Accumulation and depuration of resin acids and fichtelite by the freshwater mussel Hyridella menziesi

Freshwater mussels incubated in the effluent of a kraft pulp and paper mill rapidly accumulated resin acids and fichtelite in their tissues, approaching a steady state in 7 d or less. Mean bioconcentration factors (BCFs) for individual resin acids varied from 110 to 330 L/kg dry wt. for 14-chlorodehydroabietic acid and abietic acid, respectively. The mean BCF for fichtelite was 4,900 L/kg dry wt., at least an order of magnitude greater than that of the resin acids. Resin acids were depurated rapidly from mussel tissue (biological half-lives of 3 d), whereas fichtelite concentrations declined more slowly (biological half-life 12 d). Depuration kinetics for these compounds appeared to be described by a first-order process. The possibility that the uptake process for fichtelite is zero order is explored.