Effects of CaCl2 and CaBr2 on the fecundity of Planorbarius corneus L.

Saturated water solutions of calcium chloride (481.3 g CaCl2 / L) and calci um bromide (1065.9 g CaBr2 / L) and their mixtures, commercially prepared a s "high density brines", are regularly used during special operations in ex ploration and production of natural gas and crude oil. After operations, al l workover fluids are left in the environment as waste. In the present stud y, the effects of several sublethal concentrations of these solutions (CaCl 2 1202 ppm, 2403 ppm and 4796 ppm, CaBr2 1065 ppm, 2663 ppm and 5325 ppm, 1 :1 volume mixture 773.9 ppm, 1931 ppm, 3855 ppm and 5779 ppm) on the fecund ity of the freshwater snail Planorbarius corneus L. were laboratory tested. During the six week exposure a considerably reduced fecundity was found. T he tested CaCl2. solution concentrations reduced fecundity by 53.9-84.4 %, CaBr2 by 72.3-90.8 % and the mixture by 72.5-94.0 % compared with the contr ol groups. (C) 1999 Elsevier Science Ltd. All rights reserved.