propellers, probably pleasure boats which were beached at an 

 adjacent campsite. Corrals at the downstream control were 

 untouched. 



5. In general, shell damage rates and mortality rates were higher 

 in the fleeted plots than in the downstream control, but none of 

 the differences were significant (P < 0.055) with the small sample 

 size available. At the unfleeted upstream control plot, none of 

 the 41 mussels collected in June were damaged. In fall, after 

 summer use of the area by recreational boaters, 14 of 75 mussels 

 collected were damaged. 



6. Growth rates for most species were greater in the unfleeted 

 downstream control than in the fleeted areas. Differences between 

 plots were significant (P < 0.055) for the most frequently 

 recaptured species, Amblema plicata and Leptodea fragilis , but not 

 for any other species. 



7. Any effects of fleeting on mussels were probably at seasonally 

 minimal levels during our study. Fleeting activity reaches a low 

 during summer according to spokesmen for Naples Terminal Company. 

 Therefore, these trends must be considered inconclusive until we 

 obtain larger samples of marked mussels and allow more time for 

 damage, mortality, and growth to occur. 



42 



