louis martin
cns news & features
Over the next 10 days a project to plant 50,000 juvenile abalone at 5 sites along the North Coast of California will be completed. It is hoped that the project will tell what sites and what methods are best for planting abalone.
Said Dr. Laura Rogers of the Bodega Bay Marine Labs and UC Santa Cruz, "We're taking a lot of data on substrates, algae, predator density, and temperature; and we're looking at growth and survival within these sites."
While the project is a research project, it could yield important results for the commercial fishery.
Five different kinds of sites are being planted, and 2 techniques are being used for planting.
At some of the sites there are adult urchin; at others there are not. A question that researchers hope to answer is whether adult urchin spine canape is important for the growth and survival of juvenile red abalone. Said Rogers of abalone in an urchin environment, "We expect that they might have much-improved survival and growth, because the spine canopy and the spines of adults shelter a lot of small, wild abalone."
The spines also capture drift, which could nourish the young abalone and make for increased growth.
Researchers are also looking at the effect of two planting methods that are being used with the hatchery-bred abalone. Abalone are being planted by divers in "cryptic" habitat, or habitat that is well covered. They are also being planted in "seeding modules." The modules are cement boxes. "They have doors with meltable zinc that open after 18 hours," said Rogers. They serve to protect young abalone for the first 18 hours, but then allow them to walk out into the new environment.
"We don't know whether that's going to be a big improvement or a little improvement or not really significantly different," said Rogers.
Potentially the study could tell fishery managers where and how to plant abalone, but the results will not be known for a year, when researchers plan to go back and "track down the kids." The abalone have been marked with fluorescent tags in their calcium.
Two sites have been planted in Fort Bragg. Single sites have been planted at Salt Point, Bodega Bay, and Half Moon Bay.
Fifty-thousand abalone of 8 to 10 millimeters have been planted. Six hundred 18-millimeter and 200 to 300 28-millimeter abalones have also been planted.
Dr. Rogers, along with Dr. John Pearse of the UC Santa Cruz Marine Lab, heads the project under a grant from the California Department of Fish & Game. Most of the funds come from an "Enhancement Fund"--a self-imposed tax--from the commercial abalone fishery.
(10/10/95)