Shark expert: Respect them like bears
A Dalhousie University shark expert says we should be treating the ocean predators like we do bears in the woods.
It's timely to have the discussion, Fred Whoriskey, executive director of the Ocean Tracking Network, said on Wednesday, as Discovery Channel's Shark Week stirs up a lot of interest, as it does every year.
“It's certainly a public relations bonanza — gets people thinking about sharks,” Whoriskey said. “To the extent that it gets people terrified about sharks, it's probably not a good thing.”
He said people need a little more rational thinking surrounding the topic of sharks in Nova Scotia waters and the associated risks.
“When people head out to go for a hike in a national park and they know that there are bears there, they're rational about this. It's a top predator, it's potentially a dangerous animal, but we don't stop going hiking in national parks. We take certain precautions in terms of what we do, how we do it, and how we minimize our ... not so much our interactions but our risks an interaction would bring.
“What's happened with the sharks is we tended to forget that. Forget that we have a part to play in controlling these interactions and that if we do do that, we can certainly enjoy our waters and have all of the fun and activities on the beach but do so without antagonizing or aggravating or agitating some of these large predators that actually call the ocean home.”
Whoriskey said our society has fallen into a mode where we've forgotten that they've always been here, although the populations were reduced by overfishing and other human interactions.
“They got so low that effectively, in many people's minds they weren't out there,” he said. “And conservation measures that have been put in place are beginning to restore populations, to restore the ecosystem functions and roles they played in the ecosystems. But that means that they're going to be around. We got to get back to what we used to think about these and the the kind of personal responsibilities we take surrounding that.”
Whoriskey said there are populations of what he called “our resident sharks” that hang around in our waters all year long. Those include the Greenland shark, porbeagles, and things like the black dogfish that no one ever encounters because they are deep water species.
Other sharks like great whites follow the food from southern waters when production lines turn on in the spring and summer and autumn.
“Then we get an influx of other species like the mako sharks and the blue sharks and dogfish — spiny dogfish — that at this point in time move in and profit from that. And they'll hang around from the spring and summer and then as the winter is closing in, they go find some place that is warmer and kinder for them for that period and then return again in subsequent years.”
A further contributor to that is climate change, he said.
“We know it's warmer. Increasingly, Halifax and the Maritime region are beginning to see species that we would have formerly considered odd strays that came in but nobody really knew why but are now cropping up year on year and are coming from much warmer climates and they're making themselves known on such a regular basis that they're probably beginning to become part of our local fauna.”
Whoriskey's fellow researchers are beginning to see more and more tiger sharks that have been tagged by colleagues in the southern United States being detected on OTN'S acoustic telemetry systems off of Halifax. And a group of Dalhousie students actually caught a small tiger shark a couple of years ago not far off Halifax.
Shark attacks are extremely rare but they have happened. A woman in Maine died last year after a shark attack.
With more and more people using the ocean, Whoriskey said the numbers game is increasing the possibility of encounters.
“The second thing is, as the water warms, so does the inclination to go swimming,” he said. “Back 20, 30 years ago, when the water temperature rarely got above 10 degrees centigrade, it really wasn't that much fun to go for a long swim in the ocean. ... Now, we're collecting seahorses on a regular basis off of Halifax and getting surrounded by schools of tropical fish as you go diving. So that is changing the probabilities of encounters.”
The rebounding population is a third factor, such as with the white sharks.
“Where before, we weren't detecting too many — and in fairness, we only recently really began to start major tagging programs for these animals. But having said that, we're beginning to detect a number of hot spots off the Maritime coastline, places where 14 or 15 tagged white sharks were being detected in a very short period of time.
“And they're coming up year after year to the same places. Some of them, anyway. And what that's telling us is they're beginning to learn this migration pathway. They are learning that this is a good strategy — a successful strategy — for me to grow and feed and do well, so we're going to see more of that.”
He said that leads back to being shark-smart and thinking about bears in the woods. You want to be careful and understand that there are predators out there.
Whoriskey said dawn and dusk are hunting periods for sharks, “so frolicking alone in the water with the seals in places where the sharks are hunting at those particular times is really a very bad idea. You wouldn't do that with a bear if that was in the woods, and why would you want to do that with a shark area in the ocean? So getting focused in on those kinds of things is very important.”
And don't go in the water if you're bleeding from an open wound.
Sites where there's no food will be of zero interest to sharks, he said. So beaches with no seals or fish congregations are great places to enjoy.