Managing mosquitoes associated with constructed and rehabilitated wetlands is a major concern. A key factoring influencing mosquito production is aquatic vegetation. Here are the key slides from a presentation from ‘Managing constructed wetlands and water plants’ workshop at Sydney Olympic Park, NSW, Australia.

1. Mosquitoes in Constructed Wetlands
Dr Cameron Webb
Department of Medical Entomology
Pathology West – ICPMR Westmead, Westmead Hospital
Marie Bashir Institute of Infectious Diseases and
Biosecurity, University of Sydney
Email: Cameron.webb@health.nsw.gov.au
Twitter: @mozziebites

3. RRoossss RRiivveerr && BBaarrmmaahh FFoorreesstt
• Most common in Australia (~5,000 cases/pa)
• Symptoms:
 Not fatal but rash, fever, joint pain,
polyarthritis
• Complex ecology, in different regions:
 Seasonal & geographic variation
 Different vectors
• Marsupial hosts? Bird hosts? Human hosts?

5. Water Sensitive Urban Design
 Integration of water management into
urban planning and design
 Urban developments contain a suite
of water conservation strategies
 Constructed wetlands
 Bioretention swales
 Raingradens
 Rainwater tanks
 Mosquito risk variable
 Design, construction, installation and
maintenance issues can increase the
mosquito risk

6. CCoonnssttrruucctteedd WWeettllaannddss
 Stormwater retention & treatment
 Wildlife conservation
 Change local mosquito diversity
 Change in local environmental
drivers of mosquito populations
 Change in reservoir hosts
 Wetland design & maintenance
 Water quality, depth & flow rates
 Edge structure and slope
 Vegetation zones
 Predators
 Well funded management plan

7. Wetlands support diverse habitats

8. Vegetation and mosquito risk?
 Stem density: multiple stems increase refuge
 Growth density: more plants per area
 Invasiveness: create monoculture
 Plant litter: increase refuge & organic content
 Deep water tolerant: potentially greater coverage
 Floating plants: density & root mass provides refuge
 Terrestrial plants: grow into water & provide refuge?
 What plants are required to meet wetland objectives

9. Estimated mosquito risk associated with aquatic vegetation
Plant group Plant name
Mosquito Risk
High Med Low
Emergent Alisma spp. (e.g. Water Plantain) +
Sagittaria spp. (e.g. Arrowhead) +
Cyperus spp. (e.g. Giant Sedge) +
Typha spp. (e.g. Cumbungi) +
Phragmites spp. (e.g. Common Reed) +
Bolboschoenus spp. (e.g. Clubrush) + +
Eleocharis spp (e.g. Common Spikerush) +
Persicaria spp. (e.g. Slender Knotweed) +
Floating Azolla spp. (e.g. Water Fern) +
Eichhornia spp. (e.g. Water Hyacinth) +
Lemna spp. (e.g. Duckweed) +
Potamogeton spp. (e.g. Pondweed) +
Salvinia spp. (e.g. Salvinia) +
Ranunculus spp. (e.g. Buttercups) +
Based on Knight et al. (2003) Ecol. Engineering 21:211-232 & Sainty and Jacobs (2003) Waterplants in Australia

10. Guidelines for constructed wetlands
 Provides assistance to local
governments on assessing mosquito
risk associated with wetlands
 Provides background on mosquito
and mosquito-borne disease risk
 A framework for decision making
 Highlight wetland projects that may
require more detailed assessments
and the engagement of consultants to
develop a site-specific plan

12. WWeettllaanndd RReehhaabbiilliittaattiioonn
 Accompany development
 More mosquitoes?
 Restore tidal flooding (coastal)
 Environmental flows (inland)
 Long-term & short-term issues
 Change in local environmental
drivers of mosquito populations
 Change in reservoir hosts
 Mosquito management?
 Are these “natural” habitats?

13. A Regional Apppprrooaacchheess ttoo MMoossqquuiittoo RRiisskk

14. Thank you
Follow me on Twitter @mozziebites
Learn more about my research:
http://cameronwebb.wordpress.com