Endangered humpback whales swam into the Beaufort Sea off Alaska's northern coast this summer, far beyond their usual range, but federal officials monitoring the waters say it's too soon to determine whether it's a trend or an anomaly.
Environmental groups say the presence of humpbacks hundreds of miles north of their usual habitat likely is another sign of the effects of global warming and the shifting Arctic ecosystem. They are calling for more study of the endangered animals' habits before industrial activity is allowed to expand off Alaska's northern shores.
Robin Cacy, a spokeswoman for the federal Minerals Management Service, which oversees lease sales for offshore petroleum drilling in federal waters, confirmed that humpback whales were spotted in the Beaufort Sea east of Barrow, the northernmost community in the United States. Humpback whales were seen in the Chukchi Sea off Alaska's northwest coast last year, she said.
Also, endangered fin whales were detected this summer by acoustic monitoring north of the Bering Strait in the Chukchi Sea, Cacy said. The fin whales were recorded as far north as Point Lay, a coastal Inupiat Eskimo village of 235 about 700 miles northwest of Anchorage.
Some of the whales were spotted by observers involved with the oil industry. Shell Exploration and Production and its contractors performed seismic work this summer in anticipation of bidding on leases. Lease sales are scheduled for 2008 in the Chukchi Sea and 2009 in the Beaufort Sea. Cacy said some whales also were spotted by observers involved with barge traffic.
No one was expecting humpbacks near the activity connected to Outer Continental Shelf lease sales, said Brad Smith, a protective resources biologist for the National Marine Fisheries Service.
"We expected those to be further south and west of the OCS planning areas," Smith said. "We didn't anticipate that they'd been encountered in any of the OCS exploration activity that we're doing this year."
Brendan Cummings, ocean programs director for the Center for Biological Diversity, said the sightings may be an indication of a recovering humpback population expanding its range or of desperate animals in search of food.
Other species that use the Chukchi Sea, from walrus congregating on Alaska's northwest shore to gray whales seeking new feeding areas, are behaving differently because of climate change, he said.
"It looks like the populations are suffering from it," he said. "All signs point to global warming. That would be the first suspect of why the whales are there."
Deborah Williams, a former Department of Interior special assistant for Alaska, and now an advocate for finding solutions to climate change, said the presence of humpback and fin whales so far north has significant implications for the animals' management and development.
"We now have even more compelling reasons to protect the Arctic Ocean and the species dramatically affected by climate change," she said.
Sheela McLean, spokeswoman for the National Oceanic and Atmospheric Administration's fisheries service in Juneau, said humpbacks range widely and have been spotted on the Russian part of the Chukchi Sea. However, humpbacks are not usually associated with pack ice, so sightings further north might be shifts in distribution caused by climate change, she said.
This year was a record low year for pack ice. The National Snow and Ice Data Center at the University of Colorado at Boulder in September recorded 1.65 million square miles of sea ice. That's 39 percent below the long-term average from 1979 to 2000.
Agency to study further
Gary Strasburg, a spokesman for the Minerals Management Service in Washington, D.C., said a sighting of an endangered species in a new area would not mean an immediate change in how the agency regulates petroleum exploration. The agency would determine whether the presence of humpbacks was a trend, and if so, determine the appropriate response, he said.
Federal laws allow a certain level of "harassment" of marine mammals, Smith said. Permits issued in 2007 for exposure of marine mammals to noise from seismic activities covered neither humpback nor fin whales, he said.
"They do, however, have authorization to harass other whales and marine mammals, which were expected to be encountered during the course of their seismic operations," Smith said, including ringed seals, bearded seals, gray whales and bowhead whales.
Conditions imposed upon exploration for humpbacks may be no different than what's in place now, Smith said. The sensitivity of bowhead whales, which remain close to sea ice and are hunted in limited numbers by Eskimo whalers, is considered equal to or greater than the sensitivity of humpbacks, he said.
Cummings does not agree with that assessment of humpbacks — or with the government's protective measures in general.
"These are animals that are entirely dependent on sound," he said of humpbacks.
Permits issued don't take into account the federal government's own research indicating how easily whales can be deflected from their intended paths. The noise could have consequences for whales' feeding and energy expended feeding behavior, especially mothers migrating with their young.
"We don't believe that permits issued to date in the Beaufort Sea comply with the spirit or the letter of the Marine Mammal Protection Act or the Endangered Species Act," he said.
Humpback, fin and bowhead whales are all baleen whales. Humpback and fin whales feed on krill and plankton plus small, schooling fish such as herring or capelin.
Humpbacks are seasonal feeders, building up body fat reserves in the summer and migrating to warmer, subtropical areas during the winter breeding season.
Full-grown humpback whales average 42 feet long and weigh 25 tons. Females average 45 feet long and 35 tons.
Fin whales are even larger. The long, slender whales grow to nearly 88 feet, the second longest of the whales behind blue whales.