Scientists Are Releasing 7-Foot River Monsters Into Carp-Infested Waters — Results Are Coming In

America spent a century trying to wipe out the alligator gar. It shot them from riverbanks and blew them apart with dynamite, convinced this prehistoric giant was destroying the fish anglers wanted. The last wild alligator gar in Illinois was caught in 1966. About seven feet long. Around 130 pounds. It is still the state record, and for decades afterward the biggest predator in those rivers was simply gone. Then the carp arrived. Silver carp reached Illinois waters in the 1990s and found a river with nothing big left at the top. Today they can make up as much as 70% of all the fish in the Illinois River by weight. America has answered with a $1.15 billion barrier project at Brandon Road, record-breaking net hauls of 750,000 pounds in ten days, and a $600,000 federal campaign to rename the fish "copi" so people might eat it. And quietly, state biologists have been putting the alligator gar back. More than 21,000 of them since 2010, sometimes at locations that were never announced, because the prejudice that erased this fish is still alive. But can the gar actually stop the carp? Three biologists give three different answers, and the honest one is uncomfortable. This is the story of two fish, and how America got both of them wrong. Sources and further reading: Huge, once-hated fish now seen as weapon against Asian carp (AP / CBS News, 2016) https://www.cbsnews.com/news/huge-once-hated-fish-now-seen-as-weapon-against-asian-carp/ Return of the Giants: The reintroduction of alligator gar to the Cache River (Outdoor Illinois Journal, 2025) https://outdoor.wildlifeillinois.org/articles/return-of-the-giants-the-reintroduction-of-alligator-gar-to-the-cache-river Alligator Gar Reintroduction program (Illinois Department of Natural Resources) https://ifishillinois.org/Pages/Resources/Programs/GarReintroduction Setting the record straight on alligator gar and invasive carp (Michigan Sea Grant, 2016) https://www.michiganseagrant.org/blog/2016/09/01/setting-the-record-straight-on-alligator-gar-and-invasive-carp/ Study of slowly evolving "living fossils" reveals key genetic insights (Yale News, 2024) https://news.yale.edu/2024/03/04/study-slowly-evolving-living-fossils-reveals-key-genetic-insights Extremely slow evolution in "living fossils" could inform human health (University of Minnesota, 2024) https://twin-cities.umn.edu/news-events/extremely-slow-evolution-living-fossils-could-inform-human-health Ranger Rick: A Garish Origin Story (Solomon David, The Nature Conservancy) https://blog.nature.org/2020/12/14/ranger-rick-a-garish-origin-story/ Silver Carp species profile (USGS Nonindigenous Aquatic Species) https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=549 Silver Carp (U.S. Fish and Wildlife Service) https://www.fws.gov/species/silver-carp-hypophthalmichthys-molitrix IDNR concludes record-breaking invasive carp removal effort on the Upper Illinois River (2023) https://icrcc.fws.gov/news/idnr-concludes-record-breaking-invasive-carp-removal-effort-upper-illinois-river From "Asian carp" to "copi" (AP / PBS NewsHour, 2022) https://www.pbs.org/newshour/nation/a-copi-fillet-illinois-hopes-new-name-for-invasive-carp-will-convince-diners Brandon Road Interbasin Project (U.S. Army Corps of Engineers) https://www.lrd.usace.army.mil/Missions/Projects/Display/Article/4457609/brandon-road-interbasin-project/ Why Missouri is stocking thousands of alligator gar (KZIM, 2026) https://kzimksim.com/2026/08/25/the-bootheels-new-guard-why-missouri-is-stocking-thousands-of-alligator-gar/ All footage and images used for educational and commentary purposes.