student research

Habitat refuges are important ecological spatial components that can alter the survivability of organisms by providing relief from ecological pressure, such as predation, disease prevalence, and environmental stressors. If a habitat is considered to be a disease refuge this means that something unique occurred that reduced disease prevalence and intensity. Two different types of oyster habitats (mangroves and reefs) and micro habitats (low and high prop roots and reefs) were studied to determine whether differences in the internal environmental of oysters varied between habitats. Analysis of internal oyster surface and body temperatures along with oyster body salinity showed that differences in microhabitats affected body temperature and salinity. Oysters in both mangrove habitats exhibited lower body salinity and lower temperature than those on oyster reefs. We also analyzed disease prevalence and intensity of Perkinsas marinas among the different habitats and micro habitats by collecting oysters that were >1 year old. Results indicated variability of disease prevalence and intensity among the different habitats, with lowered disease prevalence and intensity seen on mangrove prop roots. These results indicate that mangrove prop roots may provide a habitat refuge for oysters from the parasite Perkinsas marinas.

This paper presents the design process of an underwater housing and mount for the LytroTM light field rendering (LFR) camera system. One interesting property of the LFR camera is the Synthetic Aperture Imaging (SAl). The objective of this project is to use the SAl property of the LFR camera to develop the image acquisition apparatus that will be the foundation of an aquaculture breeding tanks fish larvae population estimation system. The design, fabrication and assembly of the apparatus are illustrated in the paper. Results from the initial evaluation tests of the apparatus using a staircase calibration target in three difference scenarios: in the air, in fresh water and in turbid salt water are analyzed. The results from the in air tests fully demonstrated the SAl propetiy of the LFR camera: to take pictures of resolution targets at various depths and
individual focus on them during post processing. Overall, promising test results were obtained from the fresh water and salt water tests, but further improvement of the system will be required to achieve the optimal results. This paper outlines the ground work for this project and the very first test results gathered with this system and will provide a solid base for futiher research and testing to build on.

Algal symbionts, commonly called zooxanthellae, living in within coral tissues provide
energy to hermatypic corals through photosynthesis. Zooxanthellae density, as well as
photosynthetic pigment concentration, can be used as an indicator of coral health. This study compared zooxanthellae densities and concentrations of chlorophyll a and c between four sites and two species of coral, Montastraea cavemosa and Diploria clivosa, found at the St. Lucie Reef to establish baseline levels for comparison to future levels. No significant differences were found among sites despite increasing depth farther from the inlet, suggesting reduced light penetration closer to the inlet. Significant differences were found for zooxanthellae densities and chlorophyll concentrations per zooxanthellae cell between coral species. However, there was no significant difference for chlorophyll concentrations per unit area of coral tissue between species. This suggests that all site locations experience similar conditions despite differences in depth. It also suggests potentially different types of zooxanthellae, which is being addressed by ongoing research.

In 2009, Link Summer Intern, Lauren Nys, started a program surveying manatees in the Harbor Branch channel. Five years later, the program has accrued an abundance of data with the daily help of numerous volunteers. This project compiles and analyzes the data to answer questions about the abundance and behaviors of the resident population of manatees in the Harbor Branch channel. The manatees were found to have a general yearly abundance trend having high numbers in the winter and preferring to aggregate in the West Basin. There is no obvious effect of the 2010 cold stun, however, further research involving photo-identification analysis needs to be completed. The main behaviors exhibited in the challllel involve resting, staying warm, and mating, signifying that the channel is an important habitat for manatees. This project will continue as part of the researcher's undergraduate thesis.

The Lander is an underwater research platfonn that is capable of carrying a variety of scientific instruments. The largest instrumental package that can be attached consists of a continuous wave laser transmitter, a pulse modulated laser transmitter, an Altimeter, an AC-9 optical sensor, a conductivity temperature and depth sensor, an LISST optical sensor, a GPS beacon and an acoustic modem. The continuous wave laser transmitter housing consists of a variable power single mode low noise OEM laser and a galvanometer scanner and is mounted on a pan and tilt unit. The rest of the instruments are attached to the frame of the Lander using various fixtures. There is also an acoustic release attached to the back of the frame which is to be used for retrieval purposes.