For most of its 2,350 miles, the Mississippi River is channelized by levees. At St. Catherine Creek National Wildlife Refuge, the river and its floodplain are allowed to be themselves. The river’s natural pulse floods thousands of acres each winter/spring and recedes each summer – creating ideal habitat for alligator gar.

For nine years, Kayla Kimmel has been part of a team researching behavior of the enormous, mostly freshwater fish at the refuge in southwest Mississippi.

“I think it’s the coolest fish around,” says Kimmel, a U.S. Fish and Wildlife Service fish biologist based in Baton Rouge, LA. “No matter how many of them I’ve handled or pulled in the boat or wrestled around, it’s impressive every time I have a fish the size of me right next to me.”

Alligator gar typically grow to six feet long, exceed 100 pounds, live 20 to 30 years and don’t spawn until age 10. “These fish have been around for over a hundred million years. I mean, they actually swam with the dinosaurs. To think we have a fish of that magnitude,” says Kimmel, “I feel like what we’re doing is really important.”

Kimmel and team are supported by the Refuge System Inventory and Monitoring Program, the Gulf Coastal Plains & Ozarks Landscape Conservation Cooperative, the Service’s Baton Rouge Fish and Wildlife Conservation Office, Private John Allen National Fish Hatchery and others. Since 2010, the team has tagged more than 60 gar and is using acoustic telemetry to monitor their movements and habitat use at the refuge.

Alligator gar are physostomous (can breathe in air or water). They have bony, armor-like ganoid scales. “I even have some alligator gar earrings made from the scales,” says Kimmel. Native Americans used the scales “all sorts of different ways, from jewelry to arrowheads, because they are diamond- shaped and very pointed.”

Alligator gar are recognizable by their long mouth full of sharp teeth. They are the apex predator in the lower Mississippi River ecosystem. They control other species, including non- native species like carp, and help keep the ecosystem in balance. “We know that everything has an important role,” says Kimmel. “We know they are here for a reason.”

Kimmel and colleagues have learned, or confirmed, that the alligator gar:

  • choose to stay year after year at St. Catherine Creek Refuge even though they could leave via the river.
  • use all habitat types once the water changes floodplain from dry land to aquatic habitat.
  • differ genetically from other populations.
  • are an opportunistic fish that will eat anything in abundance nearby.
  • prefer spawning in 73-degree- Fahrenheit open-but-shallow water containing terrestrial or aquatic vegetation.
“Through the recent research, we have determined that the refuge has three features that meet the alligator gar’s requirements to survive and reproduce successfully: permanent water, seasonal flooding and shallow water across shrubby vegetation,” says St. Catherine Creek Refuge manager Jimmy Laurent. “As managers, we have to ensure that we provide the permanent water that alligator gar need during dry times of the year; fish passage or travel corridors through culverts, canals and pipes; and shallow grassy-scrubby fields for spawning.”

The knowledge gained from the St. Catherine Creek Refuge study can be applied to other alligator gar populations, and the refuge helps stock other waterways throughout the Mississippi River Basin. Each spring since 1999, four or five adult females and a dozen or so adult males have been temporarily relocated to Private John Allen National Fish Hatchery in Tupelo, MS, to spawn before being returned to the refuge. Hatchery manager Ricky Campbell estimates those adults spawn about 60,000 fry annually. They are used to stock bodies of water in Tennessee, Kentucky, Missouri, Illinois and elsewhere.