Current Search: Sediment (x)
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Title
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Sediment layer tracking using neural networks.
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Creator
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Freyermuth, Vincent Nicolas., Florida Atlantic University, Schock, Steven G.
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Abstract/Description
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The detection of sediment layer interfaces in normal incidence acoustic reflection data is a requirement for automatic classification and geologic mapping of subsurface layers. The detection is difficult because of the constructive and destructive interference caused by the impedance changes in the sediment column and high scattering noise levels. The purpose of this work is to implement a procedure using neural networks that automatically detects the sediment layers from the envelope of...
Show moreThe detection of sediment layer interfaces in normal incidence acoustic reflection data is a requirement for automatic classification and geologic mapping of subsurface layers. The detection is difficult because of the constructive and destructive interference caused by the impedance changes in the sediment column and high scattering noise levels. The purpose of this work is to implement a procedure using neural networks that automatically detects the sediment layers from the envelope of acoustic reflections. The data was collected using a sub-bottom profiler that transmits a 2 to 10 kHz FM pulse. The detection procedure is a three step method: a first neural network removes most of the reflections due to random scatterers, a second neural network tracks the layers and a third algorithm recognizes the segments of detected layers corresponding to the same sediment interface Applied on different sub-bottom images, the procedure detects more than 80% of the layers correctly.
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Date Issued
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1998
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PURL
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http://purl.flvc.org/fcla/dt/15561
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Subject Headings
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Neural networks (Computer science), Marine sediments--Acoustic properties
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Format
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Document (PDF)
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Title
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The laboratory measurement of soluble phosphorus diffusion coefficients in kaolinite and bentonite clay sediments.
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Creator
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Donovan, William Cullen., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D.
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Abstract/Description
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The specific effects of sediment resuspension on the rate and amount of phosphorus diffusion by commercially available kaolinite and bentonite soils were examined in a laboratory setting by amending the soils with phosphorus fertilizer (46% P2O5), reacting them in a plexiglass container (by removing a partition) and allowing the soils to mix with the overlying water column as they spread along the container bottom. The concentration of total phosphorus was measured at 1, 3, 6, 12, 24 and 36...
Show moreThe specific effects of sediment resuspension on the rate and amount of phosphorus diffusion by commercially available kaolinite and bentonite soils were examined in a laboratory setting by amending the soils with phosphorus fertilizer (46% P2O5), reacting them in a plexiglass container (by removing a partition) and allowing the soils to mix with the overlying water column as they spread along the container bottom. The concentration of total phosphorus was measured at 1, 3, 6, 12, 24 and 36 hours after reaction occurred. A computer program was written to calculate the diffusion coefficients (D) for the different soil and fertilizer treatments. Correcting the D values for adsorption resulted in effective diffusion coefficients (De) values, averaged across all retardation factors, of 0.010; 0.0017 and 0.0124 cm^2/day for the 13,944; 9,295 and 4,648 mu g/1 phosphorus fertilizer kaolinite treatments and 0.0002; 0.0006 and 0.0013 cm^2/day for the 13,654; 9,103 and 4,552 mu g/1 phosphorus fertilizer bentonite treatments. The diffusion coefficients for the kaolinite soil treatments were consistently greater than those for the bentonite treatments.
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Date Issued
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1993
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PURL
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http://purl.flvc.org/fcla/dt/14928
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Subject Headings
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Kaolinite, Bentonite, Soils--Phosphorus content, Sedimentation analysis
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Format
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Document (PDF)
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Title
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The development and application of a numerical model for predicting the frequency response of the seabed from vertical profiles of sediment impedance.
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Creator
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Zhang, Jian Long., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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Interaction of normal incidence, wideband acoustic pulses with seabed is investigated to determine the acoustic frequency ranges that provide the most information about the sediment structure. An exact numerical model is developed for calculating the frequency response and impulse response of the seabed from an impedance profile of a sediment core. A database of impedance profiles from several ocean environments were studied to describe the shapes of commonly found impedance changes. The...
Show moreInteraction of normal incidence, wideband acoustic pulses with seabed is investigated to determine the acoustic frequency ranges that provide the most information about the sediment structure. An exact numerical model is developed for calculating the frequency response and impulse response of the seabed from an impedance profile of a sediment core. A database of impedance profiles from several ocean environments were studied to describe the shapes of commonly found impedance changes. The impulse response of the seabed is convolved with acoustic pulses to generate synthetic acoustic returns. The synthetic profiles are studied to determine the effect of operating frequency and bandwidth on resolution and on the accuracy of measuring impedance changes. This thesis explains why inversion procedures have failed to generate vertical impedance profiles of the seabed from normal incidence reflection data. The results of this work provide guidelines for selecting subbottom profiler array sizes and operating frequencies for quantitative sediment studies, and for subsampling cores.
