Scientist: Increase In Seal Population Likely Attracting More Sharks To Maine Waters

Jul 28, 2020

The Maine Department of Marine Resources has identified Julie Dimperio Holowach, of New York City, as the victim of a shark attack near Bailey Island yesterday. She was pronounced dead after being helped to the shore following the attack.

It may be the first recorded encounter of its kind in Maine and has sparked beach closures in parts of the state.

Dr. Nick Whitney, senior scientist and chair of the Fisheries Science and Emerging Technologies Program with the New England Aquarium in Boston, spoke with Maine Public's Nora Flaherty about why there might be more sharks in Maine now than there have been in the past.

Dr. Whitney: I think it's generally accepted that the increase in number of seals is leading to more white sharks coming closer to shore during some months. Other than that, I'm not sure if there's been any major changes in migration patterns. Sharks have probably been using these waters for decades or longer.

Flaherty: Is there anything pointing to a reason why - why the shark is there?

Maine's coastal waters have plenty of seals. Seals are a major prey item for white sharks. And so when you have prey items around that's going to attract the predators.

Sharks also have certain habits in terms of how they hunt, and their life cycles that might possibly have contributed to this, correct?

The assumption in these waters is that if it was a large shark that bit the person that it was probably a white shark. And we know that white sharks tend to move into this area more commonly in the summer months. Every year they tend to peak, at least around Cape Cod they'll peak in August, September, and then start to move south as the waters get cooler. So this is a normal part of the shark's movement cycle to be up in these waters at these times.

And how might we anticipate reducing interaction between humans and sharks if that trend does continue, and we do see more sharks in Maine waters?

I think it's just something where people just need to be more aware of their surroundings and just recognize that there's a risk. If you're going into the water in an area where there are seals, and especially if it's in the summer months when we know white sharks are more likely to be around, there's going to be the possibility - as rare and unusual as it is - there is going to be the possibility that you encounter a shark. You know, at the New England Aquarium we study a number of shark species in the local waters here. White sharks aren't the only species that are around. Most of our research involves studying the impact of humans on sharks, and the impact of fisheries. Even though it's always a tragedy when something like this happens - a shark bite on a person - overall, the number of sharks that are killed by humans every year just drastically outnumbers the number of humans that are bitten by sharks.

So you feel we could keep the beaches open.

That's always a matter of the individual beach and the public safety officials there. I think it is a good idea to do what they normally do, which is close a beach in the immediate aftermath of a bite. But there's no indication that a shark who bit a person is going to be around in that same area a day later, or certainly several days later. People used to believe that sharks were incredibly territorial and would stake out a beach and if someone was bitten off that beach, that fisherman needed to go out there and catch and kill every shark they could in the hopes of getting the culprit shark. Now we know that that's not the case at all. The shark that bit a person is likely tens, if not hundreds, of miles away within, you know, the next day or two after the bite. So very little evidence that it helps at all to go out and catch sharks after an attack.

Nick Whitney is senior scientist and chair of the Fishery Science and Emerging Technologies program with the New England Aquarium in Boston. Nick, thanks so much.

Yeah, my pleasure.

This interview has been lightly edited for clarity.