Heavy Metal Stress and Increased Susceptibility of Steelhead Trout ( ) to Infection
SourceSteelhead trout exposed to zinc concentrations as high 98 ppb did not demonstrate increased susceptibility to Yersinia ruckeri infection. Exposure to cadmium at 0.9 ppb did enhance susceptibility to infection; however, the exposure level was near the LC50 for cadmium against steelhead trout.
Exposure of steelhead trout to copper concentrations as low as 2.0 ppb, which is considerably below the LC50 for steelhead trout, increased their susceptibility to Y. ruckeri infection. The time of exposure to the 10 ppb copper showed that maximum infection occurred after 48 h of exposure; however, a 12-h exposure could increase infection in the host fish.
Results of this research show that the study of specific stress in fish caused by exposure to certain toxicants may be best studied by determining their susceptibility to a pathogen.