Seen on Georges Bank
Teri Frady, NOAA
NMFS Northeast Fisheries Science Center
N E W S
Seen on Georges Bank
Woods Hole, MA A small team of marine mammal experts is on eastern Georges Bank today to gather data that may help determine what happened to several large whales recently spotted dead in the area, and whether there are any more.
The effort was organized by NOAA Fisheries, the federal agency charged with large whale protection and recovery. The team is aboard a U.S. Coast Guard cutter, with members hailing from the Cape Cod Stranding Network, the Center for Coastal Studies in Provincetown, Mass., and the Woods Hole Oceanographic Institution. NOAA Fisheries whale aerial survey team is providing air sighting support.
Canadian fishery officers aboard the Canadian Coast Guard vessel Sir William Alexander are also searching the waters on the Northeast peak, and are prepared to recover samples. Both the US and Canadian vessels are expected to be in contact with one another to share information during the operations.
This many adults, dead, in close proximity to one another is almost unheard of in the large whales without some kind of instigator, said Dr. Phillip Clapham, a NOAA Fisheries expert on humpback whales in the North Atlantic who is advising the team.
The only other case of numerous dead humpbacks in the past 20 years occurred in 1987-88, during which 14 animals stranded dead on Cape Cod between November and January. Those deaths were eventually traced to food, he said. The whales had eaten fish carrying lethal concentrations of a toxin produced naturally during harmful algal blooms, in humans this toxin causes paralytic shellfish poisoning. Clapham noted that while the pattern of the recent deaths suggests that a similar event might be in progress, more data are needed to determine their cause, we are still at the beginning of this investigation.
Three floating dead humpbacks were spotted within 16 miles of one another by the aerial team on July 3, approximately 160 miles off Cape Cod. Poor weather prevented attempts to resight or sample the carcasses.
On July 23, a U.S. Coast Guard vessel reported a dead floating humpback to the north of the first sightings. Again, weather precluded a sampling or resighting effort.
On July 28, the aerial survey team located three dead humpbacks and one dead fin whale on Georges Bank. Two of the humpbacks and the fin whale were on the Canadian side of the Hague Line, the international boundary separating U.S. and Canadian waters in the Gulf of Maine. All of the sightings are within an approximately 50-mile radius.
There were no obvious signs of trauma on the portion of the carcasses visible to observers. It is not certain whether each of the seven humpbacks sighted are distinct individuals.
With good weather expected, the U.S. Coast Guard Cutter Tahoma, with the mammal team aboard, is on its way to the vicinity of the earlier sightings. The NOAA aerial team is surveying the area to locate carcasses or live animals. The at-sea team will document as much as possible about the carcasses, make observations of any live animals in the area, and attempt to retrieve samples that might prove useful in determining the cause of death or identifying the animals. Humpbacks in and around the Gulf of Maine have been subject to intense observation in recent decades, and many animals are individually identifiable from fluke markings or by matching with banked genetic material.
The most recent stock assessment for humpbacks in U.S. waters estimates a population of about 900 in the Gulf of Maine, while the total North Atlantic population is likely more than 12,000. Humpback whales are both protected and listed as endangered under federal laws.