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Shepta, E., J. Perkin, K.B. Mayes, M.E. McGarrity, and C.M. Schalk, and C.G. Montaña. 2024. Live-bait industry as a pathway for movement of nonnative and invasive species: Implications for conservation of native Texas fishes. North American Journal of Fisheries Management 44:394–406.

We live in a globally interconnected world. While this brings with it exciting personal and business opportunities, it also comes with some unintended consequences. In the realm of fisheries, globalization has facilitated the movement of fish species over large distances – and quickly. At smaller, regional levels, non-native species introductions are further driven by human activities like aquarium and baitfish releases and purposeful movement of fish from one area to another. No matter the scale or mode of introduction, non-native fish can have large ecological, economic, and human health impacts. 

Understanding the possible pathways of introduction can aid managers in directing efforts to prevent and limit the spread of non-native species. That’s where studies like the one by PhD student Erin Shepta and her collaborators at Stephen F. Austin State University come into play. They interviewed personnel at aquaculture facilities and bait stores to determine what live-bait species were being distributed across the state of Texas. They were particularly interested in two non-native species present in the Brazos and Red River basins, the Gulf Killifish Fundulus grandis and Sheepshead Minnow Cyprinodon variegatus. “Preliminary surveys in the basin by state agencies and other researchers reported the presence of these two invasive species in inland waters. Some hypotheses suggested that these two invasive fish might have been transported as live bait and released into inland basins,” noted Erin.

These two baitfish species are far from the only introduced fishes in freshwaters of Texas. Some, like the Golden Shiner Notemigonus crysoleucas, are well established and not considered species of concern, whereas others like Bigheaded Carp Hypophthalmichthys molitrix and H. noblis are considered highly problematic. Although the state of Texas provides information to the public for identifying non-native fishes (see here), misidentification is still a problem. In their study, Erin found that anglers and bait shop owners tended to refer to many bait fishes as simply “minnows” regardless of the species. Further, Erin adds, “I think sometimes people do not necessarily see these small baitfish as a threat, however in many cases they can really have severe impacts that cascade throughout an ecosystem.”  

The good news is that management strategies appear to be working to limit the spread of non-native fish species in Texas, at least in these targeted river basins. Researchers found that aside from Golden Shiner, the only other non-native species observed in bait shops was Goldfish Carassius auratus. Neither of the two target invasive species were found, a result met with cautious optimism. Unfortunately, Erin and her colleagues reported that many anglers acknowledge releasing unused live bait, not realizing the harm these fish can do to native freshwater ecosystems. Thus, future efforts are needed to help people identify problematic non-native baitfish species and how they can take steps to limit their spread. “From my experience,” says Erin, “anglers want to do what is right for the fish community. They love fishing and want to be sure that their children and grandchildren can continue to fish in the same places they have for their whole life.” 

Interestingly, not all species being cultured and distributed as live bait in Texas were located in the bait stores contacted by Erin and her colleagues during this study. Aquaculture facilities reported 21 species currently being raised for live bait, of which thirteen are considered non-native or only native to certain parts of Texas. The most common species were Fathead Minnow Pimephales promelas, Golden Shiner, and Goldfish. Although Fathead Minnows and the two other invasive species of concern were not found at bait shops included in this study, they may be sold in other areas or may be introduced to ecosystems in other ways. This highlights the importance of exploring distribution pathways across regions and over time to fully understand the live-bait industry and prevent future introductions. 

Often times, the big, flashy fish get the attention. Yet even small species – like many in the live-bait industry – can have a large impact when introduced into new freshwater ecosystems. In Erin’s words, “I think we need to pay better attention to these species and let anglers know that even the little guys can have a huge impact.” Learning more about these “minnows” and other species used for live-bait fishing, where they come from, and where they ultimately go can yield important information about how we can intercept this non-native introduction pathway and implement safeguards that can help prevent or limit their spread.

They may be little, but they can have big consequences. So, when using non-native live bait, be responsible and never release unused fish into the water. 

The full manuscript can be found or downloaded here:
doi.org/10.1002/nafm.10981
List of prohibited non-native fish species in Texas:
https://tpwd.texas.gov/huntwild/wild/species/exotic/prohibited_aquatic.phtml#fish