Oceanography Commons^™

Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton

OES Faculty Publications

The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits …

Are Long Tide Gauge Records In The Wrong Place To Measure Global Mean Sea Level Rise?, P. R. Thompson, B. D. Hamlington, F. W. Landerer, S. Adhikari

CCPO Publications

Ocean dynamics, land motion, and changes in Earth's gravitational and rotational fields cause local sea level change to deviate from the rate of global mean sea level rise. Here we use observations and simulations of spatial structure in sea level change to estimate the likelihood that these processes cause sea level trends in the longest and highest-quality tide gauge records to be systematically biased relative to the true global mean rate. The analyzed records have an average twentieth century rate of approximately 1.6 mm/yr, but based on the locations of these gauges, we show that the simple average underestimates the …

Developing Priority Variables (“Ecosystem Essential Ocean Variables” — Eeovs) For Observing Dynamics And Change In Southern Ocean Ecosystems, Andrew J. Constable, Daniel P. Costa, Oscar Schofield, Louise Newman, Edward R. Urban Jr., Elizabeth A. Fulton, Jessica Melbourne-Thomas, Tosca Ballerini, Philip W. Boyd, Angelika Brandt, Eileen E. Hofmann

CCPO Publications

Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect …

Modelling The Response Of Ice Shelf Basal Melting To Different Ocean Cavity Environmental Regimes, David E. Gwyther, Eva A. Cougnon, Benjamin K. Galton-Fenzi, Jason L. Roberts, John R. Hunter, Michael S. Dinniman

CCPO Publications

We present simulation results from a version of the Regional Ocean Modeling System modified for ice shelf/ocean interaction, including the parameterisation of basal melting by molecular diffusion alone. Simulations investigate the differences in melting for an idealised ice shelf experiencing a range of cold to hot ocean cavity conditions. Both the pattern of melt and the location of maximum melt shift due to changes in the buoyancy-driven circulation, in a different way to previous studies. Tidal forcing increases both the circulation strength and melting, with the strongest impact on the cold cavity case. Our results highlight the importance of including …

Modeling Ice Shelf/Ocean Interaction In Antarctica: A Review, Michael S. Dinniman, Xylar S. Asay-Davis, Benjamin K. Galton-Fenzi, Paul R. Holland, Adrian Jenkins, Ralph Timmerman

CCPO Publications

The most rapid loss of ice from the Antarctic Ice Sheet is observed where ice streams flow into the ocean and begin to float, forming the great Antarctic ice shelves that surround much of the continent. Because these ice shelves are floating, their thinning does not greatly influence sea level. However, they also buttress the ice streams draining the ice sheet, and so ice shelf changes do significantly influence sea level by altering the discharge of grounded ice. Currently, the most significant loss of mass from the ice shelves is from melting at the base (although iceberg calving is a …

An Ongoing Shift In Pacific Ocean Sea Level, B. D. Hamlington, S. H. Cheon, P. R. Thompson, M. A. Merrifield, R. S. Nerem, R. R. Leben, K.-Y. Kim

CCPO Publications

Based on the satellite altimeter data, sea level off the west coast of the United States has increased over the past 5 years, while sea level in the western tropical Pacific has declined. Understanding whether this is a short‐term shift or the beginning of a longer‐term change in sea level has important implications for coastal planning efforts in the coming decades. Here, we identify and quantify the recent shift in Pacific Ocean sea level, and also seek to describe the variability in a manner consistent with recent descriptions of El Nino‐Southern Oscillation (ENSO) and particularly the Pacific Decadal Oscillation (PDO). …

Impact Of Model Resolution For On-Shelf Heat Transport Along The West Antarctic Peninsula, Jennifer A. Graham, Michael S. Dinniman, John M. Klinck

CCPO Publications

The flux of warm deep water onto Antarctic continental shelves plays a vital role in determining water mass properties adjacent to the continent. A regional model, with two different grid resolutions, has been used to simulate ocean processes along the West Antarctic Peninsula. At both 4 km and 1.5 km resolution, the model reproduces the locations of warm intrusions, as shown through comparison with observations from instrumented seals. However, the 1.5 km simulation shows greater on-shelf heat transport, leading to improved representation of heat content on the shelf. This increased heat transport is associated with increased eddy activity, both at …

