Characterization of Bacteria Community and Evaluation of Anthropogenic and Natural Disturbances in Surface Waters Quality of Sabana River in the Luquillo Experimental Forest in Puerto Rico. Salgado-Herrera, Miriam. Universidad del Turabo (Puerto Rico), ProQuest Dissertations Publishing, 2017. 10285300.

Characterization of bacteria community and evaluation of anthropogenic and natural disturbances in surface waters quality of Sabana River in the Luquillo Experimental Forest in Puerto Rico. This doctoral dissertation research focused on the bacterial characterization, and evaluation of anthropogenic, and natural disturbances in the surface waters quality of the Sabana River in the Luquillo Experimental Forest in Puerto Rico. Monthly samples were taken at seven stations along the river during one year, and physicochemical factors such as temperature, pH, conductivity, DO and salinity were measured to explore their effect in the bacterial community. The effect of recreation was evaluated at El Puente, and at La Paila in the Sabana River, and at Puente Roto in the Mameyes River, from August 4 to September 8, 2012. Samples were collected up-river (before), on-site, and down-river (after) primary contact recreation activity. The number of bathers, and the temperature of the water were recorded. Also, four monthly sampling events were conducted under low flow conditions between May 2015 and August 2015, at two sites in the Sabana River impacted by non-point sources. Terminal restriction fragment length polymorphism (T-RFLP), pyrosequencing, and Colilert and Enterolert Test-System, were used for the bacterial community characterization. It was found that number of phylotypes of the bacterial community increases from upriver to downriver as anthropogenic disturbances proliferate along the river, and that bacteria are adapted or acclimated to in situ temperature, dissolved oxygen, conductivity, salinity and pH, therefore, show little variation in time and space. Pyrosequncing revealed that a total of 12 bacteria classes, 27 orders, 33 families, 82 genera and 186 species were found in the Sabana River. There is an increase in families and species through the three stations, with the largest amounts observed downriver at station # 7. Vogesella spp. was the most abundant specie at the three stations, with 59% at station # 1, 67% at station # 4, and 53% at station # 7. A significant positive and strong correlation was found between the amount of E. coli and the number of bathers at MPRS (R = 0.919; p-value = 0.027), which means that a high number of bathers coincides with a high concentration of E.coli.

Also, there is a significant positive and strong correlation between the concentration of Enterococci and the number of bathers at Pai.S (R is 0.908; p-value = 0.033). There were not significant differences between the bacterial community up-river, on site and down river of the two non-point sources.