After 30 million deaths, farmer seeks new seed

07/29/2010

Three weeks ago, when Drakes Bay Oyster Company owner Kevin Lunny went out to check his five outdoor cultivation tanks, each containing six million oyster larvae, he got a nasty shock: the larvae were dead. Months of work and $10,000 were gone. Complete larval failure has recently become common for the oyster farm, which traditionally sees very good oyster yields. Lunny said it is probably due to ocean acidification—decreases in water pH caused by carbon dioxide from the atmosphere settling into the ocean.

“I wondered, did we just fill our tanks with corrosive seawater and kill our larvae?” he asked. Lunny wants to cultivate native oysters, which he believes are more resilient to acidic water and more conducive to the health of Drakes Estero than the Pacific oysters he now cultivates. Last March, for the third time, he requested that the California Fish and Game Commission consider allowing him to add native oysters to his cultivated species list. And on June 28, for the third time, Point Reyes National Seashore moved to block Lunny’s application, which is now too late to be considered at the commission’s August meeting.

Seashore officials claim that they merely want to examine the proposal before it gets submitted to the commission. But Lunny claims that the Seashore’s actions run contrary to the guidelines in the farm’s lease agreement. “I thought we were past this part of our relationship,” he said.

Lunny claims that, according to his agreement with the Seashore, all changes to his cultivation must first be approved by the Fish and Game Commission. After a proposal passes the commission’s notoriously stringent scrutiny, the proposal goes to the Seashore for final approval.

Seashore officials claim that there are no sinister motives behind their desire to inspect the proposal first. “There’s been no denial on anything, just a request for communication,” said spokesman John Dell’Osso. “It’s kind of odd for us, as landowners, that we haven’t seen this proposal yet.” Lunny said that he is not opposed to giving the Seashore his proposal, but he has not yet done so. His request will now have to wait until the next commission meeting in September.

The hypothesis that ocean acidification is the culprit for Lunny’s larval die-off seems to hold water. Scientists at the University of California at Davis Bodega Marine Lab have experimented with tanks that simulate future oceans, and their effect on native oysters. “We’re seeing really large effects on their shells at these early life history stages,” said researcher Annaliese Hettinger.

Oystermen along the coast have also been examining native oysters as an alternative sustainable food source. Reestablishing native populations would provide a self-sustaining food source that is more resilient to changes in ocean chemistry. But few farms are able to reintroduce the native Olympia oyster because, while they remain the same species, oysters adapt genetically to their environment. Imported Olympia oyster larvae can interbreed with the small populations of local native oysters and destabilize that population’s gene pool.

Lunny is presented with a unique opportunity for native oyster population because he does not need to import larvae—there are enough native oysters in Drakes Estero to spawn, with care, large oyster beds. The native oyster beds could sit next to Lunny’s Pacific oysters, which are originally from Japan, because the two species cannot interbreed.

Ecologists and oceanographers are largely in favor of native shellfish repopulation because reefs clean waters and provide habitat variety for other species. “It’s about being more in harmony,” said Brian Kingzett, field station manager for Center for Shellfish Research in British Columbia. “Having a large bed of these oysters goes a long way to reestablish native populations.” Kingzett said that millions of native oysters in one area will synchronize their spawning and send large clouds of larvae, some of which are likely to settle and grow in other areas of the estero. “They maintain environmental integrity and provide food and habitat for crustaceans and juvenile salmon,” Kingzett said. “Making the decision to farm native oysters—right off the bat you’re making the right decision.”

Lunny remains hopeful that Seashore Superintendent Cicely Muldoon, who could not be reached for comment, will allow the proposal to go forward. “I think if the Park Service realized what they have in their midst, they would embrace it,” he said.