Oceanography Commons^™

Fema Region Iii Coastal Storm Surge Study, Mike Forte, Jeff Hanson, Michelle Hamor

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

Exploration Of Eratosthenes Seamount – A Continental Fragment Being Forced Down An Oceanic Trench, Garrett Mitchell, Larry A. Mayer, Katherine L.C. Bell, Nicole A. Raineault, Chris Roman, Robert D. Ballard, Kelsey Cornwell, Al Hine, Eugene Shinn, Iordanis Dimitriadis, Onac Bogdan

Center for Coastal and Ocean Mapping

No abstract provided.

Uncoupling Between Dinitrogen Fixation And Primary Productivity In The Eastern Mediterranean Sea, Eyal Rahav, Barak Herut, Noga Stambler, Edo Bar-Zeev, Margaret R. Mulholland

OES Faculty Publications

In the nitrogen (N)-impoverished photic zones of many oceanic regions, prokaryotic organisms fixing atmospheric dinitrogen (N₂; diazotrophs) supply an essential source of new nitrogen and fuel primary production. We measured dinitrogen fixation and primary productivity (PP) during the thermally stratified summer period in different water regimes of the oligotrophic eastern Mediterranean Sea, including the Cyprus Eddy and the Rhodes Gyre. Low N₂ fixation rates were measured (0.8-3.2μmol N m-2 d-1) excluding 10-fold higher rates in the Rhodes Gyre and Cyprus Eddy (~20μmol N m^-2 d^-1). The corresponding PP increased from east to west (200-2500μmol …

Effects Of Flow Rates And Composition Of The Filter, And Decay/Ingrowth Correction Factors Involved With The Determination Of In Situ Particulate 210Po And 210Pb In Seawater, Mark Baskaran, Thomas Church, Gi Hong, Anupam Kumar, Ma Qiang, Hui Choi, Sylvain Rigaud, Kanchan Maiti

Environmental Science and Geology Faculty Research Publications

Accurate measurements of particulate ²¹⁰Po (²¹⁰Po_p) and ²¹⁰Pb (²¹⁰Pb_p) are required in the investigation of (i) partitioning of Po and Pb between particulate and dissolved phases and (ii) export estimates of carbon and other key trace metals from the euphotic zone via sinking particulate matter. Based on the intercomparison of different composition of the filter material (QMA, Supor, Millipore, and Pall GN6) and flow rates (2 to 8 L min), we show how these factors affect the measured concentrations of ²¹⁰Po_p and ²¹⁰Pb_p and their activity …

Preparing For The Rising Tide, Ellen Douglas, Paul Kirshen, Vivian Li, Chris Watson, Julie Wormser

Environmental, Earth, and Ocean Sciences Faculty Publication Series

On October 29, 2012, one of the largest Atlantic basin storms in recorded history hit the East Coast. Although Superstorm Sandy centered around New Jersey and New York when it made landfall, the massive storm system spanned 1,000 miles north to south, over three times the size of a typical hurricane.

Luckily for Boston, Sandy’s storm surge hit the city near low tide, causing relatively minor coastal flooding. Had the storm hit 5½ hours earlier, 6.6 percent of the city could have been flooded, with floodwaters reaching City Hall.

Events such as Superstorm Sandy highlight the growing relevance of climate …

Gulf Stream's Induced Sea Level Rise And Variability Along The U.S. Mid-Atlantic Coast, Tal Ezer, Larry P. Atkinson, William B. Corlett, Jose L. Blanco

CCPO Publications

Recent studies indicate that the rates of sea level rise (SLR) along the U. S. mid-Atlantic coast have accelerated in recent decades, possibly due to a slowdown of the Atlantic Meridional Overturning Circulation (AMOC) and its upper branch, the Gulf Stream (GS). We analyzed the GS elevation gradient obtained from altimeter data, the Florida Current transport obtained from cable measurements, the North Atlantic Oscillation (NAO) index, and coastal sea level obtained from 10 tide gauge stations in the Chesapeake Bay and the mid-Atlantic coast. An Empirical Mode Decomposition/Hilbert-Huang Transformation (EMD/HHT) method was used to separate long-term trends from oscillating modes. …

Differential Responses Of Ammonia-Oxidizing Archaea And Bacteria To Long-Term Fertilization In A New England Salt Marsh., Xuefeng Peng, Erik Yando, Erica Hiildebrand, Courtney Dwyer, Anne Kearney, Alex Waciega, Ivan Valiela, Anne E. Bernhard

Biology Faculty Publications

Since the discovery of ammonia-oxidizing archaea (AOA), new questions have arisen about population and community dynamics and potential interactions between AOA and ammonia-oxidizing bacteria (AOB). We investigated the effects of long-term fertilization on AOA and AOB in the Great Sippewissett Marsh, Falmouth, MA, USA to address some of these questions. Sediment samples were collected from low and high marsh habitats in July 2009 from replicate plots that received low (LF), high (HF), and extra high (XF) levels of a mixed NPK fertilizer biweekly during the growing season since 1974. Additional untreated plots were included as controls (C). Terminal restriction fragment …

Fall 2013, Nova Southeastern University

Currents

No abstract provided.

