Exploring Prokaryotic and Viral Communities within Florida’s Freshwater Springs

Abstract

Florida’s freshwater springs serve as a crucial ecosystem for the state, having both ecological and economic importance. Springs occur where there is an opening where aquifers discharge groundwater. Florida’s springs are fed by the Floridan aquifer system (FAS), which underlies the entire state and extends into several neighboring states. The FAS provides potable water to over 10 million people. The constant flow of groundwater through the springs feeds major river systems and creates unique freshwater systems that support numerous plants and animals. The combination of natural beauty and charismatic fauna attract tourism and generate millions of dollars in revenue for the state. However, due to anthropogenic influences the health of the FAS and Florida’s springs have declined. Despite these challenges and the importance of the springs, little is known about the composition and dynamics of prokaryotic and viral communities living in the water. Prokaryotic and viral communities play a large role in maintaining the health of aquatic ecosystems. Microbial communities in the springs are a useful tool for monitoring ecosystem health; however, prior to this dissertation, there were no baseline data available. This dissertation explores both the spatial (Appendix A) and temporal (Appendix B) variation of prokaryotic and viral communities within the springs through the use of 16S ribosomal RNA gene sequencing and viral metagenomics. The spatial investigation generated snapshots of prokaryotic and viral communities within five first magnitude springs, demonstrating that these communities are unique to each site. The temporal investigation revealed spatial and temporal variability with a single spring system. These findings are supported when looking at the diversity and distribution of single-stranded DNA phage within these viral communities (Appendix C). This doctoral work provides the first descriptions of the prokaryotic and viral communities of Florida’s springs and a foundational understanding of the spatial and temporal dynamics of these communities for monitoring future changes