Table 4. Probability (P) values for contingency tests comparing 

 shell damage and mortality of mussels from fleeted and 

 unfleeted plots in the Illinois River at Naples. 



Fisher's Exact Test 



2x2 



(pooled fleeted vs. 

 downstream control) 



Chi-Square 



2x4 

 (unpooled) 



Damage Mortality 



Damage Mortality n 



All species pooled 



0.074 



0.383 



167 



0.189 



172 



not applicable, no damaged shells recovered 



26 



