Sharks: Our Other Visitors
by: Joshua H. Balling
Last August, Doug Lindley had just taken off from Nantucket Memorial Airport on his way to New Bedford to get some engine work done on his plane when he spotted a pair of white sharks off Cisco Beach. He radioed in, and word was sent to the lifeguards to clear the water and close several beaches until the sharks had left the area.
“You can see the fish from the air pretty clearly. It is kind of hard to tell without a surfer or a seagull or something in the area to compare, but one of them was probably a 10-footer,” said Lindley, who often flies as a spotter for sport fishermen. One of the sharks was about 10 feet off the beach and the other just beyond the surf break.
“We see them more often off the eastern side of the island, later in the fall. One thing I have noticed is they seem to be in the areas where the seals hang out and feed, and that’s where the surfers are, too. The surfers don’t seem too bothered, though. I think the sharks know the difference between chewing on a wetsuit and chewing on a seal.”
Sharks are a fact of life in our waters. In recent years, the number of white-shark sightings in the region has been on the rise, most off outer Cape Cod, but several north and east of the island, and even off the south shore. Lifeguards closed Nantucket beaches on two occasions last summer due to confirmed shark sightings, and surfers this May and June reported seeing sharks attack seals off Tom Nevers and Nobadeer.
Seals, the attraction
There is no disagreement that an abundant supply of food – in this case the grey seal – is attracting the white shark to the waters off the Cape and Islands.
Through the 20th century, seal populations remained low in the western North Atlantic. It wasn’t until their hunting and killing was outlawed in Massachusetts in the 1960s and in the entire country in 1972, via the Marine Mammal Protection Act, that they began to repopulate the region. With the resurgence of seal numbers, white sharks have returned to the waters thanks to the steady food supply.
They are also rebounding after almost being wiped out by overfishing. White sharks were designated a protected species in most federal waters in 1997 and in Massachusetts waters in 2005.
White sharks, made famous by “Jaws,” written by island summer resident Peter Benchley in 1974, are migratory animals, spending their winters in warmer waters from the Carolinas into Florida and the Caribbean, before making the long journey north into the Gulf of Maine and even Canadian waters, said Greg Skomal, a Ph.D. marine biologist with the state Division of Marine Fisheries and head of the Massachusetts Shark Research Project.
Skomal has dedicated his career to studying sharks, tagging and releasing them to learn more about their movements, behavior and population size.
“It’s remarkable how much variability you see in the species, though,” he said. “The sharks return each year, but not all of them, and some only stay a few days and move on. Some stay the whole summer. It’s challenging for scientists to come up with general patterns, since not all of them repeat from year to year.”
The majority of white-shark reports off Nantucket are on the northeast side of the island, near Great Point, with its high concentration of seals and deeper water. Those occasionally spotted off the south shore are “just passing through,” Skomal said, and unlikely to navigate through the shoals into the shallow water off the beach where most swimmers are.
”By all accounts, the sharks that we have been studying move along the south sides of Martha’s Vineyard and Nantucket as they creep up into the Gulf of Maine. They don’t appear to indicate any level of residency in doing that. They’re not here to eat people. It’s more of a highway. They’re just moving through, generally a quarter-mile or more off the beach,” he said.
They also tend to avoid areas where they may end up on the beach, or have to expend too much energy in search of a meal, Skomal said. The shallow water and swift currents along the south shore generally mean it’s not worth their while.
“These are big animals, and to move into very shallow water, that’s physiologically challenging. They just don’t want to end up on the beach,” Skomal said. “It’s a net loss of energy, forever fighting the currents. You see it along the eastern edge of Cape Cod, but the seals there are in such numbers it’s worth the risk for them.”
The majority of white-shark activity tends to be north of the island off the outer Cape, and it will likely continue, Skomal said. The conditions there are more conducive for the apex predators to easily feast on the abundance of seals off Monomoy Island, and in Eastham and Truro, where deep water is just off the beach.
“It’s the consistent supply of potential food. There are big aggregations of seals that haul out on the Outer Cape. The water temperature is cooler and the access is easier,” he said.
The relative explosion in the seal population since federal protections were enacted nearly 50 years ago has, in essence, created a “seal restaurant” in Cape and Islands waters, Skomal said.
