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dc.contributor.advisorWhitmire, Stefanie
dc.contributor.authorChappell, Jessica
dc.description.abstractReservoirs of Puerto Rico are an important source of drinking water. The phytoplankton community is a large determinant of water quality, as some species are toxic. Thus, understanding the phytoplankton community structure is important to ensure clean reservoirs. Both field and mesocosm studies were completed using two reservoirs to identify the factors impacting the phytoplankton community structure. In the field study, reservoirs were sectioned into zones and sampling was conducted in “dry” and “wet” seasons to evaluate spatial and temporal differences in the phytoplankton and environmental parameters. Mesocosm experiments examined the direct impact of Corbicula fluminea on nutrients and the phytoplankton community. Results indicate parameters influencing the phytoplankton community structure differ depending on initial trophic status, as temperature and total phosphate played a major role in the mesotrophic system while specific conductance was the most important in the eutrophic system. Within each reservoir, a spatial gradient existed from the dam to riverine zone for several parameters, including secchi depth. However, temporal environmental patterns had the largest influence on the phytoplankton community structure. In the mesocosms, C. fluminea influenced phytoplankton dynamics but had no effect on nutrient concentrations; however, sediment was found to elevate total phosphate concentrations. Both studies show the reservoirs to be complex systems with several factors influencing their water quality.
dc.description.abstractLos embalses de Puerto Rico son fuentes importantes de agua potable. La comunidad del fitoplancton en los embalses es un factor que puede impactar la calidad del agua, ya que algunas especies son tóxicas. Por ende, necesitamos entender qué componentes influencian al fitoplancton para asegurar embalses saludables. Se hicieron estudios de campo y laboratorio, usando dos embalses, para identificar los factores que influyen en la estructura de la comunidad de fitoplancton. En el estudio de campo, los embalses estaban divididos en zonas y se tomaron muestras en épocas de “lluvia” y de “sequía” para buscar diferencias en tiempo y espacio en el fitoplancton y en los parámetros ambientales. Los experimentos de laboratorio sirvieron para examinar el impacto directo de Corbicula fluminea en nutrientes y en la comunidad de fitoplancton. Los resultados indican que los parámetros que influyen el fitoplancton dependen del estatus trófico inicial en el embalse. El fósforo total y temperatura tuvieron más influencia en el sistema mesotrófico, pero el conducto específico fue más importante en el sistema eutrófico. En cada embalse existe un gradiente espacial, pero los patrones ambientales tuvieron la mayor influencia en la estructura de la comunidad de fitoplancton. En los experimentos de laboratorio, C. fluminea tuvo un impacto en la dinámica del fitoplancton pero no en la concentración de nutrientes. El sedimento aumentó la concentración de fosfato total. Ambos estudios demuestran que los embalses son sistemas complicados con muchos factores que tienen un impacto en la calidad de agua.
dc.description.sponsorshipT-STAR 124 projecten_US
dc.subjectEnvironmental variablesen_US
dc.titleThe influence of environmental variables and an invasive freshwater bivalve on the Phytoplankton community of two tropical reservoirsen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2012 Jessica Chappellen_US
dc.contributor.committeeSantos-Flores, Carlos
dc.contributor.committeeSotomayor-Ramírez, David
dc.contributor.committeeMartínez-Rodríguez, Gustavo
dc.contributor.committeeO"Farrill-Nieves, Hipólito
dc.contributor.representativePadilla, Stefanie
dc.contributor.collegeCollege of Agricultural Sciencesen_US
dc.contributor.departmentDepartment of Crops and Agro-Environmental Sciencesen_US

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