I don't think there used to be Great White sharks off of Cape Cod, but there have been the last couple years, and they're coming back this year.

What researchers don't know are how many great white sharks there are, both in local waters in the summer, and along the East Coast. That number could be important since great whites generally don't feed for a month after dining on a seal, Skomal said.

This is great news if you like sharks. It's bad news if you're part of the seal colony of Monomoy Island or, well, me.