Influences of sex, habitat, and seasonality on heavy-metal concentrations in the burrowing crab (Neohelice granulata) from a coastal lagoon in Argentina.

Cadmium, chromium, copper, and manganese concentrations were determined in hepatopancreas of both sexes as well as in eggs at different embryonic development stages of the burrowing crab Neohelice granulata (Brachyura, Varunidae) from Mar Chiquita Coastal Lagoon, a biosphere reserve from Argentina, during a period of 1 year, to assess the bioaccumulation of metals associated with sex and seasonality. Furthermore, metal levels in associated superficial sediment samples were also determined. Two different "cangrejales," one in a mudflat and another one in a salt marsh, were studied. The results showed high concentrations of copper within the hepatopancreas, which was considered a strong reflection of high exposure of N. granulata to this metal. Metal accumulation in hepatopancreas from both study sites and sexes did not present significant differences, as did seasonality. In this sense, both spring and summer metal levels in hepatopancreas were the greatest. Eggs did not present differences in metal accumulation, with the exception of manganese, between sites or between crabs at different embryonic stages. For this metal, eggs from female crabs inhabiting mudflats showed higher levels than those from inhabiting salt marshes. Moreover, eggs in the late embryonic stage also showed the highest manganese concentrations. Metal levels in sediments, however, were similar in both sites. These are the first results of metal level in biota and sediments in this particular environment. Such results could be used as a baseline for the monitoring of metal levels in future studies in Mar Chiquita Coastal Lagoon.