•  
  •  
 

Georgia Journal of Science

Article Title

ASSESSMENT OF DIATOM MOVEMENT AND SPECIES COMPOSITION IN RELATION TO VARIOUS TIDE LEVELS ON ST. SIMONS ISLAND, GA

Abstract

As primary producers, the function of algae is determined by their shapes and sizes. The ability to travel up and down in mud and sand in coastal areas heavily affected the survival of algae within the aquatic habitats. This ability allows algae to live in diverse habitats with tidal cycles and escape periods of desiccation. Epipelic (growing on the mud surface) and epipsammic (growing attached to the sand particles) diatoms are the primary inhabitants of sand samples and are found within a thin horizontal and time dependent region at the sediment-water interface. While epipsammic algae might be exposed to desiccation at faster rate, motile epipelic diatoms can move to the surface during favorable conditions for maximum light exposure but then away from the surface to escape desiccation. Those movements are driven to maximize photosynthetic efficiency and increase the production of both ATP and storage material under favorable condition. The capacity to travel into the moist sand allows for some algae to survive longer periods of time than others that stay afloat on the sand surface. In this experiment, the movement distance of algae was documented from the northern region of St. Simons Island, GA using three different petri dishes of 0.5cm, 1.0cm, and 2.0cm. Live algal communities were assessed in every sample and live to dead diatom proportions in the communities were calculated. Cleaned diatoms were analyzed following standard protocols and used for species level identification. Community indices were compared through time and along the vertical gradient. Four algal groups were present including diatoms (Bacillariophyceae), Cryptophyta, Cyanobactera, and green algae (Chlorophyta). Thirteen genera were physiologically active in the surface community. Algal communities in the sampling site were dominated by epipelic representatives of the genus Nitzschia (Bacillariophycea). Diatom motility depended upon external temperature and time of sampling, other groups were less motile. The trophic system dependent on this community is at risk from increases in temperature and faster rates of post tidal desiccation.

This document is currently not available here.

Share

COinS