Paper Type

Master's Thesis


College of Arts and Sciences

Degree Name

Master of Science in Biology (MS)



NACO controlled Corporate Body

University of North Florida. Department of Biology

First Advisor

Dr. Matthew Gilg

Second Advisor

Dr. Nicole Dix

Third Advisor

Dr. Eric Johnson

Department Chair

Dr. Cliff Ross

College Dean

Dr. George Rainbolt


If we want to understand how meroplankton utilize the water column and how their vertical distribution may influence horizontal advection, it is important to study their behavior in the various environments where they exist. In a well-mixed system with physical cues dampened, and no vertical layering, these organisms will have to depend on environmental cues such as light, tidal current, and tide cycle, as well as their own swimming ability to migrate vertically. Plankton and water samples were collected at three depths (near surface, midwater, near bottom) during the summers of 2013 and 2014 from sites within the main channel of the Intracoastal Waterway. Six taxonomic groups were collected including polychaetes, bivalves, gastropods, barnacles, tunicates, and crabs, and fell into one of three categories of vertical distribution. Certain preferences for vertical distribution, and habitat, of sessile invertebrates can increase, or provide refuge from, competition. To assess the potential competition for spatial resources between native and nonnative bivalves in the Guana Tolomato Matanzas estuary, settlement collectors with settlement plates at different depths were deployed for one month periods during the summers of 2013 and 2014 at two main channel sites and two feeder creek sites. Competition would likely be highest subtidally and within the main channel due to all species occurring in that habitat in higher numbers than the feeder creek.