ENVIRONMENTAL-EFFECTS OF A HARD CLAM (MERCENARIA-MERCENARIA) AQUACULTURE SITE IN THE INDIAN RIVER LAGOON, FLORIDA

The impact of the growout of cultured hard clams was evaluated at a co mmercial mariculture site in the Indian River Lagoon, Florida. Selecte d biological, chemical and physical factors were compared between a ha rd clam growout facility and two nearby reference locations. Measureme nts of water column nutrients, chlorophyll and dissolved oxygen concen trations gave no indication of differences which could be associated w ith the presence of the clam farm. Alteration of sediments towards a d ecreased mean sediment grain size associated with an increase in silt/ clay sized particles, as well as an increase in organic content, were observed within 1 m of clam growout bags. Sediment changes did not res ult in significant changes in benthic dwelling organisms. Differences in mobile macrofauna were minimal, and most differences appear to be a ssociated with variation in seagrass coverage.