Hepatic metallothionein production and resistance to heavy metals by rainbow trout (Salmo gairdneri)--II. Held in a series of contaminated lakes.

Rainbow trout held in net pens for 4 weeks in three locations contaminated by heavy metals developed elevated levels of hepatic metallothionein but no acclimation to a combination of zinc, copper and cadmium. Toxicity of the mixture of zinc, copper and cadmium in a ratio of 400:20:1 increased with temperature in the range of 6-21 degrees C. Hepatic metallothionein concentrations after 4 weeks of exposure in situ was correlated with the degree of contamination as measured by zinc concentrations (P less than 0.01).