A total of 161 great white sharks have been spotted off the coast of Cape Cod, Massachusetts, since June. Experts say attacks on people are unlikely as the sharks are looking for seals.

The odds of an attack are low, experts say, yet their advice today is not to go into the ocean above your waist. Are our carefree swimming days over?

A new study has documented unexpected consequences following the decline of great white sharks from an area off South Africa. The study found that the disappearance of great whites has led to the emergence of sevengill sharks, a top predator from a different habitat. A living fossil, sevengill sharks closely resemble relatives from the Jurassic period, unique for having seven gills instead of the typical five in most other sharks.

There’s only one historical record of a great white shark in the Bering Sea: fishermen caught one nearly 40 years ago. But scientists have reason to believe that in recent years there might be more of the predators around.