Swimming has been banned in some areas around Nantucket Island, Massachusetts , after five seals were attacked and killed by great white sharks near the shore, per the Nantucket Current . One of these attacks in which a seal was bitten in half was captured on video.

Officials with The Trustees of Reservations, a nonprofit organization committed to protecting the regional environment, and the U.S. Fish and Wildlife Service have prohibited swimming along Great Point and the Nantucket National Wildlife Refuge, per NBC News .

This is not a decision weve made lightly, Sarah Cassell, managing director of marketing and communications at the Trustees, told the outlet Tuesday.

Visitor safety is our utmost concern, especially given the remote location of this beach should a serious incident occur, she continued. Well continue to monitor shark activity in partnership with the U.S. Fish and Wildlife Service.

An aerial survey Tuesday spotted nine great whites in the waters, with footage from locals like Nick Gault capturing even more particularly the seal being dismembered .

Diane Lang, stewardship manager of the local Trustees, told the Current that, while residents are aware of the dangers of swimming in that area, tourists decidedly arent.

We saw people jumping in the water over the Fourth of July, Lang said. We have visitors come out and theyre naive to their surroundings.