Fish as Mosquito Control Agents in Mangroves

Abstract

The saltwater mosquito, Aedes vigilax (Skuse), is a major vector of Ross River virus and Barmah Forest virus across sub-tropical and tropical Australia, and poses a significant human health risk, particularly in densely populated areas such as South East Queensland and Northern New South Wales regions of eastern Australia. The insect uses saltmarsh and mangrove basin forests as oviposition and larval habitats, and various mosquito control methods exist that target larval stages. Fish, acting as predators of larvae, have routinely been used as a component of mosquito control strategies worldwide. If managed appropriately biological control using fish can be effective, but if mismanaged, biological control can have serious environmental consequences. For example, the release of the Mosquitofish (Gambusia holbrooki (Girard)) for mosquito control in Australian waterways has caused significant ecological damage; G. holbrooki is now a major invasive pest. Nonetheless, mosquito control strategies that include the use of native fish populations in the strategy may be more effective for controlling mosquitoes in mangrove basins than those that do not include native fish. However, little is known of fish populations (both exotic and native) within mangrove basins, and the impact these fish do, and could have on mosquito populations. This research examines the relationship between resident fish and saltwater mosquitoes in eastern Australian mangrove basin forests. It focussed specifically on two mangrove basin sites in the South East Queensland/Northern New South Wales region, and evaluates the potential of resident mangrove basin fish as biological control agents in mangrove ecosystems.