Effects of acid mine drainage from an abandoned copper mine, Britannia Mines, Howe Sound, British Columbia, Canada, on transplanted blue mussels (Mytilus edulis)

Juvenile mussels (Mytilus edulis) were transplanted to Howe Sound, British Columbia, Canada, along an apparent pollution gradient of acid mine drainag e (AMD) from an abandoned copper (Cu) mine. Cages containing 75 mussels eac h were placed at a total of 15 stations and were exposed to concentrations of dissolved Cu in surface waters ranging from 5 to 1009 mug/1 for a period of 41 days. Mussels located at stations closer to the source of AMD at the mouth of Britannia Creek bioaccumulated higher concentrations of Cu and zi nc (Zn) in their tissues. Mussel growth was adversely affected by Cu tissue concentrations above 20 mug/g dry wt., while declines in survival and cond ition index occurred in mussels that bioaccumulated greater than 40 mug/g d ry wt. Cu. Tissue Zn concentrations (117-192 mug/g dry wt.) were likely not high enough to have a direct impact on mussel health. Reduced survival of transplanted mussels was supported by an absence of natural mussels in cont aminated areas. Phytoplankton was also severely reduced in areas contaminat ed by mine waters. Based on the weight of evidence, AMD from the Britannia mine had a deleterious impact on mussel survival in a zone extending at lea st 2.1 km to the north and 1.7 km to the south of Britannia Creek on the ea st shore of Howe Sound. (C) 2001 Elsevier Science Ltd. All rights reserved.