"The sharks and the humans are both on the water's edge more frequently in the summer," said Dr. Nick Whitney, senior scientist at the New England Aquarium.

Here's what's open and what's closed on Cape Cod this Fourth of July. Most grocery stores are open on July 4. For example, Stop & Shop is open on the Fourth of July, according to its website, as is Market Basket, which is open on July 4 from 7 a.m. to 9 p.m., the website says.