Severely injured humpback whale disentangled - 8/24/2006

Update, 8/31/06: the humpback whale research team compared photographs of the dorsal fin of this whale to an extensive catalogue of humpback whales from the Gulf of Maine and found no matches. At this time no re-sightings of this whale have been reported.

The PCCS disentanglement team disentangled a severely injured humpback whale yesterday (8/23/06), 30- miles offshore of Chatham, Cape Cod. The whale was found by a tuna spotter pilot who quickly reported the sighting. The whale had a tight wrap of heavy rope around the tailstock (base of the flukes) that was deeply embedded. The flukes of this whale had been reduced to necrotic strips of flesh by its entanglement.

Late in the morning a tuna spotter called in a sighting of a lone humpback barely moving at the surface of the water with rope floating behind it, leading to the flukes. The spotter, a highly experienced pilot who has reported close to a dozen entangled whales to the disentanglement team, noted that the animal appeared in poor condition and had light colored objects in the water in the area of the flukes. The disentanglement team left Provincetown aboard the rapid response vessel Ibis in an attempt to relocate the animal 75-miles away, and 30-miles offshore of Chatham.
 

Diagram of the entanglement. Note deeply embedded wraps of rope around base of flukes.

The tuna pilot had resumed work but quickly re-sighted the whale and directed the disentanglement team to its new location (the whale had moved approximately five-miles to the east). Using a small inflatable boat, the team made a series of approaches to document and assess the whale and its entanglement.

The entanglement was relatively simple, with heavy rope wrapped twice around the base of the tail. This rope hung beneath the whale with the weight of a battered wire-mesh trap and a long length of rope trailed behind the whale.

The injury to the whale was extreme. The wraps of rope had deeply severed the tailstock of the whale and the normally rigid flukes were now soft strips of decaying flesh that trailed behind; completely useless for swimming. The whale was able to make way only with strokes of its flippers. Overall, the whale had pale, patchy skin and was very underweight. The team decided that the removal of the entanglement would help over the short-term, but the long-term prognosis was considered extremely poor, especially considering the likelihood of infection. (Remarkable reports of whales living without flukes have been recorded.)
 

Tailstock in right profile of entangled whale above and same view of a healthy humpback below. PCCS image taken under NOAA-Fisheries permit 932-1489, under the authority of the U.S. Endangered Species and Marine Mammal Protection Acts - please request PCCS permission for use.

The team added small buoys to the line trailing behind the whale in an effort to reduce the weight of the heavy trap. Using this trailing line, the team aboard the inflatable pulled up to the flukes of the whale while the team aboard the R/V Ibis held a long safety line attached to the inflatable, to pull the team out of harms way should the animal, now motionless, become active. Using a series of knives the team slowly cut through the tightly twisted rope just behind the whale. This left two short pieces of rope within the wound that should fall away with time (removing those short lines was deemed too risky for the whale considering the extent of the injuries). The whale then swam off rapidly using its flippers to a remarkable degree.

The gear removed from this whale will be used in ongoing research into entanglement mitigation. The humpback whale research team is attempting to identify this individual whale (obviously hampered by the condition of the flukes, normally used in humpback whale identification). Any updates or future sightings will be posted here. Many thanks to the tuna pilot for all his support during this disentanglement.

click here for a list of previous entanglements