Harmful algal blooms caused by the marine microalga Aureoumbra lagunensis have been associated with negative impacts on marine fauna, both vertebrate and invertebrate. Within the Indian River Lagoon (IRL) estuary system along Florida's east coast, blooms of A. lagunensis in excess of 1×106 cells mL-1 have occurred along with higher than average salinities (> 35 PSU) during times of peak reproduction and growth for the eastern oyster Crassostrea virginica. Field and laboratory studies were used to investigate the effects of A. lagunensis and high salinities on early life stages of eastern oysters, late pediveliger to early juvenile. Natural recruitment of C. virginica within Mosquito Lagoon (northern IRL) from 2013 to 2015 was negatively associated with blooms of A. lagunensis (>1×105 cells mL-1) and high salinities (>35 PSU), but recruitment of barnacle competitors was not. Larval settlement, tested using recirculating raceway flumes, was affected both by A. lagunensis and high salinities. Additionally, survival and growth rates of juvenile C. virginica were tested following one-week laboratory exposure to A. lagunensis and subsequent transplantation to the field for four weeks. Survival of juvenile oysters was negatively correlated with A. lagunensis and time (80% survival for A. lagunensis exposure and 90% survival when exposed to Isochrysis galbana control). Our results indicated negative impacts of Aureoumbra lagunensis on larval and juvenile eastern oysters during the term of the experiment. Oyster recruitment and growth continued during and following exposure to bloom concentrations of A. lagunensis, but at reduced rates.
Master of Science (M.S.)
College of Sciences
Length of Campus-only Access
Masters Thesis (Open Access)
Makris, Panagiota, "Effects of harmful algal blooms caused by Aureoumbra lagunensis (brown tide) on larval and juvenile life stages of the eastern oyster (Crassostrea virginica)" (2016). Electronic Theses and Dissertations. 5319.