Analysis of Seasonal Changes in Community Composition of Seagrass Epiphytes in Aransas Pass, Texas

Generally, the type, and number of epiphytes found on seagrasses varies based on the time of year and the nutrient load of water, including man-made nutrient sources such as wastewater effluent. This study will examine the changes in community composition of epiphytes found on T. testudinum as a function of porewater nutrients and other environmental factors. Epiphytes will be removed from seagrasses collected seasonally from the ICW RV Park in Aransas Pass, Texas. Sites within the study area were chosen based on their proximity to the release point of wastewater effluent from the Aransas Pass Wastewater Treatment Plant. Comparative analysis of fluorescence was done using four wavelengths: 415nm and 680nm were used to determine the amount of green pigments in the sample associated with green algae and 530nm and 576nm were used to determine the amount of red pigments in the sample associated with red algae. These measurements were then compared to determine the ratio of red to green pigments within the samples. Samples will also be run through a full pigment analysis. This will be done using acetone to extract the color from the samples and then analyzing the solution produced in a spectrophotometer. Preliminary results show that both summer and winter samples had higher levels of red algae than green algae when comparing fluorescence analysis. However, individual sites differ, with some showing decreases in red pigment domination and others showing increases from summer to winter. However, further analysis and sampling needs to be done before any final patterns can be suggested. This project will allow for a better picture of the seasonal changes in epiphyte composition on T. testudinum and provide some comparisons between sites with differing nutrient inputs, especially those influenced by wastewater effluent.