guardian.

This one, once released, appeared a little dopey but had no trouble swimming away, said Cottrell.

This incident highlights the dangers man-made materials pose to marine fish and animals, he said.

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