Planning a Cape Cod National Seashore vacation? Educate yourself about great white sharks/NPS

They are the main course for great white sharks: Eight hundred pounds of fat and muscle wrapped up as gray seals. And with thousands of these seals spending the summer in the waters and on the beaches of Cape Cod National Seashore on the Massachusetts coast, they've attracted more than a few great white sharks to the seashore's waters, which can be a problem for summer crowds looking to cool off in the Atlantic and even Cape Cod Bay. 

Last week a shark, possibly a great white, bit a New York man while he was standing about 90 feet offshore of Longnook Beach, a Truro town beach surrounded by the national seashore. The man, hospitalized in serious condition at a Boston hospital with wounds to the left side of his left hip and thigh, is believed to be the first swimmer attacked by a shark at the seashore this summer.

The man, vacationing with his family, had gotten into the water and swam to the north, and then back to the south, said Cape Cod National Seashore Chief Ranger Leslie Reynolds during a call Friday. 

“He’s still in serious condition, so my rangers have yet to formally interview him. Lots of witnesses are saying (he was) 30 yards (from shore), but we have not heard from him exactly how far he was yet," she said. "I will tell you that it was high tide.”

The number of sharks, and seals, in the area prompted the Truro Town Council to close Longnook Beach on Friday evening, and there have been intermittent closures of other beaches in the national seashore when sharks are spotted.

Luring the sharks close to shore are the 15,000 or so gray seals in the Cape's waters. Once plunging in population due bounties placed on them from the late 1800s until about the 1960s, the species has bounced highly back in number thanks in large part to the Marine Mammal Protection Act of 1972.

Gray seals, here with harbor seals spotted near Chatham, can weigh up to 800 pounds and chow down on more than 30 pounds of fish a day/Meghann Murray, NEFSC/NOAA

"Certainly, there'™s lots of controversy relating to the recovery of seal populations in New England," Dr. Bob Cook, a biologist for the national seashore, told me a few years back. "Essentially you have a population of adults, including myself, that grew up during a period of time when seals were exceedingly rare in this part of the country. And a whole way of life developed in the absence of seals that is now considered to be the norm.

"And now that there are seals here, there'™s a whole bunch of people who are concerned that the presence of seals makes it impossible for them to go fishing, that you can no longer engage in surf fishing, they'™re stealing all of the fish from the commercial fishermen, and they'™re attracting great white sharks and now it'™s not safe to go swimming," he added. "Certain portions of the population are convinced that seals represent the end of life as we know it.'"

They definitely have attracted sharks. The increase in great white sharks in the waters off Massachusetts in recent years has spurred the the Atlantic White Shark Conservancy and Massachusetts Marine Fisheries staff to collaborate on a study of sharks in the area.

"They’ve been not only tagging sharks, but also identifying the different sharks, say if a shark has a scar or a particularly shaped tail, then they identify it," Chief Reynolds said. "I know there are over 300 individual sharks that have been identified. Last year, there were 133 great white sharks tagged, and over the past four or five years, they see an increase in the shark population in the months, of August, September, October.

“Typically in July and August we see a lot more seals in the area, and the seals are coming closer to shore and the great white sharks eat the seals," she added. "We also have people on the beaches."

Seals, sharks, and people can all come into a dangerous convergence, particularly at high tide, when the deeper water allows seals to come closer to shore and the sharks follow them in, Chief Reynolds explained.

“Since we’ve been educating the public to stay close to shore, to stay away from the seals, in general the visiting public in summer they follow our advice," she replied when asked whether the shark sightings have kept people on the sand and out of the water. "And if they’re at our lifeguarded beaches, our lifeguards keep them close to shore. Keep them safe from the rip tides, because even though there are a lot of sharks and a lot of seals and you’re hearing a lot about it now, our lifeguards are most busy with rescuing people from rip currents, shorebreaks and strong currents.

“But the lifeguards are very proactive, especially at high tide when the sharks can get closer to shore, keeping people super close to shore. And, luckily, the public is staying close to shore.”

If you're still planning to visit Cape Cod National Seashore this summer or early fall, you can prepare for your visit by watching the seashore's shark safety video, attending interpretive programs that explain why there are more sharks in the water at this time of year, paying attention to warning signs at the beach, and downloading the "Sharktivity" app onto your smartphone.

Sharktivity lets you see shark activity around Cape Cod for the past two days, the past week, the past month, and the past year. Touch one of the shark icons on the screen and you'll see information for the date and time the shark was spotted. You also can choose from a select number of named sharks -- Amy, Cool Beans, Flash, Hunter, Jack, Jenna, Luke, Miss Carolina, and some others -- to see if they're in the area.

From the app's menu you also can see the latest shark alerts and even report a sighting.

"Over the past five years, Cape Cod National Seashore, Atlantic White Shark Conservancy, and Mass Marine Fisheries and some of the Cape towns have been really working hard to educate ourselves and the public on how to be ‘shark smart,'" said Chief Reynolds. "We’ve done an incredible job educating ourselves and the public, anything from signage at the beach, to our webpage to a shark video, to Sharktivity, which is the app. If you don’t have it on your phone you should have it.

“We upload all our shark sightings, note if we close our waters to swimming at our various beaches," she explained. "So that’s like real time; 'We’re closed, we’re closed for an hour.’'"

As I was writing this story Saturday afternoon, with the app open on my phone, a shark sighting flashed up as a red exclamation point at about 12:45 p.m.: "Shark spotted by CCNS staff 30 yards off shore south of our beach in front of Town of Truro beach. Swimming closed for one hour." Surrounding the exclamation point were icons representing shark sightings in the past two days.

Shark sighting at Cape Cod National Seashore/August 18, 2018 Sharktivity

While shark attacks certainly gain a lot of attention, the odds of being attacked remain small, though swimming in waters with an atypical high number of sharks in the area will heighten those odds. According to a recent Forbes magazine article, surfers in Hawaii have a one-in-200,000 chance of being bitten by a shark.

"In the United States overall, your risk is just 1-in-11.5 million if you go to the beach, but those odds are overall," the author pointed out.

What are your odds of being attacked by a bear in Yellowstone National Park? About one in 2.7 million, though they go up to about 1-in-232,000 per day if you spend time hiking or backpacking in the park's backcountry, the article noted.

If your plans to visit Cape Cod are set (as mine are), you can improve your odds of avoiding sharks by loading Sharktivity on your phone so you know where the sharks are swimming, avoiding swimming when you can see either sharks or seals in the water, paying close attention to beach lifeguards, simply staying out of the water, or going in no deeper than knee high.

Finally, take a whale watching trip out of Provincetown and you might get to see a great white from the safety of the deck.