Copper contamination and cadmium, silver, and zinc concentrations in the digestive glands of American lobster (Homarus americanus) from the inner Bay of Fundy, Atlantic Canada

The Bay of Fundy, Atlantic Canada is the habitat for important commercial stocks of the American lobster, Homarus americanus, as well as a number of other species. In order to protect these valued resources, and the consumers, information regarding the contaminants and the associated environment is essential. The Bay of Fundy is one of the better studied tidal estuaries in the world in the field of sedimentology (Amos 1984), various biological components (Gordon and Dadswell 1984), and since 1976, the chemistry of the water column and sediments, including inorganic nutrients, plant pigments, organic carbon and nitrogen, and inorganic elements, has been examined (Keizer et al. 1984). With the exception of work conducted in Saint John, New Brunswick (Dadswell 1979), however, data for metal contaminants in the marine biota are largely unavailable for the Inner Bay of Fundy. It has been shown that lobsters can accumulate high concentrations of heavy metals (Cu, Cd, Zn and Ag) in the digestive gland and thus are good indicators for monitoring changes in environmental metal levels (Chou et al. 1987; Chou and Uthe 1978; Conn Dept. Env. Prot. 1987; NOAA 1996). In addition, metal levels in lobsters can exceed levels acceptable for human consumption (NOAA 1994); for example unsafe Cd concentrations, as high as 223 mu g/g wet weight, were reported in lobsters from Belledune, New Brunswick at the site of a lead smelter plant (Uthe and Chou 1985). In a prior study of baseline metal levels in lobsters from the eastern and southern shores and the Annapolis Basin of Nova Scotia, unusually high levels of Cu (70.5 mu g/g wet weight) were found in Annapolis Basin lobsters, compared to 10.4 mu g/g wet weight in animals from Pubnico, the control site (Chou et al. 1998). Although Cu is a micronutrient in fish, it can also be toxic at elevated levels (Van Aggelen and Moore 1986). It is a required element in human nutrition, however, excessive consumption can negatively affect people, in particular in those suffering from Wilson's disease (CDA-UK 1992). Accordingly, this research was undertaken to compile baseline data to assess the distribution of metals in Bay of Fundy lobsters. It is part of an overall program to map the concentrations of heavy metals in the digestive glands of lobsters captured from around Nova Scotia to gauge the well-being of lobster stocks and to use them as a general index of marine environmental quality as required by the Department of Fisheries and Oceans Canada.