COOPERATIVE GEOLOGICAL AND BIOLOGICAL FIELD STUDY OF PIGEON CREEK LAGOON, SAN SALVADOR ISLAND, BAHAMAS

A survey of the Holocene Pigeon Creek tidal lagoon on San Salvador Island was conducted by integrated teams of undergraduate geology and biology students and faculty advisors as part of a cross-listed course in geology and biology: The Natural History of Tropical Marine Systems. In the classroom, students were "cross-trained" in basic concepts of carbonate sedimentology and tropical marine ecology. Long-term goals were to: (1) gain an understanding of tropical marine ecosystems, (2) develop and conduct interdisciplinary research, and (3) capitalize on individual disciplinary strengths within integrated teams. Immediate goals were to: (1) record the spatial distribution and density of marine grasses, callianassid burrows, calcareous algae, and other invertebrates, (2) characterize the carbonate sediment of the lagoon, and (3) gather additional physical and biological data to serve as a baseline for future, monitoring studies.

Using 0.25 m2 PVC grids, and recording data on underwater tablets, students identified and recorded the occurrence of plant and sessile invertebrates along transect lines across the lagoon. Since most shallow water tropical fishes are territorial, students were able to generate a general species inventory for the lagoon. Sedimentological analysis utilized both surface grab samples from the coarser tidal delta and channel, and 1 m long cores, extracted along transects across the main lagoon. Sieved sediment samples were examined in order to determine the nature and origin of calcareous sediment. Physical data were collected using Hondex© digital depth sounders, Brix© salinity refractometers, and Enviro-Safe© laboratory thermometers.

Initially, not every student sees the value of cross-discipline training, but by the end of the field project all of the students gained an appreciation for each other's disciplines. Most students, without prompting from faculty, came to realize that science disciplines are not mutually exclusive and do not operate independently of each other. More importantly, students gained valuable team experience and a background for conducting a cooperative research program with publishable results. Elements of this project have already been published in the American Journal of Undergraduate Research.