First Evidence of the Efficacy of Extensive Culture of Longfin Dace as a Replacement for Nonnative Baitfish in the Southwestern United States

Abstract

AbstractThe production, distribution, and sale of live baitfish represent a multimillion dollar industry in the United States. However, production is often limited by the feasibility of culture and few species are profitable. In turn, distribution often occurs well outside of a profitable species’ natural range. Beyond the concern of nonnative species introductions, live baitfish can introduce or spread diseases, resulting in negative ecological consequences. As a result, Arizona Game and Fish Department (AZGFD) wanted to evaluate the feasibility of using a species native to Arizona and southwestern North America that is abundant with a wide regional distribution to meet current commercial needs for small‐bodied baitfish in Arizona. An internal AZGFD team had identified Longfin Dace Agosia chrysogaster as a potential candidate baitfish species due to its low conservation threat, wide distribution in Arizona, and optimal body size (i.e., similar to that of current nonnative baitfish). The goal of this study was to provide a proof‐of‐concept of Longfin Dace culture to meet current small‐bodied baitfish needs in Arizona. To meet this goal, we investigated the efficacy of extensive pond culture of Longfin Dace during 2017–2019 as an option for the replacement of nonnative baitfish. Extensive culture of Longfin Dace resulted in a 21–23‐fold population increase over the course of a year in 2018. Additionally, based on length‐frequency distributions, multiple generations were produced in one year. We conclude that the propagation of Longfin Dace via pond culture to replace nonnative, small‐bodied baitfish is potentially viable. However, the lack of information on carrying capacity and optimized pond characteristics for the pond culture of Longfin Dace should be addressed in the future.