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Date Issued
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1996
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PURL
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http://purl.flvc.org/fcla/dt/15293
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Subject Headings
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Marine sediments--Acoustic properties, Seismic reflection method
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Format
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Document (PDF)
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Title
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Comparison of the spatiotemporal variability of dredge material at two inletadjacent beaches.
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Creator
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Scheinkman, Austin, Briggs, Tiffany Roberts, Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
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Abstract/Description
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This study analyzed two different inlet management strategies being utilized in Palm Beach County and compared how the downdrift beaches were affected by those strategies throughout the year. Cross-sectional beach profiles, Digital Elevation Model comparisons, and subaerial volumetric change were analyzed for patterns in postplacement beach morphology. Trends in cross- and alongshore grainsize were also analyzed. In Boca Raton the inlet was dredged multiple times a month depending on the...
Show moreThis study analyzed two different inlet management strategies being utilized in Palm Beach County and compared how the downdrift beaches were affected by those strategies throughout the year. Cross-sectional beach profiles, Digital Elevation Model comparisons, and subaerial volumetric change were analyzed for patterns in postplacement beach morphology. Trends in cross- and alongshore grainsize were also analyzed. In Boca Raton the inlet was dredged multiple times a month depending on the level of infilling and the material was placed on the beach immediately downdrift of the inlet. The downdrift beach of the Boca Raton inlet underwent a cycle of shoreline advance in the summer and shoreline retreat in the winter. It was dominated by seasonal processes and its morphologic change was the direct result of shifts in the wind and waves without having a beach more than 60 to 80 meters over the course of the study. In Jupiter, the inlet was dredged on a near annual basis and the material was placed 600m south of the inlet. The size and scope of the larger one-time annual nourishment project resulted in beach widths upwards of 120 meters. The equilibration process that followed in both the cross- and alongshore are what dominated the morphological trends experienced at the site. The results of this study should help coastal managers without current inlet management strategies, compare and overview two different successful inlet management options. For future studies, researchers should extend the monitoring period and extend profiles to the depth of closure to capture. Sediment is a valuable resource, and it’s important for best management practices to maximize benefits and protect downdrift beaches for long-term resiliency of coastal communities.
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Date Issued
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2022
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PURL
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http://purl.flvc.org/fau/fd/FA00014010
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Subject Headings
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Inlets, Coastal zone management, Sediment, Beaches--Florida
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Format
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Document (PDF)
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Title
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MICROPLASTICS IN MANGROVE AND BEACH SEDIMENTS ON SOUTHEAST FLORIDA BARRIER ISLANDS.
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Creator
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O’Brien, Kayla Shae, Briggs, Tiffany Roberts, Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
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Abstract/Description
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Plastic pollution in the marine environment is a global occurrence. Microplastics have been documented in numerous marine systems and organisms. Coastal estuaries and beach systems are at high risk for microplastic pollution. The distribution, abundance, and hazards microplastics present in these marine environments is not fully understood but are widely recognized as needed to support efforts aiming to protect and enhance these extremely valuable marine systems. This project aimed to...
Show morePlastic pollution in the marine environment is a global occurrence. Microplastics have been documented in numerous marine systems and organisms. Coastal estuaries and beach systems are at high risk for microplastic pollution. The distribution, abundance, and hazards microplastics present in these marine environments is not fully understood but are widely recognized as needed to support efforts aiming to protect and enhance these extremely valuable marine systems. This project aimed to quantify the abundance and variation of microplastics in estuarine mangrove and open coast beach sediments on Southeast Florida barrier islands, which are vulnerable and important coastal ecosystems. Barrier islands serve as a buffer between Florida’s wetland environments, reefs, and other marine habitats and may serve as a conduit or temporary sink for microplastics entering the ocean. The microplastic pollution present in estuarine mangrove and open coast beach systems may also elucidate patterns of microplastic pollution in the surrounding or similar coastal environments. There have been no extensive studies or monitoring efforts evaluating microplastics in Southeast Florida barrier islands sediments, nor comparing geomorphic properties of an area on microplastic accumulation. Study sites included back barrier estuarine mangroves and open coast beaches at three regionally similar but geomorphically distinct study sites throughout Palm Beach County, Florida. The sites were sampled seasonally in 2022 (i.e., summer and winter) to quantify the spatiotemporal distribution of microplastics.
