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EDUCATION
Ph.D. Oceanography (April 09 expected) University of Hawaii, Manoa Campus Honolulu, Hawaii
Dissertation Title (tentative) : Physical Forcing of Coral Reef Nutrient (CNPSiFe) Inventory Dynamics
Although the processes that enhance exchange within permeable coastal margins have been studied extensively in the past few years (Van Der Loeff 1981; Van Der Loeff et al. 1981; Moore 2000a; Moore 2000b; Huettel and Webster 2001; Precht and Huettel 2003; Webster 2003; Precht and Huettel 2004; Reimers et al. 2004; Wild et al. 2004a; Wild et al. 2004b), no study has documented nutrient dynamics in the water-column/sediment-porewater system over coral backreef environments during short sampling periods, as proposed in this study. Great gaps exist in our knowledge of short term nutrient inventories, and the sources and forces that shape their distribution within permeable margins where coral reef systems dominate. This study attempts to address such gaps and strives to elucidate the major mechanisms affecting variability in sediment interstitial water and water-column nutrient inventories. Although it is well understood that nutrient dynamics are site-specific, I hope to elucidate mechanisms that play important controlling roles in nutrient inventories at sites worldwide. Increasing our understanding of factors that affect the frequency and extent of solute exchange between high nutrient reservoirs (i.e., sediments, aquifer) and the water-column is of great ecological importance.
Committee: F.J. Sansone, K. C. Ruttenberg, M.A. McManus, C.M. Smith, and F. Mackenzie
See pdf of proposal
M.S. Soil and Water Science (2002) (Geography minor) University of Florida Gainesville, Florida
Thesis Title: Nitrogen Abatement Functional Evaluation of an Urban Wetland
Abstract Water quality exiting highly fractioned urban watersheds depends on the location and extent of detention basins or wetland systems within the area. Wetlands have been identified as having a great potential to help ameliorate non-point source nitrate exports to bays and estuaries. Nitrate export reductions help reduce eutrophication rates, thus helping preserve the trophic structure of estuarine systems. In this study, an urban bottomland hardwood hammock is evaluated for its potential functional role in abating nitrate loads from its surrounding landscape. Simple hydrologic and nutrient loading models were utilized to predict runoff water and total nitrogen (TN) loads to the wetland. Hydrologic model calibration and verification were performed on Carpenter Creek (CC), an adjacent USGS-gauged watershed, utilizing the SCS-CN method. Calibrated and verified model parameters for CC watershed were adapted to the Lower Jones Swamp (LJS) watershed by modifying the SCS curve number method empirical equations. Model output predicts the LJS watershed to generate 29.75 ± 10.15 cm of excess rainfall per year. All runoff is expected to enter the LJS. Nutrient loads to the LJS were predicted as 6855 kg of TN per year according to export coefficient per land cover calculations performed using Geographic Information Systems (GIS) analysis. Biogeochemical characterization of the top 5 cm of soil at our study site revealed a strong significant relationship between water extractable nitrate (NO3 ) and the denitrifying enzyme activity (DEA). Such relationship served as a basis for the premise that DEA could be utilized as an indicator of NO3 impact to a wetland. Covariance based PCA revealed that DEA explained most of the variability of this study’s log-transformed data. However, linear discriminant analysis revealed that TC, TN, and C:N ratios were the factors most strongly discriminating between impact levels. Strong significant correlations were found between moisture and extractable NO3, TN, and TC in upland sites, but stronger relationships were found in the wetlands. It is concluded that DEA serves as a good indicator of NO3 impact to wetland soils especially when flooded. However, DEA usefulness as an indicator of impact to the surface of more sandy upland soils is unclear. Furthermore, DEA and denitrifying potential of the soils in the LJS were studied and utilized as inputs to a geographical information system spatial analysis. Data manipulations utilizing inverse distance weighted interpolated surfaces revealed that the LJS could potentially denitrify greater than twice the amount of NO3-N being loaded to the system. Results from this study show the great potential of LJS to denitrify if conditions were optimal. This study further illustrates that nitrogen abatement properties are not homogeneous throughout the landscape of a disturbed urban wetland.
Committee: W. F. DeBusk, M. Binford, and K. R. Reddy. See pdf of thesis
B.S. Soil and Water Science (1998) University of Florida Gainesville, Florida
A.A. Biology, Honors Program (1996) Miami-Dade Community College Kendall, Florida
AWARDS RECEIVED · ESRI user conference student assistantship recipient- 2001 · Recipient of the PRA fellowship 2000-2001 – Organization of American States. · Recipient of the PRA fellowship 1999-2000 – Organization of American States. · Recipient of the F.B. Smith Scholarship award 1997 – Soil and Water Science, University of Florida. Outstanding Academic Achievement Award 1994-1995 – Miami Dade Community College.
LANGUAGES AND SKILLS · Fluent (read and write) in English and Spanish. Read and conversational in Portuguese. · Competent with Windows NT computer management, and proficient with ArcGIS,, ERDAS Imagine, and ENVI Geographic Information Systems/Remote Sensing software packages. · Hydrological Engineering Center (HEC-1) – Flood Hydrograph Package (US-ARMY Corps of Engineers) rainfall/runoff modeling experience. · Experienced with calibration, deployment, recovery, and data extraction from chemical (YSI - pH, conductivity, salinity, temperature, dissolved oxygen, chlorophyll a, and turbidity meter), and physical (waves and currents (Aquadopp), and light (LiCor)) multi-parameter data-loggers · AAUS Scientific Diver (Rescue diver, NITROX, and O2 Provider certified) · Department of Interior small boat operator certified · Trimble Pro XR Global Positioning System technology certified
Certifications OSHA Laboratory Safety Trained OSHA Hazardous Waste Generator Trained
TECHNICAL EXPERIENCE Automated Nutrient Analyzers (segmented flow) Sediment sampling (Upland, wetland, estuarine, coral reef) Physical oceanographic instrumentation (acoustic doppler velocimeters) Chemical oceanographic data-logging instrumentation (data sondes –YSI, Hydrolab, HOBO, OceanOptics) Ion Selective Electrodes Light sensing (LiCor) Web-page design and management
SHIP TIME RV SHARQ Express (~ 500 hours) – Benthic Biogeochemistry RV Walton Smith (~100 hours) – Gulf of Mexico Ammonium Tracing Coastal Research (various vessels < 25ft) >1200 hours
SCIENTIFIC DIVE-LOG Florida Keys (20 dives) Florida Springs (10 dives) Hawaiian Islands (Maui, Oahu - 80 dives) U.S. Virgin Islands (St. John - 40 dives)
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