Massachusetts state officials are warning boaters to watch out for North Atlantic right whales in the western part of Cape Cod Bay, after about 60 were seen last weekend.
Vessel strikes are a major cause of death for right whales, of which only 550 are said to exist. Right whales are the most endangered large whale in the North Atlantic.
Vessels are also prohibited by state and federal law from approaching within 500 yards of a right whale. Massachusetts Environmental Police and Coast Guard are authorized to enforce the 500- yard rule. Vessels that find themselves within 500 yards of a right whale should slowly and cautiously exit the area.
The state Division of Marine Fisheries issued the high-risk advisory because of the number of whales, their behavior and closeness to the shore and the local abundance of zooplankton, which they feed on.