By Amy Silverman
By Olivia LaVecchia
By Monica Alonzo and Stephen Lemons
By Chris Parker
By Michael Lacey
By Weston Phippen
Researchers have gotten better since the 19th-century observations of Townsend at extrapolating from a head count to a population size. But this relatively simplistic whale census still remains the basic tool for determining the health of the species.
For more than 30 years, the Granite Canyon station has been the official site for what NMFS calls "abundance estimates." Individual observers watch the whales through binoculars mounted on a stand and focused on a particular spot in the ocean. Same spot, day after day, year after year. Scientific consistency also calls for the observers to record their numbers by hand on a form that also has remained relatively unchanged for years.
"It's a primitive mechanism," concedes Dave Rugh, an NMFS biologist who oversees the counts, "but it's the same one that was used in the '60s."
That way, changes in technology do not skew the methodology or, hopefully, the results. In recent years, NMFS has added aerial surveys and underwater sensors to the mix as a way to confirm what the onshore watchers are seeing.
The count usually begins in mid-December. By the time it ends in mid- to late February, observers will have spotted more than 3,000 individual whales. Those numbers are run through a computer model that factors in density and other variables, then gives the estimated size of the population.
The latest report continues to put the total number of Eastern Pacific gray whales at more than 26,000, an ecological success story considering that in the 1930s the population had dropped to fewer than 8,000, and the whales were put on the U.S. Endangered Species list in 1970.
In 1937, the gray whales were protected from commercial hunting by international agreement, a ban that was formalized in 1946 with the advent of the International Whaling Commission. U.S. monitoring of gray whales has been going on since the 1950s.
By 1994, the Eastern Pacific gray whales had rebounded significantly and were removed from the list. (The Western Pacific gray whale continues to be listed as a "critically endangered" species.)
Earlier this year, volunteers who staff a whale-watching station in Southern California reported that the 2001 migration has been a healthy one.
"I saw some of the biggest, fattest whales I'd seen in quite a while this year," says Alisa Schulman-Janiger, a high school marine biology teacher from San Pedro, California, who oversees the volunteer count as head of the Los Angeles chapter of the American Cetacean Society.
From December through May, volunteers peer out to sea from atop a 125-foot-high cliff near Point Vicente, just south of L.A. They use binoculars and spotting scopes to capture a view of passing marine mammals and other sea creatures. They rely on years of experience and training to be able to spot a hump in the water hundreds of yards out, and then figure out if it's male or female, young or old, fat or skinny.
The whales head north in two pulses, according to Schulman-Janiger. The first includes animals without calves and, about six weeks later, the watchers begin to document mothers with calves.
The volunteers had been dreading this season, anticipating a third year of starving whales.
Instead, Schulman-Janiger's final report calls the spring 2001 migration an "exotic season." Volunteers documented a large number of marine mammal species, including humpback, blue, minke and killer whales, two very rare sei whales, sea lions, seals, sea otters and numerous species of dolphins. One "megapod" contained more than 10,000 dolphins, she reported.
Schulman-Janiger doesn't think there will be a lot of strandings during the coming migration. She expects to see more calves and an overall healthy look to the whales that would suggest they're feeding well and perhaps expending their feeding ranges to other areas. "I would predict the whales will continue to look fat and sassy," she says.
"Next year is going to be extremely telling."
Over the years, scientists have become comfortable with a gray whale population that appeared to be growing at the rate of about 2.5 percent per year, measured from the 1960s through the 1990s.
But several years ago, something went seriously awry. By the end of the 1999 migration, at least 263 gray whales had stranded, compared with 52 the year before and even fewer than that per year for many years prior.
The 2000 migration was even worse -- more than 350 gray whales turned up dead.
And those were just the ones that came ashore or were found floating in nearshore waters. No one knows how many grays perished and vanished in deeper waters.
One thing was clear, even as the first few dozen whales began to litter the beaches of Baja early in 1999 -- the whales were starving. Reports of emaciated whales began to flow in with what seemed like every new tide.
Some researchers began calling for serious efforts to determine why the whales appeared to be undernourished. Logically, they reasoned, that would mean looking at the whales' primary food supply -- the shrimplike amphipods that live in the mud on the bottom of the Bering and Chukchi seas, off the coasts of Alaska and Russia. The whales eat only in the summer, sucking in large amounts of muck and screening the amphipods through their baleen.