With summer fast approaching, the migration of the Atlantic Great White Shark increases daily. How do we know this? Just ask marine biologist, author, professor and reality TV shark expert, the now-famous Dr. Greg Skomal.
On May 20, Skomal gave his annual update on not only the migration of the seas’ great hunter but also the technology employed to better understand Great White Shark behavior.
Skomal has been tracking and tagging the massive ocean migrants for decades, and one thing he knows for sure, in the absence of modern technological devices, his job would be nearly impossible to do. The Great Whites can be elusive, their habits of daily living not fully known.
The doctor’s goals have shifted from the early days of the 1980s when simple trackers were used to note shark movements to the 21st century acoustic telemetry units. From simply gathering data on shark populations to studying their behavior, a much more complex process, the ongoing research keeps Skomal very busy.
“We started with the distribution of sharks along the northeastern U.S. as far north as Newfoundland,” said Skomal, who in those early days studied dead sharks, their stomach contents and reproductive systems, but with technology studying their behavior is now the focus.
“We live in a changing world,” Skomal stated, a world that in the 1970s passed the Marine Mammal Protection Act which included seals, the Great White’s favorite food. “The seals responded and rebounded; the restaurant was opened,” he shared with a chuckle.
Skomal said that Great White Sharks have learned how to hunt close to shore where the seals tend to feel safe. This has caused a collision between an animal on the hunt and a human enjoying the ocean. He provided the incident data: 1936 one fatal shark incident in Mattapoisett; 76 years later (2012) another incident off Truro; then in 2017 and twice in 2018, sharks either challenged recreators or severely injured them including at least one fatality. Clearly, the confluence of sharks and humans needs further study to avoid what could be dangerous for both life forms.
Since 2009, Skomal and his team, which includes a pilot in a spotter plane, have tagged 300 sharks. Twenty-five more sharks are now wearing acoustic devices that are collecting behavioral data such as when and where they hunt. Unfortunately for tourists visiting the outer Cape, they are in not only the migration area of these formidable fish but also in the seals’ favorite place to congregate. People can easily find themselves in the middle of a fight to survive as the Great Whites attack their prey.
Demonstrating the data collection and the plotting of shark migration and hunting patterns, Skomal displayed video and other graphics that clearly showed where the sharks are and how they use sandbars and seafloor valleys to hunt and capture prey – all along the outer Cape Cod area.
Skomal said that, at Newcombe Hollow Beach in Wellfleet, the site of a fatal shark bite in 2018, a live receiver notifies lifeguards when a tagged shark is in the area, giving safety measures a chance to work. And it is this point, safety, for which Skomal is now placing most of his energy. Collecting data and using that data to better inform the public. He is as much concerned for human safety as he is for the safety of the Great White Sharks.
And there is still so much to learn.
Further study is needed to more fully inform Skomal and his team where the sharks are and when they are feeding because “We don’t see many kills except occasionally in shallow areas,” he said. New technology is allowing direct and indirect data to be gathered, but “We don’t know where they breed or give birth.” Skomal said by studying patterns there can then be extrapolated predictability as to Great Whites’ migration, which occurs between May and October with August, September and October the height of their presence on the outer Cape.
Skomal plans to continue his efforts to help the public for safety’s sake and for the future of one of nature’s most fascinating creatures – the Great White Shark.
The presentation was hosted by the Marion Natural History Museum, now celebrating its 150th anniversary. To learn more about programming, visit marionmuseum.org.
Marion Natural History Museum
By Marilou Newell