Date of Award
Bachelor of Science (BS)
College of Science
Numerous studies have focused on the complex relationship between phytoplankton and zooplankton in estuarine environments, but few have scrutinized the effects of this connection on organisms in higher trophic levels. This study examined chlorophyll a concentrations and zooplankton densities in North Inlet, South Carolina, a site where a stable chlorophyll a maximum has been documented to exist at low tide, to determine if they influenced the distribution of resident bottlenose dolphins (Tursiops truncatus). We hypothesized that patterns of estuarine circulation in the salt marsh serve to concentrate phytoplankton and zooplankton predictably in time and space, and that these patterns influence the distribution of organisms at all trophic levels, including apex predators, in the marsh. During surveys in September through November of 2008, water samples for chlorophyll and tows for zooplankton were taken at two-hour intervals throughout the tidal cycle along a gradient of five sites centered around the historic chlorophyll maximum. Correlations between zooplankton densities and phytoplankton concentration were unexpectedly low and the chlorophyll a maxima were more spatially unpredictable than in previous studies. However, the distribution of dolphin sightings, both present and from 1999 through 2003, suggests that chlorophyll a maxima influence dolphin distribution in North Inlet, particularly during the warmer months out of the year.
Thornton, Steven W., "Effects of a Spatially and Temporally Predictable Chlorophyll Maximum on Bottlenose Dolphin Distribution in a South Carolina Estuary" (2009). Honors Theses. 154.