Nantucket charter fisherman Bobby DeCosta agreed, and said he’d like to see greater efforts made to get a true count of the grey-seal population and possibly introduce a management program if it is as great as most fishermen and many scientists think it is.
“There’s no way in hell I’d get in the water between Monomoy and Provincetown or Eastham. That’s just asking for trouble,” said DeCosta, who has seen a white shark attack a seal in the shallows off Great Point and take a bluefish right off an angler’s line.
“I’ve listened to the spotter guys who tag these things. They see them every time they fly. They see dozens of them.”
“I’m not saying we should go out and kill every seal, but we can’t continue to let one population go unchecked,” DeCosta continued.
“You can’t even go 100 feet down the beach right now along any section of the sound, without seeing two or three seals. There are tons of them at Great Point, they’re at Smith’s Point, they’re on the south shore.”
Maintaining the balance
White sharks are not only essential to keeping the seal population in check, but maintaining ecological balance, said Blair Perkins, who runs Shearwater Excursions, a Nantucket-based whale-watching and ecotour business.
“As with any apex predator – wolves, coyotes, sharks – their job is to reduce the number of other animals so they don’t overpopulate. White sharks are fish-eaters until they are eight to 10 feet long, then they eat marine mammals,” Perkins said.
“White sharks eat fish which prey on other fish, and with a lot of seals around, you need something to take them out, to balance everything. If you got rid of all the sharks, you’d see an enormous increase in some fish, which would eat all the other fish, the smaller fish like mackerel, and you’d get huge algae blooms.”
Fear – and Fascination
Sharks have occupied news stories and imaginations on Nantucket since long before Benchley penned “Jaws” and Steven Spielberg turned it into a movie that in its opening weekend had audiences fleeing the theaters.
A Pittsburgh journalist visiting the island in 1922 wrote about shark fishing upon his return home, noting that shark skin made fine leather. Two decades earlier, Nantucketers were discussing whether shark meat should be considered a delicacy.
“Everyone connected with the fish establishments is being asked this question innumerable times this summer just past, as a large number of sharks were brought to the fish market ready for sale,” read a story in The Inquirer and Mirror.
A 1902 letter to the editor asked if there was really such a thing as a man-eating shark, or if that was just a myth.
There’s always been something mythical about sharks, Skomal said.
“They’re top predators, these mysterious things living in the ocean, and every now and then, rarely, they hurt us, they bite us. It’s innately in us to be concerned in terms of survival and the evolution of survival over long periods of time. Sharks create this broad spectrum of emotions that ranges from absolute terror and fear to fascination in every one of us,” he said.
“Some people outgrow it. Others, it stays within them. We tend to attribute a lot to the movie ‘Jaws,’ which certainly tapped in to the fear, but the fascination has persisted for years. Fortunately, public attitudes seem to be shifting slowly when it comes to sharks. The balance now seems to be moving from fear to fascination and respect.”
Denizens of the deep
While white sharks garner the majority of the attention these days, several other species of sharks are far more common both on and offshore around Nantucket. Smooth and spiny dogfish are frequently brought up on fishing lines. Dusky sharks and sand tiger sharks also call the coastal waters off Nantucket home. Several, like sandbar sharks, are essentially harmless to humans, and not all are protected.
The Nantucket Shark Tournament run by the Anglers’ Club for years awarded prizes for the largest porbeagle, mako and thresher sharks caught in the waters 30 miles or more to the south and east of the island.
“There are really three species of shark we catch here: blue, mako and thresher,” DeCosta said. “It’s mostly porbeagles to the east, and makos and threshers to the south. The thresher has that big tail, which it uses to stun its food. It has a small mouth and small teeth. I don’t think I’ve ever heard of a thresher attacking a human.”
While there have been no recent interactions between white sharks and swimmers or surfers on Nantucket, there have on Cape Cod. In September 2018, a Revere man was killed by a white shark while bodyboarding off Wellfleet. A month earlier, a New York man survived a white-shark attack off Truro.
Nantucket officials are paying attention to what’s happening to the north, and have adopted a shark-sighting policy that calls for the water to be cleared for two hours inside a swim zone and one hour outside following a confirmed sighting.
“If there’s a spotter plane nearby, we ask them to come and take a look before we open back up,” harbormaster Sheila Lucey said. “We have our all-terrain vehicle guys cruise the adjacent beaches to get an idea of the way it was going.”
