Source:  “A Winter’s Watch: Scientists Track Whale Migration From Big Sur Bluffs” from the Monterey Herald website.

The census in 2011 estimated the current population to be about 21,000, a number that’s been relatively stable for the past 10 years.

“This year, we want to see a stable population or one that’s slightly increasing,” Weller said.

That would be good news for whale watchers, too. Richard Ternullo, the owner of Monterey Bay Whale Watch, said business has been solid so far this season.

“The weather’s been good, so people have been out,” Ternullo said. “It seems like a pretty normal migration in terms of the number. Maybe it was a little bit early as far as when we started seeing the migrants.”

Detecting shifts in when the whales start arriving — and especially when the peak number goes by — is a secondary goal of the census.

“Every given year it might shift a little bit forward, or a little backward,” Weller said.

Whale biologists are also interested in whether the declining levels of Arctic sea ice will affect migration patterns.

“The receding ice is not necessarily a negative thing in the gray whale case,” Weller said.

That’s because it opens up new habitats, and no one is sure what effects this will have on gray whale behavior. But the biggest mystery is still why the whales migrate at all.

“Some people believe they migrate away from areas where calves are in danger,” Weller said, adding that this is his favored explanation.

Another explanation holds that the demands of giving birth require the whale moms to be in warmer waters for energetic reasons. These questions will require many future studies to decide.

For now, this year’s count is still up in the air.

“We won’t really know until the whole thing is over,” Weller said