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Full-Text Articles in Physical Sciences and Mathematics

No Reef Is An Island: Integrating Coral Reef Connectivity Data Into The Design Of Regional-Scale Marine Protected Area Networks, Steven R. Schill, George T. Raber, Jason J. Roberts, Eric A. Treml, Jorge Brenner, Patrick N. Halpin Dec 2015

No Reef Is An Island: Integrating Coral Reef Connectivity Data Into The Design Of Regional-Scale Marine Protected Area Networks, Steven R. Schill, George T. Raber, Jason J. Roberts, Eric A. Treml, Jorge Brenner, Patrick N. Halpin

Faculty Publications

We integrated coral reef connectivity data for the Caribbean and Gulf of Mexico into a conservation decision-making framework for designing a regional scale marine protected area (MPA) network that provides insight into ecological and political contexts. We used an ocean circulation model and regional coral reef data to simulate eight spawning events from 2008–2011, applying a maximum 30-day pelagic larval duration and 20% mortality rate. Coral larval dispersal patterns were analyzed between coral reefs across jurisdictional marine zones to identify spatial relationships between larval sources and destinations within countries and territories across the region. We applied our results in Marxan, …


Linkages Among Fluorescent Dissolved Organic Matter, Dissolved Amino Acids And Lignin-Derived Phenols In River-Influenced Ocean Margins, Youhei Yamashita, Cédric G. Fichot, Yuan Shen, Rudolf Jaffé, Ronald Benner Nov 2015

Linkages Among Fluorescent Dissolved Organic Matter, Dissolved Amino Acids And Lignin-Derived Phenols In River-Influenced Ocean Margins, Youhei Yamashita, Cédric G. Fichot, Yuan Shen, Rudolf Jaffé, Ronald Benner

Faculty Publications

Excitation emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) is commonly used to investigate the dynamics of dissolved organic matter (DOM). However, a lack of direct comparisons with known biomolecules makes it difficult to substantiate the molecular composition of specific fluorescent components. Here, coincident surface-water measurements of EEMs, dissolved lignin, and total dissolved amino acids (TDAA) acquired in the northern Gulf of Mexico were used to investigate the relationships between specific fluorescent components and DOM biomolecules. Two terrestrial humic-like components identified by EEM-PARAFAC using samples obtained from river to offshore waters were strongly linearly correlated with dissolved …


Abundance, Stable Isotopic Composition, And Export Fluxes Of Doc, Poc, And Dic From The Lower Mississippi River During 2006-2008, Yihua Cai, Laodong Guo, Xuri Wang, George Aiken Nov 2015

Abundance, Stable Isotopic Composition, And Export Fluxes Of Doc, Poc, And Dic From The Lower Mississippi River During 2006-2008, Yihua Cai, Laodong Guo, Xuri Wang, George Aiken

Faculty Publications

Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its …


Effects Of Oil-Contaminated Sediments On Submerged Vegetation: An Experimental Assessment Of Ruppia Maritima, Charles W. Martin, Lauris O. Hollis, R. Eugene Turner Oct 2015

Effects Of Oil-Contaminated Sediments On Submerged Vegetation: An Experimental Assessment Of Ruppia Maritima, Charles W. Martin, Lauris O. Hollis, R. Eugene Turner

Faculty Publications

Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked …


Indirect Evidence For Substantial Damping Of Low-Mode Internal Tides In The Open Ocean, Joseph K. Ansong, Brian K. Arbic, Maarten C. Buijsman, James G. Richman, Jay F. Shriver, Alan J. Wallcraft Sep 2015

Indirect Evidence For Substantial Damping Of Low-Mode Internal Tides In The Open Ocean, Joseph K. Ansong, Brian K. Arbic, Maarten C. Buijsman, James G. Richman, Jay F. Shriver, Alan J. Wallcraft

Faculty Publications

A global high-resolution ocean circulation model forced by atmospheric fields and the M2 tidal constituent is used to explore plausible scenarios for the damping of low-mode internal tides. The plausibility of different damping scenarios is tested by comparing the modeled barotropic tides with TPXO8, a highly accurate satellite-altimetry-constrained tide model, and by comparing the modeled coherent baroclinic tide amplitudes against along-track altimetry. Five scenarios are tested: (1) a topographic internal wave drag, argued here to represent the breaking of unresolved high vertical modes, applied to the bottom flow (default configuration), (2) a wave drag applied to the barotropic flow, …


Chesapeake Bay Nitrogen Fluxes Derived From A Land-Estuarine Ocean Biogeochemical Modeling System: Model Description, Evaluation, And Nitrogen Budgets, Yang Feng, Marjorie A.M. Friedrichs, John Wilkin, Hanqin Tian, Qichun Yang, Eileen E. Hofmann, Jerry D. Wiggert, Raleigh R. Hood Aug 2015

Chesapeake Bay Nitrogen Fluxes Derived From A Land-Estuarine Ocean Biogeochemical Modeling System: Model Description, Evaluation, And Nitrogen Budgets, Yang Feng, Marjorie A.M. Friedrichs, John Wilkin, Hanqin Tian, Qichun Yang, Eileen E. Hofmann, Jerry D. Wiggert, Raleigh R. Hood

Faculty Publications

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001–2005 was conducted to quantify the Chesapeake Bay nitrogen …


