On a recent trip to Cape Cod, Massachusetts, I was shocked by a headline in the local paper. On the front page, above the fold, it said, “Great Whites may be expanding their turf” in huge letters. Sharks were never an issue in the area when I vacationed there as a child, so I was interested to find out more about this hypothesis and why it was being put forward.
Apparently, during the second week in October, a great white shark was tracked in Wellfleet Harbor for two days before swimming towards Cape Cod bay. The tagged shark, named Katharine, is a 2,300 pound great white that has been tracked since August of 2013. During that time, Katharine has traveled more than 8,000 miles. The tracking device has been followed by the research vessel, Ocearch.
During her time near the Cape, the device “pinged” her location as close to the town pier as well as near Great Island. Despite the margin for error in the device, the research team believes that the data is conclusive that it very likely that Katherine was at the harbor.
Throughout the summer of 2014, the team identified 56 great whites in the Cape Cod area, and tagged 15 of them. This was part of a study of the sharks that migrate to the area to eat seals each year. The movement of Katherine into the Bay may be indicative of overcrowding of the usual hunting grounds and could result in sharks moving north towards the Bay in search of food. There have been other bay sightings, but this is the first tagged shark in the area.
Seals are attracted to Monomoy as well as Jeremy Point and Wellfleet harbor. Thousands are seen on the rocks in the sun. The natural order of things is that the sharks follow the seals. With more seals arriving near the bay, more shark sightings are bound to occur.
Katherine took a straight path from the middle of September off of the North Carolina shore to the Nantucket area, arriving September 27. She stopped in Monomoy, where the gray seal population is largest, and swam on. Just a short while later, she was off of Marconi Beach in Wellfleet to Provincetown and on to the bay side of Welfleet.
As more sharks arrive in the area, they get more daring and roam closer to shore in search of food. Researchers tag some of the sharks and have recently begun using underwater video techniques to note identifying marks such as scars, bites, and deformities from altercations with other sharks. They hope to use the data to estimate the average number of sharks that travel to the waters along Cape Cod and document any changes in the population. Some may be simply staying throughout the summer rather than feeding on seals and moving on.
Aside from Katherine, a pilot spotted four other sharks swimming near the bay. Beach Administrator Suzanne Thomas would like to use a system of buoys to alert beachgoers of tagged sharks in the area during beach season. The buoys would need to be equipped to respond to the tags.
Only ongoing research and time will tell whether great whites are moving…and staying…around the Cape.
