Habitat differences between Phragmites australis and Spartina alterniflora are slight for the ribbed mussel Geukensia demissa (Dillwyn) in Saw Mill Creek of New Jersey’s Hackensack Meadowlands

MCCLARY, M.*; Fairleigh Dickinson University: Habitat differences between Phragmites australis and Spartina alterniflora are slight for the ribbed mussel Geukensia demissa (Dillwyn) in Saw Mill Creek of New Jersey’s Hackensack Meadowlands.

Previous studies in Saw Mill Creek of the Hackensack Meadowlands of New Jersey showed that the invasive reed, Phragmites australis, had as many, if not more, Geukensia demissa around them as the cord grass, Spartina alterniflora. To determine if this was due to differences in recruitment that was induced by speed of the current, predation and or stem density, individual mussels were marked using surveyor flags, current speed was measured with a flow probe, some mussels were caged when others were not, and plant stems were marked with cable ties in four replicate 1 m2 quadrants near P. australis and four replicate 1 m2 qudrants near S. alterniflora in Saw Mill Creek of the Hackensack Meadowlands. There was no significant difference in recruitment, current speed and stem density around P. australis and S. alterniflora. The significant decline of caged G. demissa near S. alterniflora was due to significantly more G. demissa near P. australis than near S. alterniflora. Future studies will investigate other sites and determine the reason for the decline of caged mussels. Funded by the N.J. Sea Grant College Program (R/D-2003-3).

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