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Date Issued
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2023
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PURL
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http://purl.flvc.org/fau/fd/FA00014354
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Subject Headings
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Microplastics, Microplastics--Environmental aspects, Mangrove, Coastal sediments
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Format
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Document (PDF)
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Title
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THE BIOGEOCHEMICAL IMPORTANCE OF REACTIVE IRON IN FLORIDA BAY SEDIMENTS: BENTHIC-PELAGIC COUPLING AND SEASONAL SULFIDE DYNAMICS.
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Creator
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Thackston, Mason A., Beckler, Jordon, Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
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Abstract/Description
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Iron and manganese redox chemistry are important drivers of sulfur cycling in marine sediments. Florida Bay sediments are extremely sulfidic, having been attributed to mass mortality of seagrass and oxygen depletion in the water column. This research used conventional sediment analyses and a diagenetic model to infer the overall capacity for Florida Bay sediments to eliminate hydrogen sulfide and prevent high rates of sediment dissolved oxygen consumption via hydrogen sulfide reoxidation....
Show moreIron and manganese redox chemistry are important drivers of sulfur cycling in marine sediments. Florida Bay sediments are extremely sulfidic, having been attributed to mass mortality of seagrass and oxygen depletion in the water column. This research used conventional sediment analyses and a diagenetic model to infer the overall capacity for Florida Bay sediments to eliminate hydrogen sulfide and prevent high rates of sediment dissolved oxygen consumption via hydrogen sulfide reoxidation. Previous studies have suggested that iron is important for buffering hydrogen sulfide in Florida Bay sediments, while the results of this project show for the first time that this phenomenon is relevant only in specific locations and times of the year. However, my research indicates that Fe has the potential to sequester sulfides and minimize hypoxia in the Everglades system. Thus, under a scenario that greater amounts of Fe are delivered to Florida Bay sediments from freshwater flows under Everglades restoration, Fe could be a component of ecosystem management.
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Date Issued
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2024
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PURL
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http://purl.flvc.org/fau/fd/FA00014421
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Subject Headings
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Marine sediments, Florida Bay (Fla.), Sulfur cycle, Biogeochemical cycles
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Format
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Document (PDF)
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Title
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The collection, analysis and variation of nutrients in estuarine pore water.
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Creator
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Montgomery, John R., Zimmermann, Carl F., Price, Mary T., Harbor Branch Oceanographic Institute
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Date Issued
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1979
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PURL
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http://purl.flvc.org/FCLA/DT/3174480
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Subject Headings
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Estuaries, Estuarine sediments, Nutrient pollution of water, Pore water, Mud flat ecology
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Format
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Document (PDF)
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Title
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A comparison of ceramic cup and Teflon in situ samplers for nutrient pore water determinations.
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Creator
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Zimmermann, Carl F., Price, Mary T., Montgomery, John R., Harbor Branch Oceanographic Institute
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Date Issued
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1978
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PURL
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http://purl.flvc.org/FCLA/DT/3174478
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Subject Headings
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Estuaries, Estuarine sediments, Nutrient pollution of water, Water --Sampling, Pore water
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Format
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Document (PDF)
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Title
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Removal of suspended particles by fouling communities.
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Creator
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Mook, David H., Harbor Branch Oceanographic Institute
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Date Issued
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1981
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PURL
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http://purl.flvc.org/FCLA/DT/3350841
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Subject Headings
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Suspended sediments, Fouling, Fouling --Congresses, Microencapsulation, Suspension feeders --Ecology --Congresses, Sessile barnacles, Indian River (Fla.: Lagoon)
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Format
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Document (PDF)
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Title
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Organic determinations by ignition: caution advised.
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Creator
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Mook, David H., Hoskin, Charles M., Harbor Branch Oceanographic Institute
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Date Issued
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1982
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PURL
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http://purl.flvc.org/FCLA/DT/3353734
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Subject Headings
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Heating, Organic compounds--Analysis, Inorganic compounds--Analysis, Sediment, Clay
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Format
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Document (PDF)
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Title
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Production and off-bank transport of carbonate sediment, black rock, southwest Little Bahama Bank.
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Creator
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Hoskin, Charles M., Reed, John K., Mook, David H.
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Date Issued
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1986
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PURL
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http://purl.flvc.org/FCLA/DT/3353776
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Subject Headings
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Little Bahama Bank (Bahamas), Sediments (Geology), Carbonates, Echinometra lucunter, Halimeda, Chitons
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Format
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Document (PDF)
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Title
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Sediments from a living shelf-edge reef and adjacent area off central eastern Florida.
