JOURNAL OF PLANKTON RESEARCH j VOLUME 32 j NUMBER 1 j PAGES 75–91 j 2010 Vertical distribution and diel patterns of zooplankton abundance and biomass at Conch Reef, Florida Keys (USA) KARLA B. HEIDELBERG1*, KERI L. O’NEIL2, JOHN C. BYTHELL3 AND KENNETH P. SEBENS4 1 DEPARTMENT OF BIOLOGICAL SCIENCES AND WRIGLEY INSTITUTE OF MARINE SCIENCE, UNIVERSITY OF SOUTHERN CALIFORNIA, LOS ANGELES, CA 90089, 2 3 USA, NATIONAL AQUARIUM IN BALTIMORE, 501 E. PRATT STREET, BALTIMORE, MD 21202, USA, SCHOOL OF BIOLOGY, NEWCASTLE UNIVERSITY, NEWCASTLE 4 UPON TYNE NE17RU, UK AND UNIVERSITY OF WASHINGTON, FRIDAY HARBOR LABORATORIES, 620 UNIVERSITY ROAD, FRIDAY HARBOR, WA 98250, USA *CORRESPONDING AUTHOR:
[email protected] Received June 24, 2009; accepted in principle September 28, 2009; accepted for publication September 30, 2009 Corresponding editor: Mark J. Gibbons Zooplankton play an important role in the trophic dynamics of coral reef ecosys- tems. Detailed vertical and temporal distribution and biomass of zooplankton were evaluated at four heights off the bottom and at six times throughout the diel cycle over a coral reef in the Florida Keys (USA). Zooplankton abundance aver- aged 4396 + 1949 SD individuals m23, but temporal and spatial distributions varied for individual zooplankton taxa by time of day and by height off the bottom. Copepods comprised 93–96% of the abundance in the samples. Taxon- based zooplankton CHN values paired with abundance data were used to estimate biomass. Average daily biomass ranged from 3.1 to 21.4 mg C m23 and differed by both height off the bottom and by time of day. While copepods were the numerically dominant organisms, their contribution to biomass was only 35% of the total zooplankton biomass.