Environmental and climatic factors associated with epizootic ulcerative syndrome (EUS) in fish from the Zambezi floodplains, Zambia.

Abstract

This study was conducted to determine environmental and climatic factors associated with Epizootic Ulcerative Syndrome (EUS) in fish in the Zambezi floodplains. EUS is a fish disease that causes economic loses to the fishing industry. Streambed colour in affected water was rusty-, reddish- or yellowish- brown and pH 4.5-6.0 while pH of non affected water was 7.2. The rusty-brown precipitate on fish gills was positive for Prussian blue iron stain. Therefore, predisposing factors for EUS in the Zambezi floodplains were the acidification of ground water during drought years and eventual contamination of surface water during the floods of 2006/2007.