Healthy ecosystems provide a variety of ecosystem services to humans, including provisioning (food, water, fuel, and shelter), regulating (climate control, disease suppression) and cultural services (recreation and wellbeing). When biodiversity is adversely affected by human activities such as agriculture, CO2 emission, and urbanisation, ecosystem services (including disease regulation), can fail. Directly or indirectly, the maintenance of biodiversity can prevent the emergence of arbovial diseases as major public health problems.
In Australia, the most common vector-borne disease is Ross River Virus (RRV), carried by a variety of mosquitoes including the halotolerant Aedes camptorhynchus. In healthy, biodiverse, freshwater ecosystems that contain predators and competitors, Ae. camptorhynchus numbers are kept low; but when biodiversity is lost through for example dryland salinisation, mosquito populations can boom and increase the risk of RRV outbreaks (Carver et al. 2010). In addition, it is possible that a concurrent loss in vertebrate reservoir biodiversity increases the percentage of mosquitoes infected because of a decreasing ‘dilution effect’ (sensu Ostfeld & Keesing 2000).
In attempting to determine if this relationship between biodiversity loss and increased risk of RRV is generalisable to other anthropogenic environmental disturbances, we are now examining the effect of urbanisation on the epidemiology of RRV (Flies, this conference). If confirmed, the existence of such a relationship would support the already increasing evidence that there are health benefits from including the maintenance of biodiversity as an urban planning goal.