For many, the idea of living with sharks is a fairly new phenomenon. After all, sharks like warm water – right? Sharks are not that common around the northeast – right? Most sharks stay in tropical locations – right? Wrong! Spend a little time with well-known and highly-respected shark expert Dr. Greg Skomal, and you’ll soon have all your long-held misconceptions about sharks, especially the great white variety, dispelled.
Skomal, a Sippican Lands Trust director, was hosted as guest speaker on August 11 by the SLT via remote access. The event gave attendees an opportunity to follow Skomal as he tagged great white sharks around the Cape Cod peninsula and to learn more about his decades-long pursuit in understanding one of the ocean’s greatest hunters.
Skomal’s research in understanding the white sharks’ habits of daily living is thrilling to hear about from the man himself and entertaining as evidenced in his frequent appearances on National Geographic’s Discovery programs. His ability to plain-speak the technicalities of his work grants the layperson insights into the lives of sharks. And who hasn’t thought about sharks especially now when we are all trying to enjoy beaches and swimming?
Skomal began his talk by providing a rather shocking bit of historical data. As far back as the 1800s, great white sharks have been reported and recorded as being in the North Atlantic seas. Records indicate that great white sharks have been found as far north as Newfoundland, he said. Taking written eyewitness accounts and adding to that all other forms of data reporting, including modern satellite technology, Skomal surmised that sharks have always been in the northern seas.
Adding to the historical perceptive, Skomal discussed shark attacks in the northern region, noting the infrequency while acknowledging the slight uptick. “There was a fatality in 1936 off Mattapoisett,” he stated. Calling shark attacks “mistakes on the part of the shark – they don’t hunt humans,” he chronicled non-fatal incidents in 2012, 2014, 2017, two mistakes in 2018 of which one was fatal, and the more-recent 2020 fatal attack of a woman in the Gulf of Maine. He attributed the rising frequency of “mistakes” as a direct result of the rising seal populations in the area. Skomal’s studies over the last 10 years have focused on tagging sharks that frequent the area. The data collected points to predators that are finding an availability of prey.
The first shark was tagged in 1979; today some 200 sharks are wearing sophisticated acoustic tags that are helping scientists around the world come to a better understanding of the wild, underwater master of the hunt. Using computer graphs and modeling Skomal’s research reveals a direct correlation between where seals congregate and where sharks roam. “Cape Cod is like a rest stop on (Interstate) I-95 for some sharks on their north way,” he quipped. But the data as visually displayed told the full story. Data points indicating where seals are located and data points indicating where sharks are present overlap.
Yet humans want what they want, when they want it, and so summer on Cape Cod attracts thousands of humans. The local economy depends on tourism. There have been serious discussions in some lower Cape towns about finding ways of getting rid of the sharks. For Skomal and his team of researchers, finding a way to explain shark movement and activity is a primary goal. With understanding, he believes that the safety of both marine life and human life can be achieved.
“Sharks are in the area in greatest numbers between August and October,” Skomal explained. “They spend their time where the food is plentiful.” This happens not only along the eastern edge of the peninsula (outer Cape from Provincetown to Chatham), but also in a few hot spots along the northern edge, he said.
Skomal said that sharks are not able to react swiftly or catch food easily if one compared the agility of a seal to the cumbersome movements of a great white shark. Thus, sharks need to be where the greatest numbers of prey can be found in order to have any level of hunting success. He said that there is a distinct seasonality to Great White shark movements; mid-summer to early fall when the seal populations are at their peak, the dinner bell rings for the sharks. Once a shark has fed on seal, it might not eat again for two months due to the nutrient-rich blubber the seal contains.
The seals enjoy the beaches where they sun themselves, venturing only a few feet from shore when returning to the water. Guess where the sharks are waiting – that’s right, a few feet from shore, hunting in the shallows. Researchers are hopeful that the data will provide information on times of the day when sharks are most likely to be hunting. Some of that detail has already been collected from tagged sharks. If the data can shed light on when sharks are most likely to be in the area and what time of the day they are hunting, swimmers will be able to make better decisions about when and where – or not – to go into the water, Skomal said.
Skomal’s tagging efforts have paid off in ways that are immediately useful and in ways that will add to the future understanding of the massive fish. One interesting fact, one that has more recently been uncovered via tracking technology, is that sharks are in the Northern Atlantic Sea throughout the winter. Not all great white sharks migrate south. Studies have found that many of those that remain along the continental shelf dive 3,000-feet into the deep where food commonly consumed by sharks is not available. “We don’t really understand what they are doing down there. We are collecting millions of data points,” Skomal said of the ongoing east-coast research.
All along the western (inner) edge of Cape Cod, Skomal’s teams have placed receivers that pick-up tagged sharks if they are in the area. He also had one placed near Mattapoisett. “In three years, not one tagged shark has gone by there,” he shared with a chuckle. Good news for those recreating in Mattapoisett Harbor.
To say marine studies is Skomal’s lifework is a bit of an understatement. The good doctor has been a senior fisheries biologist with the Massachusetts Marine Fisheries since 1987 and currently heads up the Massachusetts Shark Research Program. He is also educating future researchers as an adjunct faculty member at the University of Massachusetts Marine Science and Technology program in New Bedford, an investigator for the Woods Hole Oceanographic Institute, and an adjunct scientist with the Center for Shark Research in Sarasota, Florida. Skomal’s work for the Division of Marine Fisheries has been partly funded by the Atlantic White Shark Conservancy, an organization whose mission is to provide research opportunities, education, and public safety.
To learn more about Dr. Greg Skomal and his work, visit www.atlanticwhiteshark.org, or the Massachusetts Division of Marine Fisheries at mass.gov. You may also be interested in an educational YouTube video geared toward early learners, featuring Skomal, titled “Q/A with Shark Scientist, Dr. Greg Skomal” and produced by the AWSC on April 9, 2020.
By Marilou Newell