Friday, August 24, 2007

Friday orca blogging

[Orcas in Johnstone Strait, 2005]

-- by Dave

Along with the terrific news that a new calf has appeared with L Pod, one of the endangered southern resident killer whale families, we got the depressing news that a barge carrying equipment laden with diesel fuel spilled this week in Johnstone Strait -- directly in front of the Robson Bight, a protected wildlife area known for attracting killer whales.

So far, no whales have been reported harmed by the spill, but the incident raises questions about what's being permitted to ply the waters of the Bight:
Dr. Lance Barrett-Lennard, the Vancouver Aquarium's resident killer-whale expert, spent yesterday nervously counting orcas at the site of Monday's barge accident around the protected waters of Robson Bight.

To his relief, he found all the whales accounted for and none exhibiting signs of immediate distress from the diesel fuel that spilled into their environment. "They appear to be fine -- for now," he said.

But as marine mammal toxicologist Peter Ross explained, breathing and swallowing the diesel can have immediate, though unapparent impacts -- such as lung irritation -- and worse effects later, such as infection and disease.

Most of the light sheen of fuel had evaporated by yesterday afternoon, though, yielding hope that B.C.'s most iconic and beloved animals had escaped the danger.

But the entire episode left Barrett-Lennard wondering just how "protected" Robson Bight really is.

The bight contains a broad pebble beach where the whales gather and exhibit the extraordinary behaviour of rubbing their bodies along the gravelly bottom. It's one of the few places in the world where they do this and it makes perfect sense that it should be strictly protected.

Just one problem: Robson Bight is a provincial ecological reserve, while the movement of commercial shipping and fishing vessels through the area is a federal responsibility. The two levels of government have a committee to work out the jurisdictional overlap, but that doesn't always prevent haphazard interventions into the whales' sanctuary.

During the commercial fishing season, for example, up to 100 boats enter the bight to compete with the whales for salmon.

Regular readers may recall that I visited Robson Bight (actually, we just paddled up to its boundary) last year and watched the orcas frequenting the area. I made a video slide show of it that featured sounds I recorded just outside the Bight.

Now, if you listen carefully, you'll recognize that there's a steady outpouring of noise somewhere in these waters that is part of the ambient sound. That noise was provided by a tug hauling a log boom about 100 yards long (or longer) down the strait, verrrry slowly. It was present for nearly the entire afternoon we watched the whales.

One of the problems with boat traffic, as I explored recently for Seattle Magazine, is that it creates the kind of noise most likely to interfere with orcas' echolocation, which plays a critical role in their hunting (these orcas are strictly fish eaters, and their echolocation frequencies seem specifically geared for chinook, which in fact are believed to constitute the large majority of their diet).

And in Johnstone Strait, as Paul Spong has often noted, the racket can sometimes be deafening for an orca because the strait is so narrow and deep, its sides echoing like the deep canyons they are.

And when you add toxic spills from boat traffic into the mix, the need for change becomes urgent.

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