I seem to remember from reading Jaws the book that in response to a question about why the shark was hanging around, a character replied “It had food”.
Seal thriving is now throughout New England, thanks to Federal protection.
Data shows some white sharks hang around Cape Cod, others cruise the coast all the way up into Canada. Plenty of seal meal opportunities along the way.
Right now, as best I can determine, if the seal meal is readily available, about once a week is adequate to feed a white sharks appetite. -Tom