Stranding of a humpback whale (Megaptera novaeangliae) on the Belgian coast

On March 1st, 2006, a large cetacean, estimated 10 m long, was observed dead, drifting at 2 nautical miles off Calais (France). Computer models predicted a north–eastwards drift of the carcass and a stranding within two days or less. Five days later, on March 5, a humpback whale was found dead on the Belgian coast (Lombarsijde). It was presumably the same animal. The later reprocessing of the observations at sea resulted in a better definition of the parameters used for predicting the drift of such large bodies. The animal was necropsied. It was a juvenile female of 10.5 m. The blubber thickness was 11.5 cm and the body weight was 15 tons. External examination of the left pectoral flipper revealed multiple ante-mortem fractures of the radius and the ulna. Internal observations revealed various intramuscular hemorrhages in the head and neck area. Otherwise the muscles were red pinkish. There was evidence of intraperitoneal hemorrhage. The whale had been in good health with a good nutritional status (normal blubber thickness) and fresh preys were present in the stomach. Both observations suggested that the cause of death was an acute process. The observed lesions (bones fractures, intramuscular and intraperitoneal hemorrhages) suggested a severe trauma, almost certainly a ship collision. Large cetacean deaths related to ship strike and net entanglement are reported with increasing frequency in the North Sea. Only the necropsy of all stranded animals could help evaluate the actual impact of such accidents