Students learn about fish spawning
Published 10:17 pm Thursday, December 17, 2009
Destroyer of Light and Swagg slipped into the murky waters of the Mobile-Tensaw, familiar habitat to the ancestors of this mottled crew that eventually totaled 10.
With the help of the Alabama Department of Conservation and Natural Resources’ Wildlife and Freshwater Fisheries Division, students from the Fairhope High School aqua science class released 10 alligator gar, including the aforementioned pair, they had reared from hatchlings back into the habitat from whence the species came.
Dave Armstrong, District 5 Fisheries Supervisor with Wildlife and Freshwater Fisheries Division (WFFD), said Megan O’Neill of Fairhope High approached him about using a species native to southwest Alabama for the class instead of commercial species like tilapia or catfish.
“We talked about this last year and discussed largemouth bass and bream,” Armstrong said. “I’m not sure we even talked about alligator gar. As it turned out, the timing (of the alligator gar spawn) was perfect for her class. When we’re working with bass and bream, we pick them up, spawn them and get them back out in late spring or early summer. That’s when the kids are out of school. These gar are such late spawners that we didn’t start the stocking process until late July and early August, so we kept back about a dozen fish for her. These are hardy fish and she only lost one during this whole time, five months.”
The Fisheries Section started collecting alligator gar brood stock in 2005 with large-panel gill nets. The spawning process has only been completed in 2007 and 2009.
“The first year, our whole learning curve as far as the spawning process was with Ricky Campbell at Private John Allen National Fish Hatchery in Tupelo, Miss.,” Armstrong said. “Our first spawn was at Tupelo and this year Ricky came down to Marion Fish Hatchery (in Perry County) and we did all the spawning there.” A small portion of the fertilized eggs were also transferred to Warm Springs National Fish Hatchery in Georgia. Those fish were raised out and returned to Alabama for restocking as well.
The meticulous process of spawning involves the injection of the brood stock, all 52 inches or longer, with a hormone to promote the release of the eggs and sperm. Both are extracted, treated and mixed before being placed in carefully controlled tanks and then into holding ponds. When the hatchlings are large enough, they are transferred to restocking sites. The only other restocking site, other than that connected with the Fairhope High program at Meaher State Park, has been at Claiborne Reservoir on the Alabama River.
Armstrong said in the late 80s and early 90s there were a handful of people fishing commercially for gar. One of the fisheries biologists bumped into some of the gar fishermen and discovered their daily catch had been 800 pounds. Because gar was listed as a non-game fish, it was unregulated. ADCNR officials quickly realized limits were needed and established a two-fish-per-angler daily limit.
“That pretty much nipped the commercial harvest in the bud,” he said. “In 2000, we decided we needed to do a population dynamics study because there had been quite a bit of interest in the Southeast. States like Louisiana and Mississippi were looking at their stocks and Florida couldn’t even find any. There are six states where they’re extinct now. They once ranged all the way to the Ohio River.”
Allyse Ferrara, who was at Auburn at the time, was able to do work on her doctoral dissertation through a population dynamics study on alligator gar. She found that alligator gar females do not reproduce until they are 10 or 11 years old, and males not until they are about 8. Her conclusions and subsequent public hearings led to a reduction in the daily bag limit to one per angler.
The current range of the alligator gar in Alabama is pretty much limited to the Mobile-Tensaw Delta to Claiborne dam on the Alabama River and Coffeeville dam on the Tombigbee. There is also evidence of fish in Claiborne Reservoir, and that’s one the reasons gator gar have been restocked in that impoundment.
“We need an area like that in case we have another Ivan and Katrina (hurricanes of 2004 and 2005) back to back,” Armstrong said. “We had a lot of dead alligator gar reported after the hurricanes. That was probably because the water was anoxic (devoid of oxygen) because of all the plant matter that got blown into the water.”
While some sports fishermen may question why alligator gar, which grow as big as 150 or so pounds, are being restocked, Armstrong said these fish won’t have any impact on the sport fish population. WFF is also currently undertaking an effort to genetically enhance the Delta-strain largemouth bass population through a stocking program.
“While they may eat an odd bass or crappie occasionally, the diet studies that have been done show these gar eat really big fish,” he said. “They eat buffalo, carp and really big gizzard shad. Nothing eats buffalo or carp but a gator gar. In Missouri, they’re restocking hoping the gar will reduce the non-native Asian carp.”
Armstrong said the Fairhope High program should promote an interest in native fish.
“Anybody can raise tilapia and catfish,” he said. “We wanted to give the students a conservation message about raising native species and something native to the Delta, kind of a hallmark of this area.”
O’Neill said the alligator gar project fits in with many current science issues like the health of native species and aquaculture.
“Our students learn to test water quality and they’re responsible for the growth of these fish,” she said. “These fish are the students’ fish and they are responsible for them. They learn about aquaculture species, fish health and disease, water quality and all the aspects of aquaculture.
“We felt the alligator gar, being a native species, would be perfect for our program. Because the numbers are dwindling, we wanted to be able to raise these fish and release them into the Delta.”
O’Neill has participated in the ARMADA Project, a National Science Foundation grant, for two scientific study excursions. In 2007 she went to the Arctic aboard a Spanish vessel to study geology. Her latest adventure was to the Antarctic with a group of scientists from Duke University, the University of Maine and University of Alaska to study ice fish and they tagged a whale in the process.
“I’m definitely about getting out in the field and learning science,” she said. “I continue to learn myself. I think that’s the most important thing is to not stop learning so I can help my students.”
O’Neill said the students have realized a great deal of enjoyment raising the gar, naming many of them along the way.
“They’ve had a lot of fun,” she said. “We hope this is a long-term association and we’re looking at probably some Delta bass next. We look at this as a huge success and a learning process, as well.”