Rid-a-fish: A new tool for eradication of aquatic nuisance species

Authors: Ward, David

Year: 2017 (xlix)

Abstract

The continued decline of native fish in the southwestern United States is largely attributed to negative interactions with introduced fishes Attempts to remove nonnative fish from areas with natives are common, but success is limited because very few tools are available for managing invasive aquatic species A new ammonia-based product called Rid-a-fish utilizes the relationship between pH and ammonia toxicity to eliminate gill breathing organisms from water At high concentrations, ammonia is known to be toxic to a wide variety of aquatic species and yet ammonia is the natural product of fish metabolism and is naturally present in the environment at low levels Natural bacteria in the environment rapidly convert ammonia to non-toxic nitrate which is utilized by plants Rid-a-fish has been shown to be effective at eliminating unwanted fish, crayfish, snails and mussels in laboratory settings, but needs evaluation on larger scales in natural systems We evaluated the effectiveness of Rid-a-fish for removal of invasive green sunfish Lepomis cyanellus in a 1,000 cubic meter pond below Glen Canyon Dam at Lees Ferry A second field trial evaluated the effectiveness of Rid-a-fish for removal of mosquitofish Gambusia affinis in 20 replicated 3,000-liter stock tanks and in an 800 cubic meter pond on the El Coronado Ranch in Southern Arizona In in all cases this new tool was effective at eradicating the populations of unwanted fish Although further field trials are needed, these initial tests indicate licensing and registration of this new fish removal tool may be warranted