Effects of a nonionic surfactant (c14-15AE-7) on fish survival, growth and reproduction in the laboratory and in outdoor stream mesocosms

Abstract

The effects of a nonionic surfactant (C{sub 14-15} AE-7) on survival and growth of juvenile bluegill sunfish and on survival and reproduction of fathead minnows were investigated in the laboratory and in outdoor stream mesocosms. In the laboratory, where the fish were exposed for 10 d, the 96-h LC50 values for bluegill sunfish and fathead minnows were 650 and 770 {micro}g/L, respectively. The no-observed-effect concentration (NOEC) for survival and swimming performance of bluegill sunfish and for survival of fathead minnows was 160 {micro}g/L. The lowest-observed-effect concentration (LOEC) for these toxic responses was 460 {micro}g/L. In the stream mesocosms, where the fish were exposed for 30 d, the NOEC for bluegill sunfish and growth was >330 {micro}g/L. The LOEC for fathead minnow survival was 330 {micro}g/L, and the NOEC was 280 {micro}g/L. Decreased egg laying by fathead minnows was noted in the streams at concentrations of 330 {micro}g/L or greater. Close correspondence between the results of laboratory tests and those obtained under field conditions in the mesocosms indicates that for this surfactant, it may not be necessary to apply ``safety factors`` to extrapolate results from the laboratory to the field.