GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 183-25
Presentation Time: 9:00 AM-6:30 PM


BERGMAN, Bailey, University of Iowa, Iowa City, IA 52242, CRAMER, Bradley D., Department of Earth and Environmental Sciences, University of Iowa, 115 Trowbridge Hall, Iowa City, IA 52242 and MILBRANDT, Eric, Marine Laboratory, Sanibel-Captiva Conservation Foundation, Sanibel, FL 33957

The purpose of this project is to explore the phytoplankton community composition differences along the Caloosahatchee River and Estuary and in the Gulf of Mexico over several dates before, during, and after discharge from Lake Okeechobee. We collected water samples from thirteen sites that include seven in the river/estuary itself and six in the nearshore environment adjacent to the estuary. Salinity, temperature, DO, depth, and chlorophyll-a measurements were also collected at each site. Discrete water samples were collected for analyses of nutrient concentrations. Phytoplankton composition and abundance were measured using Flowcam (10-100μm) and epifluorescence microscopy was used for picoplankton (<10 μm). We expect the dominant phytoplankton identified in Flowcam to change in response to changes in salinity and other environmental factors. Positive correlations between chlorophyll-a, total particles, and the dominant phytoplankton are expected in the samples. As a result of this study, we hope to see if there is a link between discharge from Lake Okeechobee and harmful algae blooms in the estuary and gulf. Understanding phytoplankton populations before, during, and after harmful algal blooms will help to improve prediction of the impacts of algal bloom events in the future.