Using Chaetognath Species as Indicators of Water Masses in the Florida Current, Broward County, Florida, USA

Chaetognaths are one of the most abundant zooplankton found in marine waters. Research has shown that due to the temperature and salinity preferences of chaetognath species, chaetognaths can be used as indicators of water masses. In 2007 zooplankton were collected at three sites and two depths over 5 non-consecutive months along the continental shelf and slope off Fort Lauderdale, Florida. Chaetognaths were identified to species, enumerated and the densities were compared to temperature and salinity data acquired during sampling events. Flaccisagitta enflata, Sagitta serratodentata , and Krohnitta pacifica were the most dominate species found during the with a densities (ind./L) of 41967.77, 7662.00, 4208.95 respectively. Each collection period thermo - and haloclines were observed within the CTD data. Ferosagitta hispida, Mesosagitta minima, and Sagitta bipuctata demonstrated a significant correlation to temperature and S. bipunctata and F. hispida showed a significant correlation to salinity. Shipboard ADCP data was collected during each collection and indicated variability in the location and magnitude of the Florida Current front. This may explain the variability of temperature and salinity and the distribution of nearshore and offshore species.