Marine biologists have moved a step closer to their goal of restocking white sea bass along coastal waters by successfully spawning the fish at the Hubbs Institute hatchery at Sea World.
One white sea bass last month delivered more than 100,000 eggs. The size of the delivery was nothing unusual, since one adult white sea bass could lay up to 1 million eggs. The problem was that the scientists did not have the "nursery" ready.
"We were really caught flat-footed because we were expecting the spawn to be much later," said Don Kent, assistant director of operations at Hubbs.
Biologists collected the fertilized eggs and worked to save the fish, but only about 5% survived. However, Kent said, the fact that the fish spawned at all was a boost for the scientists.
In attempting to restock Pacific coastal waters with white sea bass--a species that has been declining for several decades--the Hubbs biologists are conducting a unique experiment. While restocking lakes and streams has proved successful, no one has ever tried to restock an ocean.
"I think we are a little bit farther ahead of ourselves than we thought we would be," Kent said.
The $500,000 state-funded program, approved in 1983, involves marine biologists from UC San Diego's Scripps Institution of Oceanography, Hubbs Institute and San Diego State University. If it is successful, biologists say, sport and commercial fishermen in Southern California could begin finding larger schools of white sea bass.
It will take anywhere from six to eight months before the newly hatched bass grow large enough to be released into the ocean, Kent said. If all goes well, Kent will release at least 5,000 by early next year.
Some of the fish will be kept for experimental reasons, he said. The experiments will include different feeding practices to observe what foods make the young fish grow best.
Some of those released will be marked to allow scientists to trace their growth and feeding patterns if they are caught.
"That's one of the things we hope to find out, how fast these fish grow out there," Kent said.
The newly hatched sea bass are in a larval stage, about half an inch long with no scales, Kent said. If they grow to maturity, they could reach 60 to 70 inches long, or weigh as much as 60 pounds.
Kent said the young sea bass are entering a critical stage because they have large appetites and could eat one another.
"If it's one of their little brothers or sisters, they don't mind that very much," he said.
To reduce that risk, the hatchery is growing small marine organisms to feed the young fish. Scientists hope to soon begin feeding them commercial fish food.
Biologists are trying to breed about 30 adult fish, although they do not know how many are female. The fish will spawn several more times during the summer, and Kent hopes for a greater survival rate with future hatches.
White sea bass are not very important to the commercial market, but in recent years they have become prized catches for sportfishermen.
A similar program for California halibut is being conducted at Occidental College in Los Angeles.
The halibut and white sea bass will be released in coastal waters from Santa Barbara to Mexico.