Sixteen years after the gray whale was taken off the endangered species list, the California Gray Whale Coalition says their numbers are dwindling again and is leading a campaign to protect the marine mammals further declines.
As a first step toward the goal of having the gray whale listed as endangered once again, the Coalition has petitioned the U.S. National Marine & Fisheries Service to list the Eastern North Pacific gray whale population — also known as the California gray whale — as depleted, a designation which would then prompt the agency to develop a conservation plan.
“The gray whales are facing challenges on all fronts, hunting, killer whales, low cow/calf counts, climate change,” said Sue Arnold, chief executive of the Gray Whale Coalition, which is based in Palo Alto and has representatives in Santa Cruz. “Where do you draw the line in the sand?”
While the number of calves produced by gray whales have been counted continuously for the last 16 years, an abundance study for the total population has not been done since 2006-2007, when there were an estimated 19,000 whales according to the National Oceanographic and Atmospheric Administration.
The Southwest Fisheries division of NOAA is in the midst of a new two-year abundance study. The first phase was conducted in January during the whales’ winter migration and a second set of data will be gathered in January 2011. The results will not be available until at least a year from now, said biologist Wayne Perryman of Southwest Fisheries.
Gray whales were listed as endangered, with an estimated population of 17,000, under the U.S. Endangered Species Act in 1973 and removed after their numbers reached 20,000 in 1994.
The “depleted” designation requires a petition under the Marine Mammal Protection Act, while labeling the gray whale as either threatened or endangered — signifying a greater peril than depleted — would require a petition under the Endangered Species Act.
In 2001, when estimates put the population at 16,000 as an unusual amount of gray whales were stranded and found emaciated, a petition was filed to place the cetacean back on the endangered species list, but sufficient evidence was not found to warrant re-listing, said Fisheries biologist Tom Eagle.
While observers of the gray whale population are in agreement that the number of calves has significantly dropped in the last three years — averaging 423 per year from 2007-2009 and 1,164 per year between 2004-2006 according to NOAA — there is disagreement as to why.
“I don’t necessarily think there is cause for alarm,” said Leah Gerber, a biologist at Arizona State University who studied the original decision to drop the gray whale from the endangered species list.
“A new carrying capacity is being established, and it makes sense biologically that the reproductive rate would be lower as the population adjusts to a sustainable level. I would not say there is high probability of extinction in the foreseeable future which would be the criteria for listing it as endangered.”
The calf count is prone to fluctuations due to a variety of reasons, and is not, by itself, cause for alarm, said Perryman.
The California Gray Whale Coalition, in its petition, attributes the threat to gray whales to five main causes: over-estimating the population which has led to over-harvesting; the drop in cow/calf numbers; predation by orcas; major changes in habitat and prey due to climate change; and a reduction in available prey species.
The gray whale, which undertakes one of the longest annual migrations of any mammal traveling between 9,000 and 12,500 miles a year between the Arctic and the Baja Peninsula, is particularly susceptible to climate change.
Currently, the International Whaling Commission has a quota for gray whales of 140 per year, most of which is designated for a Russian exception to the commercial whaling ban for “aboriginal/subsistence whaling.”
The Native American Makah Tribe of Washington — which has traditionally hunted gray whales — has sought a waiver to the Marine Mammal Protection Act, but legal challenges have mostly prevented the Makah from hunting.
“If the gray whale were listed as depleted then (National Marine & Fisheries Service) could not support the waiver to the Marine Mammal Protection Act,” Eagle said.
Arnold and the coalition argue that the IWC quota was set on faulty population figures and hopes to see a moratorium placed on all gray whale hunting.
The gray whale population data due out next year from NOAA should help clarify the matter.
“I think it’s time for a new population estimate,” Gerber said. “The new data will be interesting, and if that suggests a steep decline there is merit to the petition.”
However, the new data will not be available during the period that the National Marine & Fisheries Service evaluates the petition.
“The U.S. government has responsibility of doing the counts and seeing to the maintenance of a viable population,” said Burney Le Boeuf, professor emeritus of biology at UC Berkeley. “But they are slow to put out this information, and the terrible irony is that if the animal is in danger you have to proceed more rapidly than that.”
The National Marine & Fisheries Service 60 days to respond to the petition, which was filed Oct. 21. If significant evidence is presented to warrant further study, the agency then has an additional 150 days (210 from the petition date) to review the population status and rule on the petition, said Eagle. Once a ruling is published there will be a 60 day comment period, after which the National Marine & Fisheries Service is obligated to publish a final ruling within 90 days.