Assessing The Impact Of Vertical Land Motion On Twentieth Century Global Mean Sea Level Estimates, B. D. Hamlington, P. Thompson, W. C. Hammond, G. Blewitt, R. D. Ray

CCPO Publications

Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does …

Mechanism Of Seasonal Arctic Sea Ice Evolution And Arctic Amplification, Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, Jinju Kim

CCPO Publications

Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea …

Geospatial Approaches To Support Pelagic Conservation Planning And Adaptive Management, L. M. Wedding, Sara M. Maxwell, D. Hyrenbach, D. C. Dunn, J. J. Roberts, D. Briscoe, E. Hines, P. N. Halpin

Biological Sciences Faculty Publications

Place-based management in the open ocean faces unique challenges in delineating boundaries around temporally and spatially dynamic systems that span broad geographic scales and multiple management jurisdictions, especially in the 'high seas'. Geospatial technologies are critical for the successful design of pelagic conservation areas, because they provide information on the spatially and temporally dynamic oceanographic features responsible for driving species distribution and abundance in the open ocean, the movements of protected species, and the spatial patterns of distribution of potential threats. Nevertheless, there are major challenges to implementing these geospatial approaches in the open ocean. This Theme Section seeks to …

Hydrodynamic Variability In A Microtidal Coastal Bay Geographically Susceptible To North East Trade Winds, Israel Medina-Gómez, Cecilia Enríquez, Björn Kjerfve, Ismael Mariño, Jorge Herrera-Silveira

Gulf and Caribbean Research

The ecological integrity and overall health conditions of natural coastal systems are largely based upon the balance among physical processes. The objective of this study was to assess the effects of tides and winds on the water level variability, circulation patterns, and turnover time in Bahia de la Ascension (BA), a shallow, tropical coastal bay in the Mexican Caribbean prone to the influence of Trade winds due to its geographical location. The analysis of the hydrodynamics of BA using a 2D numerical model indicates that the tidal flow in the inlets and central basin of the bay vary by tidal …

Decadal Bering Sea Seascape Change: Consequences For Pacific Walruses And Indigenous Hunters, G. Carleton Ray, Gary L. Hufford, James E. Overland, Igor Krupnik, Jerry Mccormick-Ray, Karen Frey, Elizabeth Labunski

Geography

The most signifi cant factors currently affecting the Pacifi c walrus (Odobenus rosmarus divergens) population are climate change and consequent changes in sea-ice morphology and dynamics. This paper integrates recent physical sea-ice change in the Bering Sea with biological and ecological conditions of walruses in their winter-spring reproductive habitat. Historically, walrus in winter-spring depended on a critical mass of sea-ice habitat to optimize social networking, reproductive fi tness, feeding behavior, migration, and energetic effi ciency. During 2003-2013, our cross-disciplinary, multiscale analysis from shipboard observations, satellite imagery, and ice-fl oe tracking, reinforced by information from indigenous subsistence hunters, documented change of …

Responses Of Marine Organisms To Climate Change Across Oceans, Elvira S. Poloczanska, Michael T. Burrows, Christipher J. Brown, Jorge G. Molinos, Benjamin S. Halpern, Ove Hoegh-Guldberg, Carrie V. Kappel, Philippa J. Moore, Anthony Richardson, David S. Schoeman, William J. Sydeman

Research outputs 2014 to 2021

Climate change is driving changes in the physical and chemical properties of the ocean that have consequences for marine ecosystems. Here, we review evidence for the responses of marine life to recent climate change across ocean regions, from tropical seas to polar oceans. We consider observed changes in calcification rates, demography, abundance, distribution, and phenology of marine species. We draw on a database of observed climate change impacts on marine species, supplemented with evidence in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We discuss factors that limit or facilitate species' responses, such as fishing pressure, the …

Are We Missing Important Areas In Pelagic Marine Conservation? Redefining Conservation Hotspots In The Ocean, Dana K. Briscoe, Sara M. Maxwell, Raphael Kudela, Larry B. Crowder

