Water and sediment characteristics associated with avian botulism outbreaks in wetlands

Journal of Wildlife Management
By:  and 



Avian botulism kills thousands of waterbirds annually throughout North America, but management efforts to reduce its effects have been hindered because environmental conditions that promote outbreaks are poorly understood. We measured sediment and water variables in 32 pairs of wetlands with and without a current outbreak of avian botulism. Wetlands with botulism outbreaks had greater percent organic matter (POM) in the sediment (P = 0.088) and lower redox potential in the water (P = 0.096) than paired control wetlands. We also found that pH, redox potential, temperature, and salinity measured just above the sediment-water interface were associated (P ≤ 0.05) with the risk of botulism outbreaks in wetlands, but relations were complex, involving nonlinear and multivariate associations. Regression models indicated that the risk of botulism outbreaks increased when water pH was between 7.5 and 9.0, redox potential was negative, and water temperature was >20°C. Risk declined when redox potential increased (>100), water temperature decreased (10-15°C), pH was <7.5 or >9.0, or salinity was low (<2.0 ppt). Our predictive models could allow managers to assess potential effects of wetland management practices on the risk of botulism outbreaks and to develop and evaluate alternative management strategies to reduce losses from avian botulism.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Water and sediment characteristics associated with avian botulism outbreaks in wetlands
Series title Journal of Wildlife Management
DOI 10.2307/3802842
Volume 63
Issue 4
Year Published 1999
Language English
Publisher Wiley
Contributing office(s) National Wildlife Health Center
Description 12 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Wildlife Management
First page 1249
Last page 1260
Country United States
Online Only (Y/N) N
Additional Online Files (Y/N) N