Mosquitoes, constructed wetlands, urban design and climate change: Some workshop resources

wetlandswalkThis is a short summary of resources supporting my lecture on “Mosquito Management, Climate Change and Urban Design” at Environmental Health Association of NSW Public Health School on Monday 24 March 2014, Sydney Olympic Park.

The nuisance-biting and potential transmission of pathogens by mosquitoes in coastal Australia is a concern for local authorities. Increasingly so at the fringes of our cities. There has been something of a resurgence in Ross River virus this year with the virus isolated from mosquitoes collected at a number of locations across NSW.

While it is difficult to determine exactly why this resurgence has been experienced this year, there are a number of factors that can predispose a region to elevated risk. An understanding of local risks are important and regionally specific mosquito management plans (i.e. the “Living with Mosquitoes” strategies) have been developed in the Hunter and Mid North Coast as well as the Central Coast regions of NSW. These documents provide an overview of mosquito fauna, identify key pest and vector species and their associated habitats and respective environmental drivers of abundance. With the provision of information on mosquito management strategies, local authorities can develop regionally specific responses to seasonal pest and public health risks.

wetlands_sydneyparkAs well as providing strategies for local authorities on mosquito control activities, they also provide opportunities to shape future mosquito-borne disease risk through urban design. While efforts are underway to better manage urban water conservation through Water Sensitive Urban Design, perhaps “Mosquito Aware urban Design” should also become an important component of new residential developments? There appears to be growing evidence that how we manage water in our cities will have just as great an impact of future mosquito-borne disease risk as climate change.

Despite the claims that often accompany discussion of the health impacts of climate change, Australia is unlikely to see a dramatic increase in “exotic” mosquito-borne disease. There may be regional increases in Ross River virus and Barmah Forest virus with changes in rainfall, temperature, extreme weather events and sea level rise but, equally, some regions may see a decrease. Understanding the complex interactions between mosquitoes, wetlands, wildlife and pathogens is required to fully understand these “endemic” risks. Perhaps with regard to “exotic” risks associated with viruses such as dengue and chikungunya, it will be the introduction of exotic mosquitoes, such as the Asian Tiger Mosquito, Aedes albopictus, that will pose the greatest risk.

Monitoring mosquitoes and the pathogens they're carrying will remain critical in assisting the assessment and management of public health risks in Australia

Monitoring mosquitoes and the pathogens they’re carrying will remain critical in assisting the assessment and management of public health risks in Australia

There are many things Environmental Health Officers with local council or health authorities will need to consider when assessing local mosquito risks but the basis for all their decisions should come from a well designed and resources surveillance program. There are new technologies available for both the collection of mosquitoes as well as detection of pathogens. However, an understanding of regionally important pathogens, mosquitoes and their local habitats is critical.

The slides of my presentation are below:


Some key resources were included in the presentation and are linked to below.

For guidelines on the risk assessment of potential mosquitoes and mosquito-borne disease associated with constructed wetlands in western Sydney, see this document developed by Western Sydney Local Health District Byun & Webb – Guidelines for mosquito risk assessment and management in constructed wetlands – WSLHD – Nov 2012

There are two chapters contained within the recent eBook (free to download) “Workbook for Managing Urban Wetlands in Australia” that provide an understanding of mosquito and mosquito-borne disease risk more generally in association with freshwater constructed wetlands and estuarine rehabilitated wetlands.