Control of freshwater fish with chemicals

Fish toxicants have been used for nearly 60 years by sport fishery managers to remove predaceous or competing fishes from gamefish waters. The reclamation of lakes and streams by poisoning unwanted fish is considered to be one of the better management tools, and the demand for reclamations is increasing as more waters come under intensive management. Many chemicals have been tried as fish toxicants, but the insecticides rotenone and toxaphene have been most widely used despite their disadvantages of non-selectivity between wanted and unwanted fishes, persistence in water, and toxic effects on aquatic invertebrates. Research In the past 20 years led to the development of toxicants specific to fish and formulations better suited to aquatic applications. Further progress is noted in the search for safe, more selective controls for pest fishes in the wide variety of aquatic environments