An aggregation of right whales in the western portion of Cape Cod Bay has prompted the Division of Marine Fisheries (MarineFisheries) to issue an advisory to all vessel operators. Vessel operators are advised to reduce speed (as slow as 12 knots), post lookouts, and proceed with caution to avoid colliding with this highly endangered whale. On April 22, the MarineFisheries/Center for Coastal Studies (CCS) aerial survey team first reported an aggregation of 10 right whales sub-surface feeding in the western margin of the bay. A bay-wide habitat sampling cruise on April 24 confirmed that plankton patches in this area are stable and extensive. The habitat sampling cruise also confirmed that plankton densities around Race Point are still high enough to support feeding right whales. Last week, an advisory was issued for this area due to an aggregation of 27 feeding right whales. The plankton resources off Race Point and in the western portion of Cape Cod Bay are high enough to support right whale feeding, aggregation, and residency. It is recommended that ships transiting between Cape Cod Canal and Boston use extreme caution. When right whales depart the area, the advisory will be lifted.

Whales that are sub-surface feeding on dense blooms of plankton (copepods) are notoriously difficult to detect. Scientists believe feeding right whales may be oblivious to their surroundings, thereby unable to avoid an oncoming vessel. Sub-surface feeding right whales are particularly vulnerable to ship strikes. More vessel traffic is expected in this area over the next few weeks with seasonal increases in recreational and commercial fishing, as well as whale watching, and passenger ship activity. Right whales are the most endangered of the large whales in the western Atlantic Ocean, with a population of only about 350 animals. Ship strikes are believed to be the primary cause of human-induced mortality to the right whale. Vessels are prohibited by state and federal regulations 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. The last known ship strike in waters near Massachusetts occurred in April 1999 when a sixty ton, female right whale nick-named “Stacatto” was discovered dead in eastern Cape Cod Bay. Dissection and subsequent necropsy revealed a broken jaw and five broken vertebrae suggesting ship-strike as the cause of death.

Management of maritime activities near right whales is part of the MarineFisheries Right Whale Conservation Program. The Right Whale Conservation Program is a cooperative effort between MarineFisheries biologists and CCS to study and protect right whales in Cape Cod Bay. Cape Cod Bay is one of only five known critical habitats for northern right whales, with typically 1/3 of the population utilizing the bay throughout the late winter and early spring. They usually depart the bay by the end of the April for other habitats, notably the Great South Channel Critical Habitat and Bay of Fundy Real-time monitoring of right whales through vessel and aerial–based surveillance, and forecasting of right whale presence through habitat analysis, makes the Massachusetts Right Whale Conservation Program the most comprehensive of any program throughout the species’ range. The presence of whales is also being monitored by Cornell University researchers who use autonomous buoys rigged with hydrophones to listen for the presence of whales around the clock. Right whale “call” counts are communicated back to Cornell and shared with researchers, vessel operators, and fishery managers. Support for the Conservation Program is granted from NOAA Fisheries, the National Fish & Wildlife Foundation., and the Massachusetts Environmental Trust.

The National Marine Fisheries Service (NOAA Fisheries) has been issuing warnings to mariners and others via the Northern Right Whale Sighting Advisory System (SAS). Participating agencies in the SAS include the Commonwealth’s MarineFisheries and Office of Environmental Law Enforcement, the U.S. Coast Guard, the U.S. Army Corps of Engineers (ACOE), CCS, and other research groups. Advisories can be viewed at the NOAA Fisheries Northeast Region web site (www.nero.noaa.gov/ro/doc/whale.htm) and are broadcast over NOAA weather radio (http:// 205.156.54.206/nwr/).

For more information, visit the MarineFisheries website at www.mass.gov/marinefisheries or contact Erin Burke or Dan McKiernan. Center for Coastal Studies (www.coastal studies.org) right whale researchers Dr. Charles (Stormy) Mayo and Dr. Nathalie Jaquet can be reached at (508) 487-3623.