Information dissemination in the water resources field

Abstract

A study of mercury accumulation in trout taken from the trout parks and streams of southern Missouri is presented. Mercury in trout is determined by digestion in nitric acid, sulfurid acid, and potassium permanganate, followed by reduction and aeration for measurement by flameless atomic absorpotion. The mercury accumulation in trout collected and analyzed in this project ranged from 0.1 to 0.3 ppm mercury (ug mercury/g of tissue). The mercury levels were relatively constant and showed no variation or higher level accumulation with increased size. The results of the analysis on the liver and flesh of the same trout showed that the levels in the liver were slightly higher than the levels in the flesh. Previous analysis of trout collected in the mid to late 1950's from the Little Piney River indicated mercury accumulations of approximately 3 ppm. Over the past 25 years, there has been a substantial decrease in mercury found in trout of southern Missouri as a result of cleaner streams.