From Around 1,500 Annually, Gray Whale Calvings Fall As Low As 300 In Past 3 Years

SANTA BARBARA — Michael Smith scanned the horizon, searching for the telltale sign that a whale and her youngster were near. With his powerful binoculars trained on the sea, Smith stood atop a cliff and looked up and down the Santa Barbara coast, hoping to spot a plume of water rising up from the diamonds of sun bouncing off the ocean. This is the time of year that mother gray whales shepherd their young up the coastline as they make their long journey from the birth waters in Mexico to the feeding grounds in the Arctic.

Hours passed without seeing the arching backs and exhaled puffs from a mother whale and her calf surfacing for a quick breath. That’s been a common occurrence for years now. “I’m not optimistic,” said Smith, coordinator of the Santa Barbara-based Gray Whales Count, of this year’s offspring numbers. Others agree that this year could follow a three-year trend of fewer calves being born.

“The last three years have been low and I would suspect this year is going to be a low number, too,” said Wayne Perryman, a National Oceanic and Atmospheric Administration researcher who has been studying the dip in the population. During a normal year, as many as 1,500 calves are born into the population that hovers around 20,000 whales along the North American coast. But in the past few years, as few as 300 calves have been born annually. Perryman, who spends hours every spring perched on a Piedras Blancas cliff counting the northbound whales, said fluctuations in the population is to be expected. But the drop could be attributed to climate change and hints at the challenges that may lie ahead.

Perryman said a cold snap in the Arctic for the past few years has created an ice barrier farther south than normal. But climate change has caused the whale’s food source to shift farther north as the water has warmed over time, Perryman said. The ice barrier has cut off whales from their food source, making it harder for mothers to gorge themselves on the prey they normally eat to fatten themselves up for pregnancy. When a mother can’t get the nutrients needed to carry a baby whale to full term, Perryman thinks the body has some kind of physiological cue and it aborts the baby. Females typically get pregnant about every three years and can have babies for about 40 years of their 50-year life span. The cold winters continued through last year and Perryman thinks this year’s migration will also see fewer calves. Because they know what is causing the dip in populations, Perryman is less worried than if some unknown toxin was to blame. “I don’t think it is alarming because we have an idea of what is behind it,” he said. “These are natural responses to the environment.” What it does show, Perryman said, is the challenges climate change will impose on all sorts of creatures as habitat patterns shift.

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http://www.vcstar.com/news/2010/apr/13/climate-change-blamed-as-coastal-whale-migration/