Dr. Lisa A Waidner

Excerpt - The project provided key baseline information about the shallow continental shelf environment in the northeastern Gulf of Mexico. This area is poorly studied compared to other continental shelves such as the South Atlantic Bight. Colonization of benthic invertebrates increased secondary production. This in turn supports higher trophic levels, particularly the commercially important reef fishes such as snapper, triggerfish and sheepshead. Results from this work represent one of the few studies of primary production, biogeochemical cycling, and the implications to fisheries production in the northeastern Gulf of Mexico. With the increasing deployment of artificial reefs in Florida, this provides key information for management of these habitats.

To determine baseline abundances of potentially dangerous species of bacteria, UWF CEDB researchers surveyed 44 locations in 7 major basins for the abundances of Vibrio vulnificus (V. vulnificus) and Vibrio parahaemolyticus (V. parahaemolyticus). We collected samples from 44 stations on 7 dates between 02/03/20 and 03/02/20. The average surface water temperature of all stations was 15.4 o C; and temperatures ranged from 12.3 – 22.2 o C. Surface water salinities ranged from 0.9 to 18.2 PSU. Surface water (n=44), sediment (n=43) and biofilm (n=14) samples were processed to assess abundances of Vibrio vulnificus and V. parahaemolyticus, employing a chromogenic agar assay. In surface waters, V. vulnificus was detected in 37 out of 44 samples, with maximum levels of 3,556 cells/mL. V. parahaemolyticus was only detected in 15 surface water samples, with a maximum concentration of 8,919 cells/mL. Sediments contained V. vulnificus in all but one sediment sample. V. vulnificus sediment concentrations ranged from 121 to 607,222 cells/mL. In contrast, V. parahaemolyticus were only detected in 33 of the 43 sediment samples, where concentrations ranged from 28 to 77,333 cells/mL. Biofilms, collected from oyster or barnacle shells or from invertebrate worms found in sediment samples, contained on average 7,735 and 1,490 cells/mL, of V. vulnificus and V. parahaemolyticus, respectively. In comparing biofilm abundances on different types of shells, there was not a statistical difference between oysters (n=5) and barnacles (n=7) for V. vulnificus (p=0.675) or V. parahaemolyticus (p=0.628). A partial analysis of these species' distribution with respect to water quality data was performed. Of note in our preliminary analyses is the statistically significant correlation between V. vulnificus abundances in sediments and the salinity observed in the water column at depth. Due to the University's response to COVID-19, sample laboratory processing, including total suspended solids (TSS), chlorophyll a, dissolved and total nutrient concentrations, was halted prematurely. Approximately 2/3 to ¾ of the laboratory-based water quality analyses are complete as of this date. However, all laboratory-based winter data and analyses of winter and summer data will be provided in the final report submitted on Nov 1, 2020.