U.S. Environmental Protection Agency


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HERMANUTZ, R. 0., L. H. MUELLER, AND K. D. KEMPFERT. 1973. Captan toxicity to fathead minnows (Pimephales promelas), bluegills (Lepomis macrochirus), and brook trout (Salvelinus fontinalis). J. Fish. Res. Board Can. 30: 1811-1817.


U.S. government work.


The toxic effects of capt an on survival, growth, and reproduction of fathead minnows (Pimephales promelas) and on survival of bluegiIIs (Lepomis macrochirus) and brook trout (Salvelinus fontinalis) were determined in a flow-through system. In a 45-week exposure of fathead minnows, survival and growth were adversely affected at 39.5 μLg/Iiter. Adverse effects on spawning were suspected but not statisticaIly demonstrated at 39.5 and 16.5 μLg/Iiter. The maximum acceptable toxicant concentration (MATC), based on survival and growth, lies between 39.5 and 16.5 μLg/liter. The lethal threshold concentration (LTC) derived from acute exposures was 64 μLg/liter, resulting in an application factor (MATC/LTC) between 0.26 and 0.62. LTC values for the bluegill and brook trout were 72 and 29 μLg/liter, respectively. The estimated MATC is between 44.6 and 18.7 μLg/liter for the bluegill and between 18.0 and 7.5 μLg/liter for the brook trout.

The half-life of captan in Lake Superior water with a pH of 7.6 is about 7 hr at 12 C and about 1 hr at 25 C. Breakdown products from an initial 550 μLg/Iiter of captan were not lethal to 3-month-old fathead minnows.