RESULTS AND DISCUSSION 19 



Mussel Densities in Fleeted and Unfleeted Areas 19 



Effects of Boats on Mussel Corrals and Substrate 19 



Mussels Marked and Recaptured 2 2 



Problems With Small Sample Sizes 25 



Shell Damage in Mussels Collected for the First Time 28 



Shell Damage in Recaptured Mussels 3 2 



Mortality 32 



Growth 37 



SUMMARY 41 



LITERATURE CITED 43 



APPENDICES 45 



Appendix A. Scientific and Common Names and Species Codes 



for Live Mussels Taken 1984 from the Illinois River Study 



Site Near Naples, IL 47 



Appendix B. Quantitative Results of Transects Sampled 



in 1983 49 



Appendix C. Data for Mussels Captured and Marked in 



1984 55 



Appendix D. Data for Marked Mussels Recaptured in 1984... 87 



Appendix E. Report on Emergency Sampling to Verify 



Reports of a Mussel Die-Off in the Upper Mississippi 



River 91 



vi 



