News Release Distributed 05/16/14
[Image: Phil Elzer]
[Image: Christopher Green]
BATON ROUGE, La. – Researchers from the LSU AgCenter and students from Nicholls State University recently collected alligator gar at the LSU AgCenter Aquaculture Research Station in Baton Rouge in an effort to improve the fish populations in areas where they are no longer found.
Christopher Green, the lead researcher on the project at the station, is working with biology students at Nicholls to address the spawning behavior of the fish. And for the past four years, Green has been looking at ways to keep the alligator gar a viable species in southern Louisiana and other parts of the Mississippi River.
Green said the main problem that plagues the alligator gar is coming from man-made changes to its environment.
“These fish are accustomed to laying their eggs in flooded backwaters on the Mississippi, Arkansas and Ohio rivers,” Green said. But channeling and other diversion projects are making most of the natural nesting places unavailable.
Green said during the spring floods when the waters go over the river banks, these fish would normally lay their eggs in these floodplains. The eggs would quickly hatch, and the fingerlings would follow the current as the waters recede.
“What we’re doing here with the students from Nicholls is recapturing the fish in this pond where they were tagged and released in prior years,” Green said. “We’re weighing them, scanning them for identity and giving them a hormone shot to force them to ovulate.”
With help from Nicholls State’s biology graduate students, the fish are transferred to another pond with a spawning substrate that simulates grass in flooded fields where they will lay their eggs in the next 24 to 36 hours, said Nicholls president Bruce Murphy, who also helped in the transfer process.
“This is a good opportunity for our students to get some hands-on experience with a very beneficial project,” Murphy said.
“When they asked if I wanted to come for the spawning project, I was excited,” Murphy said. “We’ve pulled some out weighing as much as 65 pounds.”
The alligator gar is unique compared to other types of gar. This species specifically requires a flooded habitat while other gar can spawn in pools and ponds. Alligator gar are still found in the floodplain and marshes of Louisiana, but in the past have been all the way up in the Mississippi River, Green said.
Phil Elzer, LSU AgCenter program leader for animal sciences and natural resources, said a formal agreement between the LSU AgCenter and Nicholls State University on this project is good for the people of the state.
“Alligator gar is a species of concern by the U.S. Fish and Wildlife Service. They are an ancient species that has been around since the time of the dinosaurs,” Green said. “They arose about 125 million years ago.”
Erosion control projects that have been put in place to control flooding have put pressure on these fish, Green said.
So a lot of areas that did have these fish don’t have them any longer, he said. “It’s like they used to be in Illinois and Ohio, but now they are not.”
Green said the term for this situation is extirpated, which is not to say that they are extinct. It’s just we don’t see them in those areas anymore.
Green said the young that will be hatching from this spawn will be shared with other states like Mississippi for comparability studies.