Abstract |
Three snail species collected from western Oregon were exposed to metals - Juga plicifera and Lithoglyphus virens, which inhabit cool coastal streams, and Physa gyrina, which is found in Willamette Valley ponds. J. plicifera were exposed in flow-through laboratory tests to copper and nickel, L. virens were exposed to copper, and P. gyrina were exposed to nickel and zinc. J. plicifera has a 96-h LC50 (50% of the test group died) of 0.015 mg/L for copper and a no observed effect level (NOEL, mortality not significantly different from that in control groups) of 0.006 mg/L (30-d survival). J. plicifera had a 96-h LC50 for nickel of 0.237 mg/L and a NOEL of 0.124 mg/L. L. virens had a 96-h LC50 for copper of 0.008 mg/L and a NOEL of less than 0.008 mg/L. P. gyrina had a 96-h LC50 for nickel of 0.239 mg/L, a 96-h LC50 for zinc of 1.274 mg/L and a NOEL for zinc of 0.570 mg/L. |