Anthropogenic Ecological Change and Impacts on Mosquito Breeding and Control Strategies in Salt-Marshes, Northern Territory, Australia

• Published in: EcoHealth Vol. 9; no. 2; pp. 183 - 194
• Main Authors: Jacups, Susan, Warchot, Allan, Whelan, Peter
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01.06.2012; Springer Nature B.V
• Subjects: Animal Ecology; Animals; Anthropogenic factors; Aquatic insects; Artificial wetlands; brackish water; breeding; breeding sites; Culicidae; Disease transmission; Drainage; drainage channels; dry season; Ecosystem; Ecosystems; Environmental Health; Environmental impact; Environmental Monitoring - methods; Environmental restoration; Insect Vectors; Mangroves; Medicine; Medicine & Public Health; Microbiology; Mosquito Control - methods; mosquito-borne diseases; Mosquitoes; Mud flats; nontarget organisms; Northern Territory; Original Contribution; pests; plague; Public Health; Residential areas; risk; runoff; Salt marshes; Seasons; Stormwater; Swamps; Vector-borne diseases; vegetation; Viruses; Water and Health; wet season; Wetlands; Northern Territory; Australia; anthropogenic change; ecology; Murray Valley encephalitis virus; Ross River virus; habitat modification; arbovirus
• DOI: 10.1007/s10393-012-0759-5
• ISSN: 1612-9202

Darwin, in the tropical north of Australia, is subject to high numbers of mosquitoes and several mosquito-borne diseases. Many of Darwin’s residential areas were built in close proximity to tidally influenced swamps, where long-term storm-water run-off from nearby residences into these swamps has led to anthropogenic induced ecological change. When natural wet–dry cycles were disrupted, bare mud-flats and mangroves were transformed into perennial fresh to brackish-water reed swamps. Reed swamps provided year-round breeding habitat for many mosquito species, such that mosquito abundance was less predictable and seasonally dependent, but constant and often occurring in plague proportions. Drainage channels were constructed throughout the wetlands to reduce pooled water during dry-season months. This study assesses the impact of drainage interventions on vegetation and mosquito ecology in three salt-marshes in the Darwin area. Findings revealed a universal decline in dry-season mosquito abundance in each wetland system. However, some mosquito species increased in abundance during wet-season months. Due to the high expense and potentially detrimental environmental impacts of ecosystem and non-target species disturbance, large-scale modifications such as these are sparingly undertaken. However, our results indicate that some large scale environmental modification can assist the process of wetland restoration, as appears to be the case for these salt marsh systems. Drainage in all three systems has been restored to closer to their original salt-marsh ecosystems, while reducing mosquito abundances, thereby potentially lowering the risk of vector-borne disease transmission and mosquito pest biting problems.