Dr. Gregory Skomal is a Marion resident and internationally recognized expert on white sharks. His research is primarily funded by the Massachusetts Division of Marine Fisheries and associated with the Atlantic White Shark Conservancy, Fisheries and Oceans Canada, and the State of New Hampshire to name a few.
You’ve probably seen Skomal on TV talking about his work studying the behavior of white sharks off the eastern seaboard during National Geographic’s Shark Week blitz. You may even have had the opportunity to hear him speak over the course of the last three years at one of his local presentations hosted by the Sippican Lands Trust. On July 20, Skomal once again gave a riveting update on his ongoing work studying the behaviors of the top, or as he says, “apex” predators in the ocean, the Atlantic great white shark.
It is now well understood why the sharks have returned to the northeastern Atlantic waters – seal populations have exploded. “In 1972, grey seals were near extinction,” Skomal reminded the virtual audience. The U.S. government sought to protect and restore seal populations, and those efforts paid off. “Fifty years later, the population has recovered and repopulated,” he explained. Several seal species have returned in vast numbers to their historic breeding and feeding areas – the northern Atlantic Ocean.
Skomal sketched out the history of white sharks, reminding us that sharks have always been our saltwater neighbors. “In 1985, a shark population study showed that while sharks were as far north as Newfoundland, they weren’t there in great numbers.” But he reiterated that these northern locations are, in fact, among the shark’s migratory feeding locations.
A graph showed that recent study of white shark movement finds the top predator is trolling the outer banks of the Cape Cod peninsula in numbers that humans may find shocking, but researchers find normal. White sharks have also been found in pockets along the shores of Plymouth and several locations on the inner shoals of Cape Cod Bay.
But how are the sharks monitored? How are scientists collecting the data, and to what end game will the data serve human populations? Those were the primary topics of Skomal’s talk.
Skomal wants to answer such questions as to where, when, and how sharks feed on seals. To answer those questions, he said researchers have to observe behavior directly and indirectly to look for patterns – in technical terms, “environmental correlates.” Once the behavior is well understood, the next step is to understand the patterns and the patterns’ predictability in an effort to provide solid forecasting of shark movements along the coast. By answering these questions, Skomal believes public safety will be better served.
To study the animal in its watery habitat, Skomal said tagging sharks with various types of tracking devices is paramount. Currently in use are acoustic telemetry (179 of these tags have been placed on sharks to date), board-scale array (100 in use), and fine-scale array (55 in use). Another type of data collecting tag is the short-term, pop-up satellite tag, behavior tag, and fixed station aerial cameras. Between 2009 and 2020, 230 sharks provided tracking data.
That data has proven that the outer banks of Cape Cod are the primary feeding ground for the apex predator, putting the wild animal and human activity on a collision course.
“Until 2012, there had only been one reported shark attack in the northeast,” Skomal said. That was the 1936 fatal attack that took place in Mattapoisett. The victim was Joseph Troy, Jr. Locals have stated that Troy could have survived that attack, but first aid and emergency services at that time were far from what we enjoy today. Troy died of massive blood loss.
In 2012, 2014, and 2017, three incidents in and around Wellfleet found humans having a “negative interaction” with white sharks, Skomal stated. Then, in 2018, a fatal interaction took place.
“I never anticipated I’d be studying sharks; but, due to these attacks, my focus shifted to predator-prey relationships,” Skomal shared. His research has proven that sharks are using a deep trench near Head of the Meadow Beach in Truro to search for seals in their cat-and-mouse, predator-versus-prey, real-life dramas. It might be interesting to note here that sharks do not eat every day but may feed only several times over the course of a month.
Skomal said some of the tracking devices can provide immediate information that a shark is close to shore. Real-time trackers and receivers can alert lifeguards on beaches to get swimmers out of the water. But, he said, while those safety efforts can avert a tragedy or negative interaction between human and shark, “Not all sharks are tagged.” He said there is a study taking place now to try and determine the number of white sharks in the cape area during the height of the season.
Skomal also shed a bit of light on the realities of being a white shark just trying to earn a living. “If a seal sees the shark, the shark loses,” he said. Seals can outmaneuver a shark. He said that sharks do come in close to shore because “the seals aren’t stupid; they know the shark probably won’t chase them into shore.” But every now and then, a daring shark will do just that and win. The most successful hunting technique is an attack from below; hence, sharks in an underwater trench shouldn’t be surprising.
Sharks migrate and feed around Cape Cod between June and November with their greatest numbers being here in August through October, said Skomal. “We are beginning to understand the shark’s movements because of the data collected.”
There was good news for Buzzards Bay and those that recreate in those waters: While great white sharks are nearby, they seem to just pass by the opening of Buzzards Bay on their way to better hunting grounds, the cape’s outer banks and Nantucket Sound.
What we know today: Sharks migrate from the southern eastern seaboard north as far as the Canadian Maritimes in a historic migratory pattern. Over the course of 50 years of protection, seal populations have increased, drawing more apex predators to the area. Researchers are using a variety of tracking devices to study shark movements and feeding habits in an effort to not only better understand the animal but to help humans stay out of the way, avoiding negative interaction and living more harmoniously with great white sharks. And, last but not least, more study and more data are needed to build a more complete understanding of these magnificent predators of the sea.
Skomal says research and tagging efforts are currently scheduled to continue through 2023.
Sippican Lands Trust will announce its next event in the virtual speaker series this month. The attendance cost via Zoom is $10 for members and $20 for non-members, and benefits the SLT’s land conservation efforts.
By Marilou Newell