On April 14, approximately 25 to 30 right whales were spotted 500 yards off the coast of Provincetown.  DFG’s Division of Marine Fisheries issued a high risk advisory due to the number of whales, their behavior, their proximity to shore and the local abundance of zooplankton – tiny marine creatures on which the whales feed.  An aerial survey will be performed over the next few days to fully ascertain the number of whales in the area. Right whales gather annually in the waters off of Cape Cod to feed. Last March and April, DMF counted close to 70 whales.

Right whales are the most endangered large whale in the North Atlantic, with a population of approximately 450 animals. Adult right whales average from 45 to 55 feet in length and can weigh up to seventy tons – the largest measured specimens have been measured at 60 feet long, weighing 117 tons. Females are larger than males.

Right whales engage in surface and subsurface feeding and are often difficult to see, putting them at great risk to be struck by vessels. Vessel strike is a major cause of human-induced mortality for right whales.  For the safety of both mariners and whales, vessel operators in the Cape Cod Bay area are strongly urged to proceed with caution, reduce speed (less than 10 knots), and post lookouts to avoid colliding with these highly endangered whales.

Highly concentrated amounts of zooplankton at and just below the surface are driving the whales’ behavior. Based on a survey of zooplankton performed on April 14, it is expected that this aggregation of whales will persist for several more days to perhaps a week. DMF will lift the advisory when the right whales depart the area.

Vessels are prohibited by state and federal law from approaching within 500 yards of a right whale. Massachusetts Environmental Police and U.S. 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.

Management of maritime activities near right whales is part of the DMF Right Whale Conservation Program. The Right Whale Conservation Program is a cooperative effort between DMF, the Provincetown Center for Coastal Studies (CCS), and the National Marine Fisheries Service to study and protect right whales in Cape Cod Bay.

Please report all sightings of right whales immediately. Call the NOAA Fisheries Hotline at 866-755-NOAA (or hail the Coast Guard on Channel 16) and for more information, visit the DMF website at www.mass.gov/marinefisheries.