Physiological and behavioral responses of stonefly nymphs to enhanced limestone treatment of acid mine drainage

A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD to enhance l imestone neutralization of AMD. We conducted laboratory studies to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Ple coptera) exposed to effluents produced by the treatment system. Survival, s odium balance, drift, and feeding responses by P. proteus to treated and un treated AMD were examined. P. proteus nymphs exhibited significant losses o f whole body sodium in exposures to untreated AMD. Nymphs exposed to treate d effluents experienced no loss of whole-body sodium. Nymphs exposed to unt reated AMD showed elevated drift rates and depressed feeding rates relative to those of nymphs exposed to treated AMD. and to AMD-free controls. No si gnificant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The tr eatment system, with and without CO2 pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physi ological function. (C) 2001 Elsevier Science Ltd. All rights reserved.