Starboard spectacles

Posted: August 26, 2014 at 12:13 pm   /   by   /   comments (0)

By Ben Chessor

The ocean has always been an important part of Vancouver Islanders’ livelihoods. It fuels local tourism — including the whale watching industry — and gives flavour to our best restaurants. An orca even appears on the logo of the province’s most popular sports franchise, the Vancouver Canucks.

Because the ocean plays such a large part in the lives of Island residents, whenever some of the Salish Sea’s most majestic inhabitants make an appearance, their neighbours are bound to take notice. That’s especially true if there are a thousand of them:

Vancouver resident Rob Maguire’s November, 2013 encounter was just the start of a particularly busy period of marine sightings in the area. In February, passengers aboard a ferry leaving Nanaimo’s Departure Bay recorded a pod of dolphins taking cover around the vessel as they were being hunted by orcas.

And in March, approximately 150 dolphins, once again pursued by orcas, made an unexpected appearance in Howe Sound near Vancouver.

Some even made their way into False Creek, in the heart of the city.

— Theresa Shaw (@tshaw3000) March 16, 2014

Tessa Danelesko, the Coordinator of the B.C. Cetacean Sightings Network, thinks these increases are part of a continuing trend that the public is just beginning to notice. “Since the mid 1980’s, there has been an increase in the amount of Pacific White-sided dolphin sightings because they are spending more time in coastal waters,” she writes in an e-mail. “The reason for this shift remains a mystery, but it may have something to do with changing ocean temperatures and prey abundances.” In other words, there are more dolphins for the orca to hunt because there are more herring for the dolphins to hunt.

Cleaner waters may also account for the change. “In the early 2000’s most of the industrial activity in Howe Sound ceased, ending the flow of hazardous pollutants into the sound’s waters,” Danelesko notes. “In recent years the Sound has shown signs of recovery. Fish and marine life that had previously been eliminated are starting to make a comeback.”

Pacific White-Nosed DolphinsWhile there may be more of them these days, Pacific White-sided dolphins have long been a common sight off the Island’s coast. When fully grown, the dolphins can weigh as much as 440 pounds and reach more than two meters in length. They aren’t very picky hunters, and will eat pretty much anything they can find. Salmon, herring, pollock, squid and shrimp are their favourite dietary staples.

Experts suspect that there are as many as 25,000 Pacific White-sided dolphins in the Vancouver Island region, although their affinity for riding shotgun with boats may cause the number to appear larger than it actually is. Typically they travel in pods of around 80-100. Sightings of 1000 remain extremely rare.

Research into the animal is ongoing, including a project being conducted by Vancouver Aquarium research associate Kathy Heise which is attempting to better understand how dolphins use echo location in order to detect and capture prey, while also avoiding hazards such as underwater nets. Sightings such as the ones in Howe Sound and Departure Bay are extremely helpful to researchers, especially when they are recorded. Danelesko says such “resights” allow them to compare photographs and videos like the ones taken in Howe Sound with past sightings to see if the same pod is involved.

They also allow the public to get involved. “If anyone spots a cetacean along the B.C coast, they can report their sighting to the B.C Cetacean Sightings Network,” says Danelesko. “Sightings gathered from the public help researchers gain a better understanding of where cetaceans spend time along the B.C. coast.” Reports can be submitted online at wildwhales.org , by email at sightings@vanaqua.org or by calling the toll free hotline at 1.866.I.Saw.One (1-866-472-9663).

While many questions remain about the Pacific White-sided dolphin, one thing is certain: If you keep your eyes peeled next time you’re on the ferry, you might just be pleasantly surprised.

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