Abstract
Sediment toxicity was evaluated for one site upstream and three sites downstream of a diesel fuel spill that occurred in Fish Creek (OH and IN) in September 1993 using glochidia and juvenile unionid mussels. This fourth order tributary of the St. Joseph River has the only known remaining population of white cat’s paw pearly mussel, Epioblasma obliquata perobliqua, and populations of several other federal and state endangered mussels. The impact of the oil spill was of great concern because of the potential long term threat it poses to the survival of these mussels. Sediment samples collected two years after the spill contained low heavy metal concentrations, and detectable, but not quantifiable levels of organic components of diesel fuel. These levels coincided with their lack of toxicity to juvenile Villosa villosa and Lampsilis siliquoidea mussels after 9-day exposures. Fish Creek sediments may be toxic to L. siliquoidea glochidia.
