Florida’s unique geology results in a concentration of springs found nowhere else in the world. However, the biology and ecology of these springs and their associated cave systems is not well studied. Recently, the Cambrian Foundation was asked by Wekiwa Springs State Park to conduct a study investigating the role that microorganisms play in speleogenesis, or the development of caves. The Park staff also asked us to document the macrofauna (cave crayfish, iso/amphipods, etc.) that make up the cave community at Wekiwa Springs. In relatively nutrient-poor, low-light habitats like these caves, chemoautotrophic bacteria may fix carbon dioxide into organic matter using sulfur, iron or manganese. In addition to generating bacterial colonies, which may provide the base for the food webs in these caves, the geochemical reactions carried out by these microorganisms can influence both the formation and dissolution of minerals. For example, some caves contain large populations of microorganisms that produce sulfuric acid, which may promote cave formation and generate biomass to support other organisms.
With these overall objectives in mind, we began our first day of the 2005 phase of the Central Florida Karst Project by gathering at Wekiwa Springs State Park at 8:00 am. Andy Pitkin and Rhiannon Raggatt have come from the United Kingdom to join us in this two-week expedition. The dive team was also joined by microbial ecologist, Rima Franklin, Ph. D., and Jeff Chanat, a hydrologist, of Cocoa, FL. After an organizational meeting over breakfast, we got to work.
Our first task was to gather formation water from three wells on the Wekiwa Springs State Park property located upgradient from the main spring. The formation water will indicate the different concentration of minerals in groundwater located at various depths beneath the surface. In addition to gathering these samples and analyzing them for bacterial communities, we also examined nutrient levels and collected some biogeochemical data. Prior to completing our work at the wells, we installed three traps in order to monitor for cave crayfish and other troglobitic crustaceans in these waters.
Then, it was on to the Spring to gather more water samples and analyze differences in water chemistry (specifically dissolved oxygen, temperature, salinity, turbidity, redox potential, pH, nitrate, ammonia, iron, sulfide, etc.) from the surface to the end of the current survey line in the no-mount cave. Other tasks that had to be accomplished were to test the underwater-to-surface video camera and communications system and to place traps for troglobitic crustaceans in the cave and near its entrance. We collected 5 water samples from various sites in the no-mount cave and marked the location from which they were taken. We also started surveying the cave for production of a definitive map.