Signage is posted at many beaches, as well as the access to Great Point, warning of the possible presence of sharks. The signs, however, have a habit of disappearing, Lucey said.
“We train and prepare our lifeguards for a shark bite. All of them have ‘stop-the-bleed’ training, and there are stop-the-bleed kits with tourniquets on the lifeguard stands and in our all-terrain vehicles. We are as prepared as we possibly can be, and have policies in place to act quickly when we have to.”
The likelihood of being attacked by a white shark is incredibly low, Skomal said.
“You have to think about what the real probability is. We’ve all heard the analogies. You’re more likely to get hurt driving to the beach,” he said.
“Riptides and currents have killed a lot more people than sharks ever will. The best advice is, know where you are swimming. If you see a density of seals in the area, compatible with an area white sharks are likely to get into, the potential for white sharks is there. We’ve been telling folks on the Outer Cape that if they’re concerned, don’t go in beyond your waist.”
Still in the discussion stage on the Cape are more concrete measures, like stringing anti-shark netting around popular beaches similar to what has been done for decades in Australia and South Africa, and installing more sensors in the water to detect the presence of white sharks. Lucey and other Nantucket officials have been part of those discussions.
Perkins believes they are worth considering.
“Humans have always been reactive instead of proactive. I see no reason why officials shouldn’t be designating swim areas with possible nets there. They are things that work. That stuff should be considered. Education is key, being proactive is key,” he said.
“I think sharks will continue to increase because the food source is there. They are
filling back into areas where they have not been seen in decades. We are terrestrial animals. They are aquatic animals. We are in their habitat, we are in their environment. We don’t belong there. Unfortunately, there is going to be a time here on Nantucket, it will probably happen, that there will be an attack. It is just the harsh reality.”
A better understanding
Meanwhile, work continues to better understand sharks, white sharks in particular, though Skomal’s research, and that of others, like OCEARCH, a nonprofit group that has tagged 44 North Atlantic white sharks since it first began hoisting them aboard its 126-foot modified Alaskan crab boat in 2012. The most recent off Nantucket was a 12-foot female tagged last August. The radio tags can be tracked online.
In addition to tagging each shark three times, OCEARCH takes blood, mucous and tissue samples to perform 17 other tests after the animal is released back into the water.
Skomal’s most recent work has taken a closer look at predatorprey behavior.
“Frankly, it’s driven by public-safety concerns. We’re getting a real strong sense of behavioral patterns relative to sharks and seals that will hopefully allow us to forecast areas that might or might not be prone to the presence of these animals when they are feeding. It could be very helpful,” he said.
Sharks are even being caught and tagged off the beach.
Elliot Sudal has reeled in, tagged and released more than 150 sharks on Nantucket over the past six years. In 2013 he was fishing in Sconset when a photo was taken of him pulling a sandbar shark on-shore by its tail before releasing it back into the surf. It wasn’t long before his story went national. CNN, “Good Morning America” and “Fox and Friends” all ran pieces about him. After the photo and story went viral, picked up by news organizations from Canada to Japan, the National Oceanic and At-
mospheric Administration asked him to participate in its Apex Predator Tagging Program, which has existed for over 50 years, and tagged over a quarter-million sharks to date.
Sudal, who has a degree in environmental science and biology from Central Connecticut State College and has worked with the U.S. Fish & Wildlife Department in Connecticut and the U.S. Department of Environmental Protection, releases all the sharks he catches from the shore. His methods, however, still draw criticism. Sudal said he takes precautions to ensure the survivability of the sharks, using circle hooks for easier removal and limiting the time the sharks are out of the water to under a minute.
Some, however, like Perkins, call it inhumane. DeCosta, on the other hand, believes he’s doing valuable work.
“There are some people who think he’s a menace to the shark population, but he’s tagging them. Very little is known about brown sharks and sandbar sharks. What he’s doing is a big help,” he said.
In the end, the equilibrium needs to be maintained between all ocean dwellers and man, Perkins said.
“We’re just part of the food chain. I point out on my tours that the typical food-web picture is a pyramid with man on top. That couldn’t be further from the truth. It’s really one big circle and we are somewhere in the middle,” he said. ///
Joshua Balling is associate editor of Nantucket Today and managing editor of The Inquirer and Mirror, Nantucket’s newspaper since 1821.