The
Effects that Surrounding Hard Structures have on Biodiversity and
Abundance Found in Turtlegrass (Thalassium
testudinum) Patches

Hamm,
T., Le.S, and Miller, P.

Abstract

For
our project, we decided to see how structures may influence the
communities in the surrounding turtlegrass
(Thalassia testudinum)
meadows.
This was done by comparing two turtlegrass patches; one relativately
close to significant structures, and one approximately 50 meters
away. Structures include, mangroves (Rhizophora mangle), and dead
coral reefs. Over the course of five days, five samples of turtle
grass was taken daily at each site. We also sampled the populations
of epibenthic invertebrates and fish using five meter transects,
twenty-five meters per site per day. The seagrass samples were
analyzed to determine the number of leaves, number of bite marks, and
epiphytic algal coverage per square meter and meter of seagrass
surface area. The density of bite marks and epiphytic algal coverage
was used as a proxy for (determining a level) of herbivory at each
site. Average abundances of individual species were compared between
the two sites, as well as the Shannon-Wiener index, the Simpson
index, and a dominance curve, in order to compare the diversity and
abundance of species at each site.

Peter diving to conduct a bottom survey.