The Evolution Of Mode-2 Nonlinear Internal Waves Over The Northern Heng-Chun Ridge South Of Taiwan, S.R. Ramp, Y.J. Yang, D.B. Reeder, Maarten C. Buijsman, F.L. Bahr Jul 2015

The Evolution Of Mode-2 Nonlinear Internal Waves Over The Northern Heng-Chun Ridge South Of Taiwan, S.R. Ramp, Y.J. Yang, D.B. Reeder, Maarten C. Buijsman, F.L. Bahr

Faculty Publications

Two research cruises were conducted from the R/V OCEAN RESEARCHER 3 during 05–16 August 2011 to study the generation and propagation of high-frequency nonlinear internal waves (NLIWs) over the northern Heng-Chun Ridge south of Taiwan. The primary study site was on top of a smaller ridge about 15 km wide by 400 m high atop the primary ridge, with a sill depth of approximately 600 m. A single mooring was used in conjunction with shipboard observations to sample the temperature, salinity and velocity structure over the ridge. All the sensors observed a profusion of mode-2 NLIWs. Some of the waves …


Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner Mar 2015

Marine Sequestration Of Carbon In Bacterial Metabolites, Oliver J. Lechtenfeld, Norbert Hertkorn, Yuan Shen, Matthias Witt, Ronald Benner

Faculty Publications

Linking microbial metabolomics and carbon sequestration in the ocean via refractory organic molecules has been hampered by the chemical complexity of dissolved organic matter (DOM). Here, using bioassay experiments and ultra-high resolution metabolic profiling, we demonstrate that marine bacteria rapidly utilize simple organic molecules and produce exometabolites of remarkable molecular and structural diversity. Bacterial DOM is similar in chemical composition and structural complexity to naturally occurring DOM in sea water. An appreciable fraction of bacterial DOM has molecular and structural properties that are consistent with those of refractory molecules in the ocean, indicating a dominant role for bacteria in shaping …


Dust Deposition In The Eastern Indian Ocean: The Ocean Perspective From Antarctica To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, Clifton Buck, William Landing Mar 2015

Dust Deposition In The Eastern Indian Ocean: The Ocean Perspective From Antarctica To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, Clifton Buck, William Landing

Faculty Publications

Atmospheric deposition is an important but still poorly constrained source of trace micronutrients to the open ocean because of the dearth of in situ measurements of total deposition (i.e., wet + dry deposition) in remote regions. In this work, we discuss the upper ocean distribution of dissolved Fe and Al in the eastern Indian Ocean along a 95°E meridional transect spanning the Antarctic margin to the Bay of Bengal. We use the mixed layer concentration of dissolved Al in conjunction with empirical data in a simple steady state model to produce 75 estimates of total dust deposition that we compare …


Dissolved Fe And Al In The Upper 1000 M Of The Eastern Indian Ocean: A High‐Resolution Transect Along 95°E From The Antarctic Margin To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, William Landing, Peter Morton, Clifton Buck, Pamela Barrett, Joseph Resing Mar 2015

Dissolved Fe And Al In The Upper 1000 M Of The Eastern Indian Ocean: A High‐Resolution Transect Along 95°E From The Antarctic Margin To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, William Landing, Peter Morton, Clifton Buck, Pamela Barrett, Joseph Resing

Faculty Publications

A high‐resolution section of dissolved iron (dFe) and aluminum (dAl) was obtained along ~95°E in the upper 1000 m of the eastern Indian Ocean from the Antarctic margin (66°S) to the Bay of Bengal (18°N) during the U.S. Climate Variability and Predictability (CLIVAR) CO2 Repeat Hydrography I08S and I09N sections (February–April 2007). In the Southern Ocean, low concentrations of dAl (<1 n M) reflect the negligible dust inputs impacting the water masses subducted in the circumpolar domain. The low dAl concentrations characterizing the Southern Ocean terminate near 45°S, probably because of the advection of subtropical water masses that received dust and sedimentary inputs in their formation region. Our subsurface dFe data near the southern Kerguelen Plateau were significantly higher than historical observations in other Indian sectors of the Southern Ocean. We surmise that the offshore advection of dFe‐rich waters along the western flank of the southern Kerguelen plateau and enhanced vertical mixing could contribute to this elevated subsurface dFe inventory. Elevated subsurface particulate and dFe levels downstream of the northern Kerguelen Plateau may reflect long‐range lateral transport from the plateau's sediments and/or remineralization inputs. At the northern edge of the south Indian subtropical gyre, the deposition of Australian dust, possibly combined with the advection of dAl‐enriched waters from the Indonesian Throughflow, creates a region of elevated dAl in the upper 400 m but without a corresponding enrichment in dFe. In the northern Indian Ocean, the South Equatorial Current constitutes a remarkable biogeochemical front separating the oxygen‐rich and dFe‐poor subtropical gyre waters from the dFe‐rich and oxygen‐depleted waters of the northern Indian Ocean. By tracing the accumulation of macronutrients and dFe along the advective pathway of Indian Central Water, we show that the central waters of the northern Indian Ocean receive excess dFe in addition to that produced by remineralization inputs. The resuspension of shelf sediments and release of pore waters probably contribute to the elevated dFe and dAl levels observed below the highly stratified upper layers of the Bay of Bengal.