HABITAT LINKAGES - THE EFFECT OF INTERTIDAL SALT-MARSHES AND ADJACENTSUBTIDAL HABITATS ON ABUNDANCE, MOVEMENT, AND GROWTH OF AN ESTUARINE FISH

In this study we used pinfish (Lagodon rhomboides) in field experiment s to examine linkages between intertidal saltmarsh and adjacent subtid al habitats. Pinfish are more than twice as abundant in intertidal mar shes adjacent to seagrass beds than in those adjacent to the unvegetat ed subtidal bottom. Movement of pinfish between the marsh edge and the adjacent subtidal habitat was greater for fish captured in areas with both intertidal and subtidal vegetation than in those with intertidal vegetation and adjacent unvegetated mudflats. This movement provides an important link between habitats, allowing transfer of marsh-derived secondary production to subtidal seagrass beds and vice versa. Pinfis h held in enclosures with both intertidal and subtidal vegetation were , on average, approximately 90% heavier than fish held in enclosures w ith intertidal vegetation and unvegetated subtidal bottom. Because sal tmarshes and seagrass beds contribute to the production of living mari ne resources, active measures are being taken to preserve and restore these habitats. The results from this study have direct application to decisions concerning site selection and optimal spatial proximity of saltmarsh and seagrass habitats in the planning of restoration and mit igation projects. To maximize secondary production and utilization of intertidal marshes, managers may opt to restore and/or preserve marshe s adjacent to subtidal seagrass beds.