DRENNAN, R.W.; MCCLARY, JR., M.; Fairleigh Dickinson University, Teaneck, NJ; Fairleigh Dickinson University, Teaneck, NJ: Low salinity does not control the distribution of barnacles in the tidal Hackensack River.

The barnacles, Balanus improvisus, are found and were once found in sites in the tidal Hackensack River of New Jersey. Previous transplantation studies conducted in the site, where they once lived, showed significant decrease in the percentage of living barnacles on transplanted rocks within three to nine days (from 70% to 14%). To determine if this decrease was due to salinity, eight rocks from the living site were separated into four pairs and placed into tanks filled with varying salinities (0.0, 4.0, 8.0, 12.0 ppt). After twelve days, living barnacles in 0.0 ppt water significantly decreased from 100% to 0.0% (P<0.001). This decline could be predicted by the number of cirral sweeps per minute which declined from 10.8% to 0.0% prior to death. All other barnacles in 4.0, 8.0, and 12.0 ppt water did not show any significant decrease for forty-three days. This is consistent with sweep rates that did not decline as well. The results of this study suggests that low salinity is not a factor in the distribution of living barnacles in the tidal Hackensack River. Future studies will determine the effects of salinity changes on Balanus improvisus.