ABSTRACT 



In June 1984, we collected 735 live mussels from the Illinois 

 River in the vicinity of the Naples Terminal Company, Naples, IL, 

 between river miles 62 and 67. We engraved an identification 

 number on both valves, determined height and length, and noted 

 any damage to the shells. We replaced marked mussels on the 

 bottom in or near 1.5-m aluminum corrals. Mussel corrals were 

 grouped in two experimental (barge fleeting) plots and two 

 control (no barges) plots. In October 1984, we resampled the 

 plots. In one of the fleeted plots, barges are tied to pilings, 

 and corrals in that plot were bowed and pushed into the 

 substrate. In the other fleeted plot, barges are grounded, and 

 the corrals had been destroyed. Corrals in the upstream control 

 plot had been struck by propellers of small pleasure boats, while 

 the downstream control corrals were unscathed. We recaptured 3 

 of 16 dead shells and 175 of 735 live mussels marked in June. In 

 general, shell damage rates and mortality rates were higher in 

 the fleeted plots than in the downstream control. Growth rates 

 for most species were greater in the unfleeted downstream control 

 than in the fleeted areas, and differences between plots were 

 significant (P < 0.055) for Amblema plicata (the three-ridge) and 

 Leptodea fragilis (the fragile paper shell) . However, there were 

 no other statistically significant differences, probably because 

 of the small numbers of recaptures. Therefore, the trends for 

 responses other than growth in two species must be considered 

 inconclusive until we obtain larger samples of marked mussels and 

 allow more time for damage, mortality, and growth to occur. 



Sparks, Richard E., and K. Douglas Blodgett 



EFFECTS OF FLEETING ON MUSSELS 



Interim Report to the Illinois Department of Conservation and the 



National Marine Fisheries Service, August 1985 



KEYWORDS — mussels/ Unionidae/ navigation/ navigation effects/ 

 fleeting/ fleeting areas/ barges/ towboats/ terminals 



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