Fish & Fisheries

Big Fish: Return of the Alligator Gar

Alligator gar are back at Spunky Bottoms. (Left to right) Researcher Nathan Grider of Univeristy of Illinois-Springfield, Doug Carney of Illinois Dept of Natural Resources, Nerissa Michaelsof the Illinois Natural History Survey and Tharran Hobson of The Nature Conservancy.

By Matt Miller, senior science writer

Once they were the river’s top predator: a fish that could reach ten feet or more, with thick armored plates as scales and imposing jagged teeth.

You would see their long, tooth snouts poking out from the river’s surface, gulping air—their adaptation for thriving in warm, deoxygenated water.

Alligator gar.

They thrived in a large swath of mid-western and southern waters, but by the early 1900s, they were already starting to disappear, a trend that continues to this day.

They were declared extinct in Illinois in 1994. But a new restoration and research effort aims to bring back these incredible fish, and help conservationists at other rivers and waters better protect them.

When fisheries biologists Rod Hilsabeck and Trent Thomas of the Illinois Department of Natural Resources decided to return the alligator gar to their state, they knew they needed a perfect location. The Nature Conservancy’s Spunky Bottoms Preserve fit everything they sought.

Formerly farmland, Spunky Bottoms is now 2000 acres of restored wetlands and uplands. It consisted of perfect gar habitat: backwaters and sluggish pools with lots of vegetation. It also was not connected to the adjacent Illinois River, making it easier for researchers to capture and study the fish.

Research is a key component to the reintroduction. Nathan Grider, a master’s student in biology at the University of Illinois-Springfield, is working with Dr. Michael Lemke and partners to study two key aspects of gar restoration.

They are studying how fast gar will grow when restocked into an area. They are also analyzing their diet, and in particular, if the gar will eat (and control) the non-native carp that swim Spunky Bottoms and so many other waters.

This information will help inform gar reintroduction and protection efforts throughout their range.

Gar Wars

Alligator  gar caught at Moon Lake, Mississippi. March 1910
Alligator gar caught at Moon Lake, Mississippi. March 1910


For much of the last century, gar were not protected; they were persecuted. People called them “river pirates.” It was not intended as a compliment.

They accused gar of eating game fish. They accused them of eating humans. (Jeremy Wade, host of the often-sensational River Monsters, could find no evidence this has ever happened).

Facts aside, even fisheries managers in the early part of the 20th century wanted to eliminate alligator gar. They encouraged people to net them, shoot them, dynamite them. Gar died by the thousands.

This relentless persecution, coupled with dams and the loss of backwater habitats, led to a decline and loss of alligator gar across their range. Slow to mature and slow to reproduce, alligator gar cannot sustain heavy mortality; they’re now considered at risk of extinction.

Today, conservationists, anglers and naturalists have found a new and growing appreciation for the fish: a gar renaissance, if you will.

“The attitude towards gar is changing,” says researcher Nathan Grider. “People recognize that the fish are important to the river as a top predator. When even popular game fish like largemouth bass and crappies become too abundant, they get stunted. Predation from gar can keep that from happening. Their presence makes the fishery, and the river, healthier.”

Grider notes that the fossil record for alligator gar in North America goes back more than 3.5 million years, and other gar species swam the waters more than 135 million years ago.

“They literally swam with the dinosaurs,” he says. “They are an ancient lineage that has changed little evolutionarily.”

This new gar appreciation is perhaps best typified by the wonderfully exuberant book by Mark Spitzer, Season of the Gar, a celebration of “the coolest fish that lives.”

“More than any other fish, gar are prepared to fight on, adapt away, and crawl from the muck again,” Spitzer writes.

But they may need some human assistance. Research like that conducted at Spunky Bottoms will play an important role.

The Gar Returns

Researchers sample the stomach contents of an alligator gar. Nathan Grider photo
Researchers sample the stomach contents of an alligator gar. Nathan Grider photo


Spunky Bottoms was stocked with 22-inch-long alligator gar from hatcheries two years ago. Last year, Nathan Grider and his team began capturing them (primarily by netting), measuring them and recording their diets.

Could restocked gar thrive in a restored wetland? Oh yeah. In fact, fish gained as much as 14 pounds in just 17 months.

