Can cultured cobia enhance wild stocks?

(July 8, 2003) Researchers at the Virginia Institute of Marine Science today released 125 tagged cobia, weighing between 2 and 4 pounds, from the VIMS Gloucester Point beach.

Mike Oesterling, a commercial fisheries specialist in VIMS' Sea Grant Marine Advisory Services program, headed the release event, which is the first step in a program designed to investigate whether hatchery-reared cobia can be used to enhance wild stocks.

"Increasing fishing pressure on cobia, already a highly sought-after recreational fish, raises the question of future stock-enhancement needs," says Oesterling.

Data from the capture of tagged fish by recreational and commercial anglers will help Oesterling's group answer some of the many basic questions that exist concerning the possible use of cultured cobia for stock enhancement.

"Will cultured fish survive in the wild once released? Will they return to the release area? Will they be assimilated into the wild population? Our release will be the first step toward answering these questions for Chesapeake Bay," says Oesterling.

The tags, which resemble the plastic price tags that stores attach to clothing, feature a phone number and offer a small reward for calling with information on the fish's weight, length, and location and date of capture. The tags are attached to the left "shoulder" of the fish near the dorsal fin and colored yellow to distinguish them from similar orange tags used by the Virginia Marine Resource Commission.

The planned release is the latest step in a cobia-culture project that has already generated several firsts. Oesterling's group was the first in the U.S. to successfully spawn cobia and raise the larvae to fingerling size in a hatchery, and the first to grow the larvae to market-size in a re-circulating seawater system.

The group's success has jump-started cobia aquaculture in the U.S. A commercial hatchery has been producing cobia fingerlings for commercial grow-out for two years, and the first truly commercial harvest of U.S.-spawned and raised cobia occurred earlier this year.