Biological Sciences Faculty Publications

The protection of biodiversity is one of the most important goals in terrestrial and marine conservation. Marine conservation approaches have traditionally followed the example of terrestrial initiatives. However, patterns, processes, habitats, and threats differ greatly between the 2 systems - and even within the marine environment. As a result, there is still a lack of congruence as to how to best identify and prioritize conservation approaches moving from the static terrestrial and nearshore realm into a more fluid, 3-dimensional pelagic realm. To address this problem, we investigate how the conservation science literature has been used to inform and guide management …

Historical Processes And Contemporary Ocean Currents Drive Genetic Structure In The Seagrass Thalassia Hemprichii In The Indo-Australian Archipelago, Udhi E. Hernawan, Kor-Jent Van Dijk, Gary A. Kendrick, Ming Feng, Edward Biffin, Paul Lavery, Kathryn Mcmahon

Research Datasets

Understanding spatial patterns of gene flow and genetic structure is essential for the conservation of marine ecosystems. Contemporary ocean currents and historical isolation due to Pleistocene sea-level fluctuations have been predicted to influence the genetic structure in marine populations. In the Indo-Australian Archipelago (IAA), the world's hotspot of marine biodiversity, seagrasses are a vital component but population genetic information is very limited. Here, we reconstructed the phylogeography of the seagrass Thalassia hemprichii in the IAA based on single nucleotide polymorphisms (SNPs) and then characterised the genetic structure based on a panel of 16 microsatellite markers. We further examined the relative …

Sea Surface Temperature Variability In The Central-Western Mediterranean Sea During The Last 2700 Years: A Multi-Proxy And Multi-Record Approach, Merce Cisneros, Isabel Cacho, Jaime Frigola, Miquel Canals, Pere Masque, Belen Martrat, Marta Casado, Joan Grimalt, Leopoldo Pena, Giulia Margaritelli, Fabrizio Lirer

Research outputs 2014 to 2021

This study presents the reconstructed evolution of sea surface conditions in the central-western Mediterranean Sea during the late Holocene (2700 years) from a set of multi-proxy records as measured on five short sediment cores from two sites north of Minorca (cores MINMC06 and HER-MC-MR3). Sea surface temperatures (SSTs) from alkenones and Globigerina bulloides Mg / Ca ratios are combined with δ¹⁸O measurements in order to reconstruct changes in the regional evaporation–precipitation (E–P) balance. We also revisit the G. bulloides Mg / Ca–SST calibration and re-adjusted it based on a set of core-top measurements from the western Mediterranean Sea. …

Individual And Population-Level Responses To Ocean Acidification, Ben P. Harvey, Niall J. Mckeown, Samuel P. Rastrick, Camilla Bertolini, Andy Foggo, Helen Graham, Jason M. Hall-Spencer, Marco Milazzo, Paul W. Shaw, Daniel P. Small, Philippa J. Moore

Research outputs 2014 to 2021

Ocean acidification is predicted to have detrimental effects on many marine organisms and ecological processes. Despite growing evidence for direct impacts on specific species, few studies have simultaneously considered the effects of ocean acidification on individuals (e.g. consequences for energy budgets and resource partitioning) and population level demographic processes. Here we show that ocean acidification increases energetic demands on gastropods resulting in altered energy allocation, i.e. reduced shell size but increased body mass. When scaled up to the population level, long-term exposure to ocean acidification altered population demography, with evidence of a reduction in the proportion of females in the …

Impact Of Mooring Activities On Carbon Stocks In Seagrass Meadows, Oscar Serrano, Radhiyah Ruhon, Paul S. Lavery, Gary A. Kendrick, Sharyn Hickey, Pere Masque, Ariane Arias-Ortiz, Andy Steven, Carlos M. Duarte

Research Datasets

The database compiles published data (in Serrano et al. 2016, Scientific Reports, in press) on biogeochemical characteristics (density, organic carbon, calcium carbonate, stable carbon isotopes and sediment grain size) of sediments underneath seagrass meadows and adjacent un-vegetated patches after mooring disturbances in Rottnest Island (Perth, Western Australia). The dataset compiles data on biogeochemical sediment characteristics for a total of 16 cores, 50 cm-long (4 cores from seagrass meadows and 4 cores from adjacent bare sediments at Thompson Bay, and 4 cores from seagrass meadows and 4 cores from adjacent bare sediments at Stark Bay).