“It was impressive growth,” says Grider. “We knew the exact age of individual fish, because they came from hatcheries. The fish at Spunky Bottoms grew faster than gar in any reintroduced population.”

That was in large part due to an abundant food supply. The gar ate almost entirely gizzard shad, a small forage fish. As the gar grow, researchers hope they also begin chomping down carp.

“They can certainly get big enough to eat carp,” says Grider. “Further research will help determine if there is a possibility to manage invasive species by reintroducing a top predator into the habitat.”

And what about the alligator gar’s fearsome reputation? Grider and fellow researchers handled a lot of the toothy fish. They also used a technique called lavage, in which the gar’s stomach is pumped with water to flush out its food (the gar is not harmed).

“Lavage is certainly not a pleasant technique, so you might expect the gar would react violently,” says Grider. “That wasn’t the case. You have to respect them. They have the equipment to inflict damage. But none of us were bitten or hurt during our research efforts. Despite the myths and legends, alligator gar are actually pretty docile creatures.”

This is part of an ongoing series on Conservancy fisheries research and how that work intersects with some of the biggest, wildest fish in freshwater.

Nathan Grider and Ron Hilsabeck hoist "the coolest fish that swims."
Nathan Grider and Ron Hilsabeck hoist “the coolest fish that swims.”

Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.

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  1. I am curious to see their impact on nesting waterfowl, specifically ducklings. As most of us know, small bodies of sheet water with adjacent upland cover is prime nesting habitat for ducks and geese. The last thing they need is an additional predator. What are Your thoughts?

  2. Hi Dale,

    While there have been few published studies on alligator gar, most of them have been on diet due to the concerns of sportfish consumption. Most literature agrees that feeding behavior is “opportunistic,” meaning they will eat whatever prey ventures close enough. The most abundant prey-sized fish in the environment is typically what is found in the stomach. There have been a few mentions of birds in their stomachs. In 1942, E. C. Raney published “Alligator Gar feeds upon Birds in Texas,” in Copeia. He explained that alligator gar caught by angling (not during research) contained large birds in their stomachs. He also told a story of someone witnessing a water turkey (Anhinga anhinga) being eaten and ducks once shot by hunters. Again, these are just stories and not well documented. I am not aware of any waterfowl/birds found in stomachs during scientific research, except for one chicken (used as bait) that likely came from a crab line. Fish seem to be their prey of choice. However, they may eat waterfowl on occasion and given the opportunity. Given the alligator gars small numbers throughout their range, they are probably not a significant source of predation on nesting waterfowl.

  3. I’m a big fan of gar, both as a fisherman and a lover of interesting animals. The idea that there could again be alligator gar right here in Illinois is very exciting. This is a story I will be following closely. Maybe some day I’ll be able to take my daughters fishing (catch and release, of course) for gator gar in their home state!
    Keep up the good work.

  4. Nice article. I never knew of those fish until I moved to S. Florida in 1980. The fish are common in Everglades National Park, but I never knew they could get as big as the monster pictured in B&W in the article. Neither did I know the fish were endangered in any way. I guess it shows you can learn some thing new every day. Those fish sure would chomp on Asian carp, as well as snakeheads and almost any other fish they could catch.

    1. I don’t think the gars in south Florida are alligator gars. I think their historic range was inland along the central Gulf coast and up the Mississippi Embayment.

  5. Will the fisheries biologists Rod Hilsabeck/Trent Thomas or the Illinois Department of Natural Resources be providing the spunky Bottoms Alligator Gar Study finding’s to the U.S. EPA Great Lakes Advisory Board. This could be pivotal in the development of the new Great Lakes Restoration Initiative (GLRI) Action Plan who’s current main focus is the Asian Carp threat to the Great Lakes.

    The growth rates are promising for Northern Water’s.

    1. I think it was pretty interesting reading about these phenomenal creatures of the wet lands. It’s pretty unique how we first went after them to saving them if we made them extinct the food changed would be very screwed up.

  6. It would be interesting to see if the Gar would survive the cold Michigan waters. Lake Michigan is being overrun with Asian Carp. It will soon begin to affect sport fishing and economical impact.