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Creator
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Hoskin, Charles M., Reed, John K., Mook, David H.
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Date Issued
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1987
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PURL
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http://purl.flvc.org/fau/fd/FA00007444
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Subject Headings
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East Florida, Oculinidae, Sediments (Geology), Coral reefs and islands--Florida
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Format
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Document (PDF)
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Title
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Residues of polychlorinated biphenyls and DDT in water and sediment of the Indian River Lagoon, Florida—1977-1978.
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Creator
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Wang, Tsen C., Johnson, R. S., Bricker, J. L., Harbor Branch Oceanographic Institute
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Date Issued
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1980
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PURL
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http://purl.flvc.org/FCLA/DT/3352187
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Subject Headings
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Indian River (Fla. : Lagoon), DDT (Insecticide), Polychlorinated biphenyls, River sediments, Water quality
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Format
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Document (PDF)
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Title
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Effects of a decomposing drift algal mat on sediment pore water nutrient concentrations in a Florida seagrass bed.
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Creator
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Zimmermann, Carl F., Montgomery, John R., Harbor Branch Oceanographic Institute
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Date Issued
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1984
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PURL
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http://purl.flvc.org/FCLA/DT/3350848
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Subject Headings
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Seagrasses, Pore water --Florida --Indian River, Algae --Ecology, Sediment control, Ammonium, Phosphate deposits
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Format
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Document (PDF)
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Title
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Production and nutrient dynamics of a Syringodium filiforme Kütz. seagrass bed in Indian River Lagoon, Florida.
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Creator
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Short, F. T., Montgomery, John R., Zimmermann, Carl F., Short, C. A., Harbor Branch Oceanographic Institute
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Date Issued
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1993
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PURL
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http://purl.flvc.org/FCLA/DT/3174032
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Subject Headings
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Seagrasses, Plant nutrients, Aquatic ecology, Sediment transport, Ammonium --Environmental aspects --Measurement
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Format
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Document (PDF)
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Title
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Residues of polychlorinated biphenyls and DDT in water and sediment of the St. Lucie Estuary, Florida, 1977.
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Creator
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Wang, Tsen C., Krivan, J. P., Jr., Johnson, R. S., Harbor Branch Oceanographic Institute
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Date Issued
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1979
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PURL
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http://purl.flvc.org/FCLA/DT/3352185
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Subject Headings
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Saint Lucie River Estuary (Fla.), DDT (Insecticide), Polychlorinated biphenyls, River sediments
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Format
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Document (PDF)
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Title
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Case history of a typical dredge-fill project in the northern Florida Keys—effects on water clarity, sedimentation rates and biota.
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Creator
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Griffin, G. M., Harbor Branch Oceanographic Institute
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Date Issued
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1974
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PURL
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http://purl.flvc.org/FCLA/DT/3352178
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Subject Headings
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Dredging, Effluent quality, Water quality, Florida Keys (Fla.), Sedimentation analysis, Biota
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Format
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Document (PDF)
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Title
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The role of density dependence in a marine infaunal community.
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Creator
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Wilson, W. Herbert, Jr., Harbor Branch Oceanographic Institute
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Date Issued
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1983
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PURL
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http://purl.flvc.org/FCLA/DT/3172803
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Subject Headings
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Benthic animals, Polychaeta, Spionidae, Pseudopolydora kempi, Reproduction, Asexual, Population biology, Marine sediments
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Format
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Document (PDF)
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Title
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Metabolites from the Marine-Derived Fungus Chromocleista sp. Isolated from a Deep-Water Sediment Sample Collected in the Gulf of Mexico.
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Creator
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Park, Young Chul, Gunasekera, Sarath P., Lopez, Jose V., McCarthy, Peter J., Wright, Amy E.
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Date Issued
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2006
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PURL
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http://purl.flvc.org/FCLA/DT/3164115
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Subject Headings
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Metabolites, Fungal metabolites, Marine fungi, X-ray crystallography, Marine sediments
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Format
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Document (PDF)
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Title
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Comparison of the anaerobic microbiota of deep-water Geodia spp. and sandy sediments in the Straits of Florida.
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Creator
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Bruck, W. M., Bruck, T. B., Self, W. T., Reed, John K., Nitecki, S. S., McCarthy, Peter J.
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Date Issued
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2010
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PURL
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http://purl.flvc.org/FCLA/DT/3351982
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Subject Headings
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Microbial ecology, Marine sediments, Florida, Straits of, Fluorescence in situ hybridization, Sponges
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Format
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Document (PDF)
Pages