A small ear-shaped shellfish sits on the ocean floor. Bubbles rise out of tiny breathing holes lining its rugged outer shell. The muscular foot is securely anchored to an ocean rock, while its slender tentacles wave gently in the salty water. The animal is small and likely to go unnoticed, except that its coarse exterior conceals valuable meat and a luminous inner shell, making it a prize catch.
Though most people have never heard of an abalone, let alone seen one, this mollusc once flourished in the waters of Puget Sound. The northern pinto abalone is native to this region, with a population spanning the Pacific coast from northern California to Alaska. Native Americans prized abalone for their meat and colorful iridescent shells, and prior to 1996 there was a thriving sport fishery in Washington state.
Now biologists are trying to bring it back from the verge of extinction.
The pinto abalone is an important part of our environment, said Josh Bouma, a graduate student at the University of Washington who studies the animal. Abalone are marine grazers, meaning they are underwater algae eaters that clear habitat space for other animals. These long-lived gastropods can survive for 15 to 20 years and grow to be 6 inches in length.
"They are really charismatic creatures and really unique. I'm a pretty avid diver and just knowing that there's a possibility of not being able to see them in the future is pretty sad," Bouma said.
In 1982 scientists conducted a dive survey of pinto abalone in the San Juan Islands. In 1991, the Washington State Department of Fish and Wildlife (WDFW) repeated the same survey and results were startling: The abalone population had decreased by 50 percent.
By 1994, when the population in Puget Sound decreased another 20 percent, WDFW closed the sport fishery. The pinto abalone population continued to decline despite the closure, and federal government finally listed the abalone as a Species of Concern.
So few abalone are left in Puget Sound that scientists have trouble locating them for study, said Don Rothaus, a biologist at WDFW. In 2006, WDFW found only 76 abalone at study sites in the San Juan Islands.
While researchers in Washington state explore solutions to revive the dying abalone population, western Canada has enough pinto abalone that they now face a different problem: poaching.
Poaching was a major contributor to the decline of abalone in the Puget Sound as well, Rothaus said, but so few abalone exist along the Washington coast today that it is no longer an issue.
"The U.S. [abalone] population is ten-fold worse than in Canada," Rothaus said.
Although the abalone population along the coast of Canada is also dwindling, the total ban on fishing for pinto abalone in both countries makes the few remaining molluscs a hot commodity on the black market, said Laurie Convey of the Department of Fisheries and Oceans Canada (DFO). In February, a bust in Canada led to the arrest of three poachers possessing 11,000 abalone in the bed of a truck, worth $70,000. Biologists attempted to return the mulloscs to the wild but estimate only 25 percent survived, Rothaus said.
The Canadian government is taking new steps to stop poachers and protect what little is left of its abalone population. Canadian scientist Ruth Withler of the DFO developed a genetic testing kit for abalone meat in 2000. Using this kit, DNA from the meat is used to trace the abalone back to the geographical location from which it was taken, Convey said.
The DFO uses this information to prosecute poachers. Poaching fines are often used to fund more abalone genetic testing or finance the abalone hatchery in Bamfield, B.C.
For Washington state however, a more serious obstacle exists, Rothaus said. Abalone are broadcast spawners, meaning a male must release sperm at the same time a female releases eggs, letting ocean currents combine them. For reproduction to be successful abalone must be close enough together to ensure that egg and sperm meet. This phenomenon is known as the Allee Effect. Abalone need to be populated to a certain density in order to reproduce, and currently abalone populations in Puget Sound are not at this level. Therefore, juvenile abalone are not being successfully recruited to replace the aging adult population. This scenario in effect causes a "Catch-22" for the abalone, Rothaus said.
"You can't have a population increase without successful recruitment, but you can't have successful recruitment without a population increase," Rothaus said.
Other causes of the decline in the abalone population of Puget Sound may include pollution, sport fishing, water salinity, an undiagnosed disease or a natural lull in reproduction, said Brent Vadopalas, a graduate student at the Friedman Laboratory of the University of Washington.
Researchers at the Friedman Laboratory have studied juvenile abalone in Puget Sound since 2003 using Abalone Recruitment Modules, or ARMs. ARMs look like commercial crab pots and contain a concrete cylinder. Researchers leave the pots at sites where abalone populations once flourished. The scientists used 66 ARMs and surveyed six times over the last three years. However, only three juvenile pinto abalone were found, meaning the abalone are failing to effectively reproduce, Bouma said.
In 2003 Canadian researchers began working on a possible solution. Juvenile abalone raised at the hatchery in Bamfield, Vancouver Island, were released, or "out-planted," into Canadian waters. The experiment began in 2003 with the out-planting of 75,000, 8-month-old juvenile abalone. Because abalone take approximately three years to grow large enough to see with the naked eye, no data is yet available to demonstrate how successful the out-planting was, Convey said.
Although no results are available from the out-planting experiments in western Canada the state of Washington, in collaboration with the Friedman Lab, is working to raise money for small scale out-planting studies in the San Juan Islands for February or March 2007, Rothaus said.
There is debate in the scientific community about introducing hatchery-raised abalone back into the wild. These abalone have only a few different parental crosses, meaning the genetics of hatchery-raised abalone may overwhelm the natural population.
Vadopalas said a more natural solution would be to cluster the abalone population to make reproduction more effective.
One thing is certain, Rothaus said: Without human intervention the species will continue to decline.
"If we turn a blind eye every time we lose a species, we lose the richness of diversity." Rothaus warned.