Boston, Mass. — The gravely ill pilot whale that had been swimming erratically and very slowly in Plymouth Harbor since Monday has passed away. Late Thursday afternoon, the young adult female entered shallow water in Plymouth Harbor. There, New England Aquarium staff observed the animal’s exceptionally poor condition and  prepared to euthanize it. A staff veterinarian administered a sedative to relax the animal. Before administering any further euthanasia drugs, the whale mercifully died.

 
Photo via WCVB The Boston Channel


A necropsy by Aquarium staff at their new Marine Animal Care Center in Quincy today (Friday) has revealed that the nearly 11 foot long animal weighed only about 1000 pounds and was very thin. It had no food in its gastro-intestinal (GI) tract. The animal also had a significant parasite problem and had some small barnacles growing in its teeth, which is a likely indicator of prolonged poor health. Extensive tissue samples were taken from most of the animal’s major organs and will be shipped to pathology labs for further diagnosis. Testing normally requires many weeks for results to be returned.

The animal’s skin surface also had heavy abrasions, probably from multiple previous strandings. There was also sand and mud in the GI tract, which is also usually an indicator of past stranding events. This animal, at first sighting on Monday, was suspected of being among three pilot whales that had stranded on Duxbury beach last Monday morning on Columbus Day. Two of those animals were refloated with the incoming high tide and the assistance of a boater. The largest of that group, a 14 foot male, died and was necropsied on the beach by Aquarium staff.

 
Photo: Boston Herald

The skeleton from the Plymouth pilot whale will be given to the state’s endangered species biologist who has a list of museums and aquariums around the world that have requested various kinds of whale skeletons for exhibits.

This pilot whale was  a very unusual visitor for Massachusetts waters. This animal was a short-finned pilot whale, which is a warm water cousin to the local long-finned pilot whales. The normal habitat for short-fins is along the southeast U.S. coast and the Gulf of Mexico. The furthest north that they usually venture is New Jersey.  Prior to last Monday’s event in Duxbury, there had never been a documented stranding case of this species in Massachusetts ever. Last Tuesday afternoon, another young short-finned female had stranded in Truro. Yesterday’s Plymouth death brought the total of short-finned pilot whale deaths to three over ten days. Several other young pilot whales were seen at the Truro stranding. The good news is that those animals were on the Atlantic side of Cape Cod, which has a clear swim path down the East Coast.

As to why these animals came north is the subject of some conjecture. Theories include the possibility of a pod coming north in the late summer and making an abrupt departure as the water temperature dropped and left some animals behind to the possibility of a small cluster of young adults riding a warm water incursion north from the Gulf Stream. Aquarium officials are interested in hearing of any sightings of pilot whales in Cape Cod Bay during the first two weeks of October.

This whale, which had been prominently swimming near the Plymouth Town Pier and the Mayflower pier, had gained much attention from the public and the media earlier in the week. At that time, Aquarium officials had advised the public that the prognosis for the animal was very poor. It was also not a candidate for rescue given its extremely poor health and that pilot whales, which are always in schools, require two animals for rehabilitation. A single pilot whale in rehab can die of the chronic stress associated with social isolation for that species.

The Aquarium would like to extend its thanks to the Town of Plymouth for its help and particularly the staff of the Plymouth Harbormaster’s office who closely monitored the animal and kept curious boaters away from the dying animal. Their diligence, professionalism and skill were invaluable in this multi-day effort.