Seagrass Sediments Reveal The Long-Term Deterioration Of An Estuarine Ecosystem, Oscar Serrano, Paul S. Lavery, Pere Masque, Karina Inostroza, James Bongiovanni, Carlos Duarte

Research Datasets

The database compiles published data (in Serrano et al. 2016, Global Change Biology, doi:10.1111/gcb.13195) on temporal trends in biogeochemical variables in the Posidonia australis sediment core from Oyster Harbour, Western Australia. The core studied encompasses the last 500 years of history. Data on dry bulk density, carbonate content, sedimentso.

Variability In The Carbon Storage Of Seagrass Habitats And Its Implications For Global Estimates Of Blue Carbon Ecosystem Service, Paul Lavery, Miguel-Angel Mateo, Oscar Serrano, Mohammad Rozaimi

Research Datasets

The dataset compiles published data (in Lavery et al. 2013, PLoS ONE 8(9): e73748. doi:10.1371/journal.pone.0073748) on biogeochemical variables (organic matter, organic carbon and CO3 contents, and stable carbon isotope signatures of the organic carbon) in sediment core from seagrass meadows in Australia. The cores studied were up to 29 cm long, and ecompass tropical, subtropical and temperate seagrass meadows in intertidal and subtidal habitats.

A Statistical Model For The Prediction Of Dissolved Oxygen Dynamics And The Potential For Hypoxia In The Mississippi Sound And Bight, Andreas Moshogianis

Master's Theses

Hypoxia events occur when dissolved oxygen concentrations fall below the minimum threshold (dissolved oxygen concentrations < 2 mg O₂ L^-1) necessary to avoid respiratory distress among aquatic organisms. In the Mississippi Sound and Bight, hypoxia is most prevalent from late-spring through late summer. Since hypoxia events can have dramatic effects on coastal fisheries, the spatial and temporal magnitude of hypoxia presents a clear threat to the productive fisheries in the northern Gulf of Mexico. Long-term hydrographic data were collected from eight sampling stations on a monthly basis from January 2009 to December 2011 along a cross-shelf transect from the mouth of …

Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa

Dissertations

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented.

The P-R model illustrates the decreasing …

A Study On The Integration Of Multivariate Metocean, Ocean Circulation, And Trajectory Modeling Data With Static Geographic Information Systems For Better Marine Resources Management And Protection During Coastal Oil Spill Response – A Case Study And Gap Analysis On Northeastern Gulf Of Mexico Tidal Inlets, Richard Ray Knudsen

USF Tampa Graduate Theses and Dissertations

The Oil Pollution Act of 1990 requires the development of Regional and Area Contingency Plans. For more than 20 years, the State of Florida, under both the Department of Environmental Protection and the Florida Fish and Wildlife Commission, has worked closely with the U.S. Coast Guard and the National Oceanic and Atmospheric Administration to develop these plans for coastal and marine oil spill response. Current plans, developed with local, state and federal stakeholder input, use geographic information systems (GIS) data such as location and extent of sensitive ecological, wildlife, and human-use features (termed Environmental Sensitivity Index data), pre-defined protection priorities, …

Understanding Climate Change And Sea Level: A Case Study Of Middle School Student Comprehension And An Evaluation Of Tide Gauges Off The Panama Canal In The Pacific Ocean And Caribbean Sea, Juan Carlos Millan-Otoya

USF Tampa Graduate Theses and Dissertations

The present study had two main objectives. The first was to determine the degree of understanding of climate change, sea level and sea level rise among middle school students. Combining open-ended questions with likert-scaled questions, we identified student conceptions on these topics in 86 students from 7^th and 8^th grades during 2012 and 2013 before and after implementing a Curriculum Unit (CU). Additional information was obtained by adding drawings to the open-ended questions during the second year to gauge how student conceptions varied from a verbal and a visual perspective. Misconceptions were identified both pre- and post-CU among …

