Some Persuasive Facts for protecting biodiversity
Laura Heady, NYSDEC Hudson River Estuary Program and Cornell University – 2009
West Nile Disease and Wetlands
There is a common misconception that wetland habitat protection will lead to increased numbers of mosquitoes and increased threat of contracting West Nile Disease. The principal transmitter of the West Nile Virus is the northern house mosquito (Culex pipiens), which breeds in the standing water that collects in rain barrels, clogged gutters, flower pots, catch basins, discarded tires, and other artificial containers. The highly organic nature of this stagnant water, along with a lack of predators, provides optimal conditions for the develop-ment of larval mosquitoes. Naturally-occurring, healthy wetlands, on the other hand, have a diversity of predators that eat mosquito larvae; some invertebrate predators include diving beetles, backswimmers, water striders, and dragonfly and damselfly larvae. Certain species of birds, fish, and amphibians also feed on larval and adult mosquitoes. In addition, water levels in healthy wetlands fluctuate regularly, which deters Culex mosquito breeding. Research from North Dakota found many more mosquitoes in degraded wetlands than in higher quality wetlands. (Chipps et al. 2006) In Massachusetts, when the Essex County Mosquito Control Project restored a 1,500 acre wetland, the mosquito population dropped by 90 percent. (Williams 1996) This is a good example of biodiversity providing a human-health service. Maintaining and restoring high quality wetlands may not only help control flooding, preserve water quality, and provide important habitat, it may help solve mosquito-related problems, as well.