Water Resources Research Act Program

Details for Project ID 2013PR160B

The Total Microbial Community Structure and Enterococci Population Dynamics During a “recent fecal contamination event” in Seawater samples of Puerto Rico

Institute: Puerto Rico
Year Established: 2013 Start Date: 2013-03-01 End Date: 2014-02-28
Total Federal Funds: $10,713 Total Non-Federal Funds: $11,628

Principal Investigators: Luis Rios-Hernandez

Abstract: One of the biggest problems faced by societies around the globe is to guarantee and assess the quality of their waters; portable, recreational; to ensure the safety of their citizens. The EPA recommend that recreational marine waters that contain more than 35 CFU in 100 ml (geometric mean) or 104 CFU in a 100 ml in a single sample are not safe for swimmers. However, these guidelines were established by EPA studies conducted in states that are not representative of tropical environments. Even though, our previous and current research efforts minimize the human impact on our study site we feel that we need a more robust, culture independent and inclusive method of analysis assess the problem adequately. We hypothesize that the current method overestimates the contamination events and wrongly predicts a recent fecal contamination event in Puerto Rico’s waterways. Furthermore, we predict that the Enterococci population are re-introduced into the system by re-suspension from the sand or sediments from within the system and does not come directly from a human source outside the system as evidenced by the total microbial community structure. In this grant proposal we will attempt to study simultaneously the culturable population of Enterococci and the total microbial community structure in the same samples. Using this approach we will determine if the fluctuations in the culturable Enterococci population mirrors that of the total microbial population during a “recent contamination event”. This in depth analysis of the total microbial community could shed light to this complex task which is to describe a fecal contamination event based on microbial populations alone.