Boyd, Liberty

Bioturbators serve as ecosystem engineers, influencing community dynamics of the environments in which they are endemic. Currently, the bioturbator, Holothuria arenicola, a species of burrowing sea cucumbers, is listed as data deficient by the IUCN. These animals may affect the structure and function of seagrass beds, which are critical habitats for various species. To assess the ecological role of H. arenicola , I conducted field surveys, calculated mound, and analyzed mound nutrient levels. I gathered data through monitoring study plots, conducting Bran-Blanquette seagrass surveys (Fourqurean et al., 2001), capturing GoPro video, and collecting samples. Results indicate an insignificant difference between nutrient levels and the ambient environment. However, a positive correlation between seagrass density and active mounds correlation is suggestive of a non-nutrient related ecological relationship between burrowing sea cucumbers and seagrass density. Follow-up studies are needed to further asses the ecological role of H. arenicola on seagrass beds.

Sea turtles, like all marine vertebrates, can host considerable populations of epibionts, i.e., externally-attached symbiotic organisms on the skin and shell. These organisms can form facultative, obligate, and sometimes endemic commensal relationships with sea turtles, whose outer surface provides an insular, mobile substrate for their colonization and dispersal. Juvenile hawksbill turtles, Eretmochelys imbricata, living off Florida’s east coast can develop considerable epibiotic growth. I analyzed 236 photographs of 213 hawksbill turtles from SE Florida to document colonization patterns, relative abundance, and ecology of macroscopic commensals, including sea turtle barnacles (Chelonibia spp.), fire coral (Millepora spp.), and sponges (Porifera). I found that the epibionts increased significantly in overall abundance with turtle size. Hawksbill epibionts may reflect turtle movement and dispersal and can serve as a model for studying successional processes of epibiotic colonization.