Citing recent research about the group’s numbers and genetic makeup, scientists from Oceana, Center for Biological Diversity and Shark Stewards contend that as few as 350 white sharks could be swimming off the coasts of the United States and Mexico.
“The new science sets off alarm bells for all of us, as no one expected the population to be so dangerously low,” said Geoff Shester, who directs Oceana’s California program. “Great white sharks are powerful allies keeping our oceans healthy, and they need us to protect them far more than we should fear them.”
The sale and trade of great whites is banned under international law, but at least 10 white sharks are accidentally caught each year off the West Coast by gill nets set for other fish. Set and drift gill nets targeting California halibut, white sea bass, thresher sharks and swordfish account for more than two-thirds of young white sharks caught in their nursery grounds.
White sharks swimming off California and Mexico’s Baja California belong to the genetically distinct North Pacific population, and the fact that these animals grow slowly, mature late and reproduce few offspring make them particularly vulnerable. Last year, a study led by University of California at Davis marine biologist Taylor K. Chapple — using photo identification of the sharks’ fins and a mathematical algorithm — determined only 219 adult and juvenile white sharks regularly swim off the central California coast. Researchers estimate an additional 130 white sharks reside off Baja California.
“Even the removal of one sexually mature individual from a population this small can have serious impacts on the population as a whole,” Shark Stewards director David McGuire said.
Monica Allen, a spokeswoman for NOAA Fisheries Service, said the agency “will review the petition on the white shark, and if we find there is substantial information that the action is warranted, NOAA Fisheries will begin a status review, announcing this in the federal register.”
The petition came on the same day that a group of leading American shark and ray scientists, the International Union for Conservation of Nature Shark Specialist Group, issued a report saying 13.5 percent of shark, skate and chimaera species in North and Central America face the threat of extinction.
“Despite significant improvements in regional conservation programs for sharks and rays, overfishing continues to threaten these exceptionally vulnerable animals,” said Sonja Fordham, the group’s deputy chair and president of the advocacy group Shark Advocates International. “The U.S. is home to some of the world’s only success stories for recovery of sharks, and yet many U.S. species still require more stringent fishing limits.