  7. A pound of prevention..using the Asian carp problem as an example, the federal government must take a more aggressive approach to prohibit the importation, legal and otherwise, of foreign species. Think of the dollars and effort being put forth trying to solve a problem that was caused by fish farms importing the fish to be used for the only purpose of cleaning the ponds. Then there is the giant snake problem in the Everglades and the Emerald Ash Borer due to poor oversight by the importing companies…Vigilence must be increased and given a higher priority.

  8. This week I caught the prettiest fish in my 65 year old age life. An small alligator gar with a white belly dark green body with spiral markings on its tail. Wish I’d taken a picture before I released it back in the Meramec River near St. Louis.

  9. I am just turning 73 years old. When my father was a ThD student (and Public Relations Director) at New Orleans Baptist Theological Seminary 1950-54, we fished around New Orleans, often in what was considered brackish water, and we encountered this fish fairly often. Before my teens, I caught a 13 1/2 pounder, and a 27 pounder, both at Salt Bayou, east of Slidell, just north of New Orleans. It was as if I caught a Leviathan both times. I also remember seeing a big one in a mosquito-infested canal near Lafitte, south of New Orleans. He looked to be five or six feet long, and my father estimated him at about 65 pounds.

    My impression is that since then, the size of these “monsters” has declined, reason being that they seem to be territorial in fairly small areas, so that they are “a big fish in a small pond,” to the point that they are fairly easily zeroed in on, particularly if they happen to be large. That is why, I think, we no longer see anything at all the size of that 1910 fish. The experience of seeing (and hearing) one of these things break the top of the water is unlike anything else in their habitats. It is like an alligator, only alligators to my knowledge don’t ordinarily break the water so powerfully like that unless they are hooked (on one of those “Cajun” TV shows).

    My son, Bryan Bennett, made a name for himself down here in Gulf Shores, Alabama, fishing offshore in the Gulf and on the Gulf State Pier here. His love was the big saltwater fish — Ling, King Mackeral, etc. Now that he is gone, I wish I had shown more interest in that love of his, but I have always been more taken with fresh water, whether it was fishing or aquarium involvement. The Gar, to my knowledge, is primarily a fresh water fish. Incidentally, Bryan was witness to a 100 pound Alligator Gar cruising along the beach going east towards the Gulf State Pier for perhaps a mile or two or three, and it was caught on the pier. So they do get out of freshwater occasionally.

    The arcane appearance of the Alligator Gar has always captivated me, as has that of the Bowfin, and also the Coelacanth. As a kid I actually caught a 7 pound Bowfin (Grinnel, Cottonfish, Mudfish, Choupique) north of New Orleans in the Honey Island Swamp area near Pearl River. It was two feet long, exactly. Like Gar, those fish can live out of the water for some time. It is as though you are dealing with fish that slowly emerged from the swamp water to become land animals — these particular ones just never themselves quite left the water for good. Evolution — this certainly comes to mind.

    If the Gar lived during the time of the Dinosaurs, probably he lived and they didn’t because when the great Asteroid hit off the Yucatan Peninsula 65 million years ago, the Dinosaurs on land had no way of surviving the resulting conflagration and perhaps those below water didn’t have the leathery skin of the Gar. (Layman’s speculation, I assure you.) What is left is an fish similar in appearance to the Alligator. And when he suddenly breaks the water in a relatively small body of water, he is like a creature out of time and out of place. It is as though we are witness to a prehistoric adventure in him or her, unlike any other adventure of the present day.

  10. I just got done reading both of Mark Spitzer’s books. Probably the best eco books I have come across, both funny and very enlightening. My Grandparents farm on the boot heel of Missouri along the St Francis river had many of these fish as my Dad recalled he saw as a boy. I’m making a trip there to see if I can see them as Missouri has been active reintroduction. Great article and programs.

  11. What DC voltage was used in the eradication program during the last century ships with on board generators about the 1920 ‘s do you have any general information about the practice please

  12. In 1953, in Gainesville Florida, my uncle brought a large gar back from a spear fishing trip. He handed a butcher knife to me and offered $1 is I could butcher it. I tried but the tough scaly hide was so tough that my energetic attempt at butchering failed.