8000 Years Of Environmental Evolution Of Barrier–Lagoon Systems Emplaced In Coastal Embayments (Nw Iberia), Rita González-Villanueva, Marta Pérez-Arlucea, Susana Costas, Roberto Bao, Xose L. Otero, Ronald J. Goble

Department of Earth and Atmospheric Sciences: Faculty Publications

The rocky and indented coast of NW Iberia is characterized by the presence of highly valuable and vulnerable, small and shallow barrier– lagoon systems structurally controlled. The case study was selected to analyse barrier–lagoon evolution based on detailed sedimentary architecture, chronology, geochemical and biological proxies. The main objective is to test the hypothesis of structural control and the significance at regional scale of any highenergy event recorded. This work is also aimed at identifying general patterns and conceptualizing the formation and evolution of this type of coastal systems. The results allowed us to establish a conceptual model of Holocene evolution …

Temporal Variation In Optical Properties Of Chromophoric Dissolved Organic Matter (Cdom) In Southern California Coastal Waters With Nearshore Kelp And Seagrass, Catherine D. Clark, Warren J. De Bruyn, Paige Aiona

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Optical properties of chromophoric dissolved organic matter (CDOM) were measured in surf zone waters in diurnal field studies at a Southern California beach with nearshore kelp and seagrass beds and intertidal plant wrack. Absorption coefficients (aCDOM(300 nm)) ranged from 0.35 m21 to 3.7 m21 with short-term variability<1 h, increases at ebb and flood tides and higher values (6 m21) during an offshore storm event. Spectral slopes (S) ranged from 0.0028 nm21 to 0.017 nm21, with higher values after the storm; S was generally inversely correlated with aCDOM(300 nm). 3-D excitation–emission matrix spectra (EEMs) for samples with lower S values had humic-type peaks associated with terrestrial material (A, C), marine microbial material (M) and protein peaks, characteristic of freshly produced organic material. Samples with high S values had no or reduced protein peaks, consistent with aged material. Fluorescent indexes (f450/f500 >2.5, BIX>1.1) were consistent with microbial aquatic sources. Leachates of senescent kelp and seagrass had protein and humic-type EEM peaks. After solar simulator irradiation (4 h), protein peaks rapidly photochemically degraded, humic-type peak C increased in intensity and peak M disappeared. Optical characteristics of kelp leachates were most similar to field samples, …

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 …

Sea Level Rise In Virginia – Causes, Effects And Response, Tal Ezer, Larry P. Atkinson

Virginia Journal of Science

Sea level rise (SLR) along Virginia’s coasts and around the Chesapeake Bay as measured by tide gauges is analyzed and discussed. It is shown that the SLR rates vary between one location to another and in most locations the rates increase over time (i.e., SLR is accelerating). The latest science of SLR is reviewed and the causes of the high SLR rates in Virginia are discussed. The impacts of land subsidence and ocean currents (changes in the Gulf Stream in particular) on sea level are especially notable and important for predicting future SLR in Virginia. The consequences of SLR on …

Crowdsourcing Global Wastewater Data, Don Mosteller, Sam Cohen, Cory Nestor, Angel Hsu, Omar Malik

Yale Day of Data

No time to waste: Crowdsourcing global wastewater treatment data

Worldwide, over 80 percent of wastewater is discharged into water bodies without undergoing treatment, severely impairing human well-being and ecosystem vitality along the way. National performance on wastewater treatment is difficult to quantify and is poorly understood due to a lack of common definitions, poor data collection standards, and limited historical data. To address this, the Yale Environmental Performance Index (EPI), a research group that produces a biennial ranking of country-level environmental performance, developed a first-of-its kind national wastewater treatment indicator.[1]

The indicator assesses wastewater treatment performance for 183 countries, …

Coastal Sediment Elevation Change Following Anthropogenic Mangrove Clearing, Heather Lyn Hayden, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment “traps” catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five …