Animal apparently lived
7-10 days with
a fractured jaw
NMFS Northeast Region
N E W SGloucester, Mass. -- Scientists have determined that a female right whale found floating dead in Cape Cod Bay in April died from injuries most likely sustained when she was hit by a ship. The whale apparently lived at least a week after a collision that broke her jaw but appears to have died from problems that arose from that injury, according to a final necropsy report Dr. David St. Aubin filed this week with the NOAA's National Marine Fisheries Service (NMFS).
"The animal was observed swimming, apparently normally, some days after she is presumed to have sustained the jaw fracture," said St. Aubin, a Mystic Aquarium whale expert who led a multi-institutional necropsy team." But her health was compromised by the injury, and she appears to have developed metabolic problems — septicemia, blood clotting, and circulatory failure that resulted in her death." (Septicemia is blood poisoning caused by infection.)
The necropsy team concluded that the animal must have survived the initial injury because lab studies revealed a cellular response to the fractured jaw, including the growth of new cartilage that normally takes 7-10 days. There was also evidence on the left pectoral flipper of a healing process that requires a week or more, according to the report filed by St. Aubin, Dr. Michael Moore of the Woods Hole Oceanographic Institution, and Dr. Sylvain De Guise of the University of Connecticut.
The 45-foot, 60-ton animal was discovered April 20 floating dead in Cape Cod Bay by a whale survey team from the Massachusetts Division of Marine Fisheries. The whale, nicknamed "Staccato," had been observed on nine occasions between January 17 and April 15 this year. Her behavior appeared normal when she was last seen alive April 15.
The animal was towed to a Wellfleet beach April 21 where St. Aubin led a team of more than 40 scientists and students in a three day necropsy. The team on the beach discovered the animal's broken jaw and five broken vertebrae.
The necropsy report presents three possible explanations for the broken vertebrae. Those fractures could have occurred at the same time as the jaw fracture. The animal may have been hit by a second ship shortly before it died. Or the vertebrae could have been fractured during the necropsy.
"The source and timing of the vertebral fractures will remain a matter of speculation," St. Aubin concluded. He added, however, that uncertainty about the cause and timing of the vertebral fractures does not alter the primary finding that the whale appears to have died from injuries sustained in a ship collision 7-10 days earlier.
North Atlantic right whales are one of the most highly endangered large animals on earth, with a total population of approximately 300 animals. Since 1991, between one and two right whales per year are known to have been killed or seriously injured by ships. To help reduce the risk of collision, the federal government this year established a mandatory ship reporting system that requires large commercial vessels to call-in before they enter right whale critical habitat areas. Ships that call-in receive the latest information about right whale sightings and whale avoidance procedures.
NOAA Fisheries, the federal agency responsible for living marine resources, coordinated the response to the right whale's death. NOAA Fisheries enforcement agents are conducting an investigation and have asked that anyone with information about a possible ship strike in early-to-mid April call a toll-free hotline, at 1-800-853-1964.
St. Aubin worked with scientists from the New England Aquarium, Mystic Aquarium, the Center for Coastal Studies, the Cape Cod Stranding Network, the Woods Hole Oceanographic Institution, and the National Marine Fisheries Services. Laboratory studies of tissue samples were conducted at the University of Connecticut and the Armed Forces Institute of Pathology in Washington, D.C.