Mosquitofish - Environmental Impact

Environmental Impact

Mosquitofish were intentionally introduced in many areas with large mosquito populations to decrease the population of mosquitoes by eating the mosquito larvae. However, most introductions were ill-advised; in most cases native fish had already proven to supply maximal control of mosquito population and introducing mosquitofish has been more harmful to indigenous aquatic life than to the mosquito population. Introductions outside the mosquitofish's natural range, can be harmful to the nonnative ecosystems. Mosquitofish have been known to kill or injure other small fish by their aggressive behavior and otherwise harm them through competition. Mosquitofish are now considered just slightly better at eating mosquitoes than at destroying other aquatic species. However, from the 1920s to 1950's, mosquitofish were a major factor in the eradication of malaria in South America, in southern Russia and in Ukraine. A somewhat famous example of mosquitofish eradicating malaria is on the coast of the Black Sea located near a city in Russia called Sochi. In Sochi, the mosquitofish is commemorated for eradicating malaria by a monument of the fish. In 2008, in some parts of California and in Clark County, Nevada, mosquitofish were bred in aquariums so that people could stock stagnant pools of water with the mosquitofish to reduce the number West Nile virus cases.