HEAVY-METALS IN SEADUCKS AND MUSSELS FROM MISTY-FJORDS-NATIONAL-MONUMENT IN SOUTHEAST ALASKA

Quartz Hill, in Misty Fjords National Monument near Ketchikan, Alaska, is the site of a proposed molybdenum-producing mine. To provide basel ine data for use in post-development comparisons, we analyzed tissues of Barrow's goldeneyes (Bucephala islandica), common mergansers (Mergu s merganser), and blue mussels (Mytilus edulis) for seven heavy metals that could potentially be released into the environment as a result o f mining operations. Specimens were collected in 1980, 1981, and 1982 from two fjords likely to be used for discharge of tailings from the p roposed mine and from two control fjords. Concentrations of arsenic, c admium, copper, chromium, molybdenum, lead, and zinc were measured in soft tissues of mussels and in kidney, liver, and muscle of birds. The highest mean concentrations of metals found in bird tissues were 55.7 ppm dry weight cadmium in kidneys and 154 ppm dry weight zinc in live rs of Barrow's goldeneyes. Concentrations of several metals in blue mu ssels differed among seasons and locations, but the most significant f inding in mussels was a maximum mean cadmium concentration of 9.6 ppm dry weight, a level higher than normally found in undisturbed areas. W ith the exception of 104 ppm dry weight cadmium in the kidney of one c ommon merganser and 12.7 ppm dry weight lead in the kidney of another, concentrations of other metals in seaduck and mussel tissues were low , consistent with what would be expected for a pre-development environ ment. Molybdenum was found in low concentrations (<10 ppm dry weight) in all avian kidney samples and most liver samples, but was not detect ed in blue mussels.