SHELL DAMAGE 



DOWNSTREAM 



GROUNDED PILING 



Note: Numbers at the top of bars indicate the total number of 

 live mussels collected from the plot in 1984. 



DOWNSTREAM = unfleeted plot, downstream control 



UPSTREAM = unfleeted plot, upstream control 



GROUNDED = fleeted plot, barges against shore 



PILING = fleeted plot, barges tied to pilings 



Figure 4. Shell damage rates for all live mussels collected in 

 1984 from fleeted and unfleeted plots in the Illinois 

 River at Naples. 



29 



