San Diego Union-Tribune (Sunday)
FISH • Scope of research program to expand to all marine species
Agua Hedionda Lagoon, across the water from the Encina power plant and the Carlsbad Desalination Plant.
The new legislation, AB 1949, expands the scope of the program to include research on all species of marine fish that have an economic impact on California.
“This legislation will allow for the state to continue to invest in the science and research necessary to adapt to inevitable changes in the marine environment and usher in new productivity at this amazing facility,” said Bill Shedd of the Coastal Conservation Association of California, chairman of the hatchery program’s advisory panel.
California halibut initially were included in the hatchery program, but the efforts shifted to a single species after a few years, said Mark Drawbridge, director of the program for the Hubbs-seaworld Research Institute.
“There just wasn’t enough funding to do all that is needed for two species at once,” Drawbridge said. “There is so much involved in raising the fish and making sure they are healthy.”
Fish bred at the hatchery are tagged with a microscopic piece of stainless steel wire placed in their cheek, he said. White seabass sold in commercial markets are scanned with sensors to look for the tagged fish. Recreational fisherman are asked to save the heads of the species and return them to a collection point, such as Helgren’s Sportfishing at the Oceanside harbor, where the heads are stored in a freezer for the survey.
Surveys so far have not been as productive as researchers hoped, Drawbridge said. Only about one tag turns up in every 300 fish scanned, but there could be many reasons for that. Researchers are studying the possibility that some of the tags become demagnetized or are shed by the fish.
Ideally, the hatchery would produce up to 10 percent of the white seabass caught, he said.
The hatchery produces about 100,000 fish a year, Drawbridge said. When they are about 3 inches long, the fish are placed in cages in the ocean along the Southern California coast. They grow to 8 or 10 inches long in the cages before they are released into the open water. The larger fish have a better chance of surviving on their own.
White seabass take about five years to reach the legal size for catch, which is a minimum length of 28 inches or about five pounds. The largest hatchery-bred fish ever caught was 20 years old and weighed about 20 pounds, Drawbridge said.
Wild white seabass can grow to 90 pounds, but it’s rare to catch one over 60 pounds, he said.
Commercial fisherman have sought the species since the 1800s. The total catch varies widely over the years and depends on many things such as the market, water temperatures and other natural factors. It peaked in 1959 when 3.5 million pounds were landed in California, according to the state Department of Fish and Wildlife.
Today the species remains popular on the dinner table and sells for about $30 a pound in California fresh fish markets. The populations remain healthy north of Point Conception, but are considered depleted along the Southern California coast.
A recent study showed as many as 10 fish species, including kelp bass, giant seabass and California sheephead could be introduced into the hatchery program. The hatchery recently resumed its efforts with California halibut and did its first release of a little more than 2,000 fish last October in Mission Bay. Released at about 6 inches long, the halibut will take three or four years to reach the legal catch size of 22 inches.
Also, the hatchery has been researching California yellowtail, a species more likely to be farmed using traditional aquaculture methods, like salmon, than to be released to the wild. Yellowtail farming could take some of the commercial fishing pressure off the species, Drawbridge said.
Two sources provide most of the funding to operate the Carlsbad hatchery. The largest part of the money is collected from the $5 fishermen pay for the ocean stamp when they buy their annual state fishing license. Another significant source of revenue is a federal tax on fishing gear such as rods, reels, lures and other equipment.
The Hubbs Seaworld Research Institute started the program in 1982 in San Diego before building the Carlsbad hatchery.