SNAPPER BONANZA

Two Ways To Spawn Snapper: Artificially and By Creating Habitat

Editor's Note: David Maus is a research sssociate who was brought in by the Marine Resources Division of Alabama's Department of Conservation to design and build the brood stock systems to hold and breed red snapper in an artificial environment. He has masters degree in aquaculture and 20 years experience in commercial production of marine fish, primarily red drum, black drum and spotted seatrout. He's built and run a farm that produces and raises over 1 million red drum fingerlings per year and produces 300,000 or 400,000 pounds of marketable size fish per year.

In the past, to get brood stock, Alabama's Marine Resources Division (AMRD) has caught wild snapper, brought them into the laboratory and artificially spawned them by giving them hormonal injections. "One of the problems with artificially inducing the spawn," Vernon Minton, the director of the Marine Resources Division for Alabama's Department of Conservation, mentions, "is that we have a very-narrow window to catch the snapper and get them to spawn. May and June are our best months, and sometimes July. During these two primary months, the size of our facility only allows for four or five spawns. We catch the fish, induce them to spawn and then begin to work with the spawned eggs, a process that takes about 10 days. So we haven't been able to get the number of fish we need and produce the number of eggs and small snapper that we need for major restocking effort."

To solve this problem, a group of fisheries scientists from Auburn University, headed by Dr. Ron Phelps and including David Maus came to the Mariculture Center and developed artificial habitat for the snapper. As Maus explains, "To build an artificial habitat to cause the red snapper to spawn every six months instead of every year, you have to be able to control the photo periods, the temperature and the water quality, because if you don't have good water quality, you stress the fish. If you can keep fish from being stressed, they'll have more energy to put into growth and reproduction. The artificial habitats are 6-feet deep with dish-shaped bottoms and have 12-foot diameters. The tank has a water-circulation pump and a bio-filtration system. It also has a heat pump for temperature control. The lighting system inside the habitat simulates sunrise and sunset as well as the phases of the moon. Each tank is separate from the other and has a hood over it to keep out light. In these artificial habitats, scientists can control the fish's year and cause the snapper to spawn when the scientists want them to spawn. The big advantage to the artificial habitat form of spawning, as opposed to chemically-induced spawning, is the artificial habitat spawn is more natural. The eggs spawned and fertilized at that time have a much-higher survival rate than the eggs spawned using chemical inducements." Because the researchers control all the natural conditions in the artificial habitats, the snapper think it's time to spawn. By keeping male and female snapper in the artificial habitat, when the females produce eggs and prepare to spawn, the males have sperm also ready to fertilize the eggs.

"One of the problems that AMRD has encountered is that not all snapper are compatible or have the same personalities," Minton explains. "Scientists have to make sure that the group's dynamic in the artificial habitat is conducive to a successful spawn. Usually if a snapper in the 1000-gallon tank doesn't get along with the other snapper, we remove the bad snapper." Maus, with his extensive background with commercial fish hatcheries, is trained to observe fish behavior and make sure that all the fish in the tank like each other. Maus says that he can tell which snapper are happy and has learned, "happy snapper are much more likely to get off a successful spawn than unhappy snapper."

To learn more about this program at the Marine Resources Division, e-mail Minton at rvminton@gulftel.com, and you also can visit www.dcnr.state.al.us/mr/cpmc.htm on the Web.

TOMORROW: THE FUTURE OF RED SNAPPER