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Cobia Released on Popular Mississippi Offshore Artificial Reef

BILOXI, Miss. – The Mississippi Department of Marine Resources (MDMR) in Biloxi continues to move forward with its dedication to restocking the marine waters of Mississippi. The latest restocking effort was of historical proportions with the ever-popular cobia. The MDMR, with the help of Aqua Green of Perkinston, Miss., made history with the first successful release of 7,500 cobia around Fish Haven 9 on the north side of Ship Island on Dec. 8 and 9.

The 6- to 8-inch long cobia were loaded at the Biloxi Small Craft Harbor on the MDMR boat, Fish Haven, using three tanks. It took two months at Aqua Green for the fish to grow in overall size, from 2-to-3 inches long to the current release size at six months of age.

MDMR's Cobia Stock Enhancement Program was financed through the National Oceanic and Atmospheric Administration’s Emergency Disaster Recovery Program, which was funded by Congress in 2006 to aid in the rehabilitation and recovery of marine fisheries in the Gulf of Mexico following hurricanes Katrina, Rita and Wilma.

"This was a pilot program," Mike Brainard, a marine biologist with the MDMR, said. "We contacted Aqua Green, which is an aquaculture facility in Stone County, and wanted to utilize the various expertise of the private and public sector including Mississippi State University and the Gulf Coast Research Laboratory at the University of Southern Mississippi.

"This is the first large-scale stocking project to raise and release cobia in the northern Gulf of Mexico that I know of. We are very pleased and it went as well, if not better, than we expected."

To ensure the highest rate of survival at the time of the release, Shelly Nicholls of Aqua Green, monitored the tanks and kept the dissolved oxygen levels at 9 parts per million from the Biloxi Small Craft Harbor to the release site. Other crucial ingredients to a successful release were properly matching salinity levels between 28 and 30 parts per thousand and the water temperature.

At the release site, Nicholls and the MDMR staff circulated water in the tanks from the Biloxi Small Craft Harbor with water drawn from the Mississippi Sound for 30 minutes to get the fish acclimated to the change in water temperature. All fish were then successfully released in water temperatures between 65 degrees and 67 degrees.

"It was a success," Brainard said. "We could not be happier and we would like to thank everyone who was involved in working with MDMR—Aqua Green, MSU and GCRL—for making this a successful project."

The restocking measure began on Oct. 1 when the 2- to 3-inch long cobia were transported from a hatchery in Miami to the Aqua Green facility where the fish were fed pellets in the holding tanks.

A few days before the deployment to the Fish Haven site, the diet shifted to shrimp and fish.

"We fed the fish twice a day," Nicholls said. "We started out feeding the fish three times a day but cut back to twice a day. We also saw that some (females) were growing faster than others. So we pulled the bigger ones out of the tank and kept those together. We wanted to keep the size as equal as possible.

"To see how they would handle the release, we fed the fish a natural diet and they did great. It showed the fish are hungry and will do fine. They adapted fine."

In terms of survival rates and overall growth rates, Brainard expects the fish to reach the current legal recreational size limit of 33 inches fork length in 18 to 20 months.

"When we got the fish from Miami, they were real skinny, about the diameter of a pencil," Brainard said. "Cobia have an extremely fast growth rate and that's why these fish are great candidates for a stocking program. By June, some of these fish could be between 18 and 22 inches.

"We are not sure on the exact survival rate because this has never been done in Mississippi. But I am thinking the number of predators (sharks) in the water is low during this time of the year and these fish will have the protection of the artificial reefs so it should increase survival rates."

The bottom line? These fish are expected to join in with next year's annual migration run between the Florida Keys and the mouth of the Mississippi River for spawning purposes.

"Right now, these fish will probably go out to one of our offshore reefs," Brainard said. "They should join in with next fall's migration.

"This is our first public/private program. Hopefully, we will be able to do it more often. This program has no down side. It should provide a lot of fun and excellent fishing for Coast fishermen for many years."

The Mississippi Department of Marine Resources is dedicated to enhancing, protecting and conserving marine interests of the state by managing all marine life, public trust wetlands, adjacent uplands and waterfront areas to provide for the optimal commercial, recreational, educational and economic uses of these resources consistent with environmental concerns and social changes. Visit the DMR online at www.dmr.ms.gov.

PHOTO CREDIT: Photos Courtesy of Mississippi Department of Marine Resources

PHOTO CUTLINES:

Photo A: MDMR marine fisheries scientist, Jimmy Sanders, loads cobia on the tanks of the MDMR boat, Fish Haven, at the Biloxi Small Craft Harbor Dec. 9.

Photo B: MDMR marine biologist, Mike Brainard, monitors temperature and dissolved oxygen in cobia tanks before the cobia are released.

Photo C: Cobia are dipped out of tanks for release on Fish Haven 9, a popular offshore artificial reef north of Ship Island.

Contact: Lauren Thompson
Phone: (228) 523-4053

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