NEWS & PUBLICATIONS

   For thousands of years, humans have removed fish from the sea, giving little thought to how their actions affected the marine landscape. The vast size of the oceans - accounting for more than 70 percent of the Earth's surface - gave the impression that these waters held infinite numbers of fish and other resources.

   But as technology to harvest seafood expanded and evolved, so did the push to put increasingly rare marine specimens on dinner plates. Among these delicacies was a resident of Channel Islands National Park in California: the white abalone, a bottom-dwelling mollusk favored by consumers for its tender white meat.

   Originally found in Southern California's waters on rock surfaces 80- to 100-feet deep, the white abalone population took a dive roughly 35 years ago when fishermen removed the creatures at a rate faster than they could repopulate. This came on the heels of declines among other species of abalone, also depleted by over-fishing.

   But scientists didn't notice a void until the mid-'90s, when they linked the absence of abalone to legal fishing that took place between 1969 and 1977.

"Somewhere along the line, we realized we hadn't seen a white abalone in quite some time," says Dan Richards, a marine biologist with Channel Islands National Park.

   In 1999, park scientists at Channel Islands began a concentrated effort to inventory the species via submarine expeditions and diving surveys in locations where white abalone were historically known to occur. Only a handful were discovered, and they were largely isolated from each other.

   Such fragmentation presented a huge challenge for the survival of the species. White abalone are "broadcast spawners," releasing millions of eggs or sperm into the water during spawning events that occur yearly between February and April. The few individuals that remained were too far apart for their eggs and sperm to meet, and propagation plummeted. In June 2001, the white abalone became the first marine invertebrate mollusk to be federally listed as endangered.

   "The white abalone is just the canary in the mineshaft," says Gary Davis, a visiting chief scientist with the National Parks Service's Oceans Pro-gram. "It's a unique life form, and was selling for $100 each when the fisheries closed [in 1997]-but its real value is that it has provided a wakeup call to fix our marine ecosystems."

   In 2001, scientists began a captive breeding program at the Channel Is-lands Marine Research Institute that focused on retrieving wild adults, breeding them in a hatchery, and raising their offspring. What started with four successfully spawning individuals has led to the 10,000 white abalone in captivity today.

   But the hatchery faces its own set of problems. Some of the mollusks suffer from the bacterial "withering foot syndrome," which causes the foot muscle to weaken, hindering movement and the foot's ability to adhere to surfaces and eventually leading to death. The Park Service also has struggled to find enough money to feed the resident abalone so the animals can grow healthy and large enough to be released back into the wild. In total, it costs about $100,000 to run the hatchery each year. And releasing captive-bred mollusks is a hurdle scientists have yet to clear, as they must first ensure that individuals are genetically diverse enough to make up a healthy community in the wild.

   Keeping tabs on populations in the wild is a whole different ballgame. "The depth at which remnant populations of white abalone live make it difficult to assess remaining numbers," says Thomas McCormick, vice president of Research at the Channel Islands Marine Resource Institute. "However, marine scientists believe that 30,000 white abalone may remain in waters off southern California." While this may sound plentiful, this number is down from the 22 million white abalone scientists believe existed 30 years ago.

   But Davis and his colleagues are optimistic, partly because the idea of establishing no-take zones-areas that ban commercial fishing - is catching on. Research shows that these protected areas can act as "nurseries" for a variety of species, eventually increasing populations outside of the no-take areas. In Channel Islands National Park, ten separate no-take zones are in effect.

"Our goal is not to change the [fishing] industry," Davis says. "Instead, the Park Service is beginning to explore how parks might produce environmental benchmarks and be sources of replenishment for fisheries."