Habitat for the Ribbed Mussel Geukensia Demissa (Dillwyn) Explained by Current Speeds Near and Stem Densities of Spartina Alterniflora and Phragmites Australis in Saw Mill Creek of the Hackensack Meadowlands

Marion McClary, Jr.

Fairleigh Dickinson University, 1000 River Road, Teaneck, NJ 07666, 201-692-2606

201-692-7349, mcclary@fdu.edu, http://inside.fdu.edu/pt/mcclary.html

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 similar current speeds or to similar stem densities, current speeds were measured with a flow probe and plant stems were marked with cable ties and counted in four replicate 1 m² quadrats near P. australis and in four replicate 1 m² quadrats near S. alterniflora in Saw Mill Creek of the Hackensack Meadowlands.  There was no significant difference in current speeds and stem densities around P. australis and S. alterniflora.  This could explain why there was no significant difference in the number of G. demissa around P. australis and S. alterniflora.  Future studies will investigate other sites and/or manipulate current speeds at the same site by manipulating stem densities to provide further evidence that current speed and stem density are important for habitat selection by G. demissa between S. alterniflora and P. australis. 

The work was funded by the New Jersey Sea Grant College Program (R/D-2003-3) and Fairleigh Dickinson University’s Grant-In-Aid of Research Program.