Although recommendation 1 above would be the best way to determine the presence of 

 sediment pollution in Reach 1 5, the mussel filtering assay used in this project is an 

 economical alternative. The mussel filtering assay could provide useful information needed 

 to conserve native mussels. The mussel filtering assay, using infaunal mussel or clam 

 species, has shown promise as a valuable screening tool to assess the quality of sediments to 

 infaunal organisms (Sparks and Dillon 1993). The method needs to be calibrated with 

 established laboratory tests (e.g., midge growth assay). 



3. In situ, continuous biological monitoring devices, such as the Mossel Monitor or similar 

 devices (Waller et al. 1995) should be used to monitor water quality of the Upper Mississippi 

 River. 



The assays conducted during this study indicated that some sediments in Reach 15 of the 

 Upper Mississippi River are toxic to the benthic fauna. We recommend a continuous 

 monitoring program, such as the use of the Mossel Monitor, that measures biological 

 variables to detect pollution pulses traveling down the river through Reach 15. The use of 

 the Mossel Monitor would allow a manager to detect potential pollution problems and 

 identify likely sources of the problem before another disaster, like the mussel die-off of 19S1 

 through 1986, occurs again. 



