Variations of zooplankton community structure across a neritic-oceanic gradient off La Parguera, Puerto Rico

This study analyzes horizontal patterns of community composition and abundance of macrozooplankton across a neritic-oceanic gradient off La Parguera, Puerto Rico. Zooplankton samples were collected during three cruises; February 1995, August 1995 and May 1996 along three parallel transects (18°N, 67°00'W; 18°N, 67°03'W; 18°N, 67°06'W). Six stations positioned at 6, 10, 13, 16, 29 and 49 km from shore were occupied along each transect for a total of 18 stations. The horizontal distribution of total zooplankton and total holoplankton abundance was homogeneous across the entire gradient during the February and May cruises. A significant higher abundance of total zooplankton at neritic stations, as influenced by both holoplankton and meroplankton, was observed during the August cruise. Calanoid and cyclopoid copepods were the most abundant holoplankton taxa across the gradient. Foraminiferans, showed statistically significant increments of abundance at offshore stations during February and May. Ostracods also peaked offshore during the August and May cruises. Statistically significant differences of total meroplankton abundance were detected for all three cruises (ANOVA; p < 0.05). (Abstract shortened by UMI.)...