DEVELOPMENT OF A FIELD BIOASSAY WITH JUVENILE MUSSELS

Two embayment sites in Kentucky Lake, an impoundment of the Tennessee River, have low species diversify of mussels. A field bioassay with B- wk-old laboratory-cultured juvenile mussels (Utterbackia imbecillis Sa y) was developed and used to compare these sites with a reference site . Mussels exposed to sediment at the test sites exhibited higher mean mortality than those exposed only to overlying water. Results showed s ignificant mortality at both low-diversity sites: 97% mortality at a s ite where mussels were absent, and 51% in a mussel bed with limited sp ecies diversity. Mortality of sediment-exposed juvenile mussels at a r eference site with diverse species was only 21%. Based upon the result s of this study, field assays with juvenile mussels can be used to ass ess stress in aquatic ecosystems.