By Erin Sherbert
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Gray whales tend to calve every other year. In 1998, seven females returned to Pil'tun with calves. Researchers expected that at least some of the seven would arrive in 2000 with calves. All seven came back to Pil'tun, but they came without calves, preliminary reports indicate.
"Thus, the 1998 mothers either did not produce calves or lost them before arriving to the feeding grounds," the report says.
Four of the seven returning mothers were also tentatively identified as unusually thin in 2000.
"The lower than expected number of calves observed off Pil'tun in 2000 may be due to the poor physical condition (i.e. thinness) of some females, as "skinny whales' are unlikely to become pregnant, carry a fetus to term, or successfully suckle a newborn calf," says the preliminary report, which is subject to revision.
The four females were among as many as 27 "skinny" whales identified in 2000, up from a dozen in 1999.
"We are not exactly sure what's going on there," Weller says. "Some of those whales are repeats from 1999 to 2000. They are still looking thin but have survived and are making it."
Scientists also began seeing skinny Eastern Pacific gray whales in 1999 and 2000.
"The explanation for the Eastern group is they are nearing carrying capacity [maximum population], and they are having a hard time finding food," Weller says. "But I don't think that really holds much weight right now because we are seeing the same thing on the other side of the Pacific, and that population is nowhere near carrying capacity.
"We are not ready to point the finger at anything in particular until we can get a better handle on what's happening with both populations," he says. "It's a bit of a puzzle right now."
Some of the theories being tossed about include disease; cumulative effects of stress from the oil project, including sudden exposure to underwater noise while feeding; or some unknown phenomena.
"It could be that the food resources are truly poor for them," Weller says. "And it could be a cyclic and natural type of thing where those food resources are really great for some years and for some years they are really quite diminished."
Or the food supply for both Eastern and Western Pacific populations could be crashing because of global warming.
"It could be," Weller says. "Or it also could just be coincidence."
Continuing to study the Western Pacific grays is crucial to developing a plan to save them. Scientists need to learn more not only about their feeding grounds in Sakhalin, but also about their migratory route and the locations of their winter lagoons. It's important because besides threats from oil drilling, the whales face danger from ship strikes, entanglements in fishing gear, and illegal hunting.
Once at a population of 15,000, the Western Pacific grays have been one of the most intensely harvested whale populations in the world. Unlike the Eastern Pacific gray whales, whose numbers rebounded to 26,000 from a low of 3,000 before their hunting was banned by the International Whaling Commission in 1946, the Western Pacific grays continued to be exploited into the 1960s by commercial whalers off the Korean coast.
Despite the 1986 moratorium on commercial hunting of almost all whale species, Japanese fishermen continue to hunt the Western Pacific grays.
Brownell documented one illegal take of a Western Pacific gray by Japanese porpoise fishermen in May 1996. He confronted the Japanese in 1997 and 1998 at the annual IWC meetings.
"Their reaction is sort of the usual," Brownell says. "They said maybe it was killed by some people someplace else and floated down. They always make up stories for trying to explain it.
"Of course, the likely scenario is the one that turns out to be the case. We know they took it. I've got pictures of the harpoons that were taken out of it. The harpoons are used by some other fishermen that hunt something called Dall's porpoise in the area.
"They just had a chance to get this whale and decided, "OK, we can get this.' They ended up using only half of it, and half of the carcass came on the beach, the head end," Brownell says.
More evidence has turned up in recent months showing that the Japanese are selling meat from Western Pacific gray whales as well as other endangered whales in commercial fish markets.
Researchers from the University of Auckland have been testing DNA samples of whale meat sold in Japanese and South Korean fish markets since 1993. The Japanese are allowed to hunt several hundred minke whales, which are relatively abundant, under a "scientific" exception to the IWC's 1986 commercial-whaling moratorium.
But the DNA records from two 1999 fish market surveys show the Japanese selling far more than minke whales.
"More than 14 years after the moratorium, there is a surprising diversity of whale species currently for sale in commercial markets, and some of these products are from protected species," states a recent report by C. Scott Baker of the University of Auckland.
"The 1999 surveys include two species not previously found in market surveys, the gray whale and the finless porpoise."
Baker says that he has found seven gray whale samples from Japanese markets.