This Massachusetts Division of Marine Fisheries (MarineFisheries) is reminding all mariners that there is a small vessel (less than 65′ overall) speed limit in Cape Cod Bay to protect endangered right whales from the threat of ship strikes. During the late winter and early spring, right whales migrate into and aggregate in Cape Cod Bay where they feed on abundant zooplankton. As spring progresses, these whales begin feeding close to the surface and become more susceptible to ship strikes. Vessel strikes are a significant source of mortality and serious injury for right whales, even with smaller vessels. However, the lethality of ship strikes is greatly reduced when vessels are operating at speeds of 10 knots or less.
The small vessel speed limit— established in 2019—applies from March 1 – April 30 within those waters of Cape Cod Bay south of 42° 08′ north latitude, as well as those waters north of Cape Cod that are west of 70°10′ west longitude (see map). A complementary federal speed limit applies to all vessels 65′ overall length and greater. DMF may extend or rescind this seasonal small vessel speed limit based on the continued presence or absence of whales.
Aerial surveillance flights by the Center for Coastal Studies and NOAA Fisheries on March 21 and 22, 2023 documented around 80 right whales in Cape Cod Bay and nearby southern Stellwagen Bank. See map below. These whales were feeding at or just below the surface and are extremely difficult to detect from a vessel.
The Division of Marine Fisheries also reminds recreational boaters and commercial fishermen of the state and federal law that prohibits approaching a right whale within 500 yards. For the safety of both mariners and whales, vessel operators in this area are strongly urged to proceed with caution, reduce speed (less than 10 knots), and post lookouts to avoid colliding with this highly endangered whale.
This small vessel speed limit does not apply to emergency and enforcement personnel, including federal whale disentanglement teams. Additionally, small vessel traffic operating within the inshore waters of Plymouth, Duxbury, Kingston, Barnstable and Wellfleet Harbors are exempt.
For more information regarding the management of protected marine species in Massachusetts, please visit our website (www.mass.gov/marinefisheries) or call us at 617-626-1520.