NOAA Observes Killer Whales After Valdez
ANCHORAGE − It's probably too late to save a small pod of killer whales whose numbers plummeted after the Exxon Valdez tanker spilled nearly 11 million gallons of oil into Prince William Sound.
But scientists said all may not be lost. The legacy of the AT1 group -- now numbering as few as seven orcas -- could be what is learned to help other whales.
"We need to do whatever we can," said Bridget Mansfield, a National Oceanic and Atmospheric Administration fisheries specialist who led a three-hour discussion Wednesday on what should go into a recovery plan. "Realistically, I think it is really hard to say we can do anything to save this group."
Craig Matkin, a marine mammal biologist with the North Gulf Oceanic Society who has been studying the whales since the 1980s, agreed.
"You have to be damned optimistic to think they can be saved," he said.
Despite the dire outlook, Matkin and about 15 other researchers and scientists, as well as some tour boat operators, tackled the question of a recovery plan. Mansfield said two more meetings would be held in the spring to refine it.
NOAA designated the group of transient killer whales as depleted in June. The designation requires that the agency come up with a recovery plan unless it is determined the whales are beyond hope. There is no timetable for finishing the plan.
Suggestions for the plan included placing transponders on the two females most likely to breed to keep whale watching boats well away. The group has not produced a calf in 20 years.
Participants said protections around harbor seal rookeries is a good idea given that seal populations in the area have fallen by over 50 percent. Transient killer whales travel in small groups and feed mostly on marine mammals instead of fish.
One participant stressed the need for more restrictions on shoreline development.
Matkin said boat traffic noise needs to be quieted not only in the sound but in Kenai Fjords where the whales have been seen more often lately.
"They need to hunt. They need quiet to hunt. Having boats all around them doesn't help," Matkin said.
The situation has worsened since word got out that there are so few whales left in the AT1 group, Matkin said. Instead of keeping away, some tour boat operators are crowding them and staying too long.
"I think this is a serious issue," he said.
When the group was first recognized in 1984, there were 22 whales. Scientists discovered the pod was genetically different from other transients in Alaska. The AT1 group also had its own distinctive "acoustic repertoire," according to a NOAA status report.
"Until we saw the animals, it was hard to believe they were so unique and cut off," Matkin said.
Eleven members have not been seen since 1989 when the Exxon Valdez ran aground. One of those whales is known to have died and the others are presumed to be dead.
Numbers have continued to slip. With such a small group, the females likely are suffering from "incest avoidance behavior," said Lance Barrett-Lennard, a research scientist at the Vancouver Aquarium in British Columbia who has worked with Matkin and other North Gulf Oceanic Society researchers. Data shows pod members are closely related.
"Effectively, they've run out of mates," Barrett-Lennard said.
To make matters worse, a necropsy on a male in 2000, showed high levels of DDT and PCBs, probably from chemical plants in China and Southeast Asia.
It's also unknown whether the whales are still suffering from the effects of the Exxon Valdez oil spill, Matkin said. When the spill first occurred, the whales probably died from inhaling the oil and were sickened from eating oil-coated seals. Studies have been insufficient to determine what effects there are now, he said.
Matkin said if nothing else the story of the AT1 whales points to the importance of paying closer attention to these animals.
"They are a species where population numbers are small and things can change rapidly," he said.
Source: Associated Press