The Global Sustainability Transition: It Is More Than Changing Light Bulbs, Michael P. Weinstein, R. Eugene Turner, Carles Ibanez

Faculty Publications

Current policies and norms to reconcile human demands for resources with the Earth’s ability to supply them have resulted in practices that mainly treat the symptoms of unsustainability rather than their underlying causes. Moreover, the increase in our knowledge about humankind’s role in ecosystems is not keeping pace with our understanding of the consequences of our actions, resulting in a deepening inability to address sustainability issues. The extreme complexity and intricate workings of the world require the expansion of our mental models in a systems-thinking framework if we are to realize a sustainable place for humans in it. The challenge …

Degradable Plastics And Solid Waste Management Systems, David J. Tonjes, Krista L. Thyberg

Technology & Society Faculty Publications

Plastics, which are woven into the fabric of modern life, have consequential impacts on the environment. Many of these are associated with end-of-lifetime processes, and include chemical contamination of the environment and effects from litter. Plastics also complicate waste management processes, causing contamination in composting operations, and having poor recovery rates through recycling. Plastics that are not as biologically recalcitrant, that decompose when use is done, have been perceived as solutions to at least some of these problems. The first generation of degradable plastics did not meet marketing claims; some of the more recent formulations, partly as a consequence of …

Arsenic And Phosphorus Biogeochemistry In The Ocean: Arsenic Species As Proxies For P-Limitation, Oliver Wurl, Louise Zimmer, Gregory A. Cutter

OES Faculty Publications

Arsenic and phosphorus are biochemically very similar, and hence arsenate (As⁵⁺) is toxic by interfering with the energy metabolism, in particular during P limitation. However, many phytoplankton detoxify As by reducing arsenate to arsenite (As³⁺), and/or methylating it to mono and dimethyl As. Such As detoxification becomes operative in oligotrophic waters when phosphate concentrations are below those for As; therefore, we evaluated the potential use of these detoxification products as indicators of P-limitation by measuring As speciation during the US GEOTRACES North Atlantic transect. The distribution of As³⁺ concentrations in surface waters is similar to …

Intercalibraton In Chemical Oceanography-- Getting The Right Number, Gregory A. Cutter

OES Faculty Publications

Intercalibration has a strict metrological definition, but in brief, it's an open sharing of methods and results between laboratories to achieve the most accurate data with the fewest random and systematic errors. In the field of chemical oceanography where concentrations of many constituents can be in the nano- to picomolar range, the salt water matrix can be difficult to analyze, and knowing the exact concentrations, or even chemical forms, of biologically required elements is essential, intercalibration is a very relevant and needed tool. Implementing it is not simple because errors can occur at any step in the process of taking …

Phosphorus Cycling In The Sargasso Sea: Investigation Using The Oxygen Isotopic Composition Of Phosphate, Enzyme-Labeled Fluorescence, And Turnover Times, Karen Mclaughlin, Jill A. Sohm, Gregory A. Cutter, Michael W. Lomas, Adina Paytan

OES Faculty Publications

Dissolved inorganic phosphorus (DIP) concentrations in surface water of vast areas of the ocean are extremely low (<10 nM) and phosphorus (P) availability could limit primary productivity in these regions. We explore the use of oxygen isotopic signature of dissolved phosphate (δ¹⁸O_PO4) to investigate biogeochemical cycling of P in the Sargasso Sea, Atlantic Ocean. Additional techniques for studying P dynamics including ³³P-based DIP turnover time estimates and percent of cells expressing alkaline phosphatase (AP) activity as measured by enzyme-labeling fluorescence are also used. In surface waters, δ¹⁸O_PO4 values were lower than equilibrium by 3–6%, indicative of dissolved organic phosphorous (DOP) remineralization by extracellular enzymes. An isotope mass balance model using a variety of possible combinations of …

Using Ammonium Pore Water Profiles To Assess Stoichiometry Of Deep Remineralization Processes In Methanogenic Continental Margin Sediments, David J. Burdige, Tomoko Komada

OES Faculty Publications

In many continental margin Sediments, a deep reaction zone exists which is separated from remineralization processes near the sediment surface. Here, methane diffuses upward to a depth where it is oxidized by downwardly diffusing sulfate. However, the methane sources that drive this anaerobic oxidation of methane (AOM) in the sulfate-methane transition zone (SMT) may vary among sites. In particular, these sources can be thought of as either (i) "internal" sources from in situ methanogenesis (regardless of where it occurs in the sediment column) that are ultimately coupled to organic matter deposition and burial, or (ii) "external" sources such as hydrocarbon …

Diatom Proteomics Reveals Unique Acclimation Strategies To Mitigate Fe Limitation, Brook L. Nunn, Jessica F. Faux, Anna A. Hippman, Maria T. Maldonado, H. Rodger Harvey, David R. Goodlett, Philip W. Boyd, Robert F. Strzepek

OES Faculty Publications

Phytoplankton growth rates are limited by the supply of iron (Fe) in approximately one third of the open ocean, with major implications for carbon dioxide sequestration and carbon (C) biogeochemistry. To date, understanding how alteration of Fe supply changes phytoplankton physiology has focused on traditional metrics such as growth rate, elemental composition, and biophysical measurements such as photosynthetic competence (Fv/Fm). Researchers have subsequently employed transcriptomics to probe relationships between changes in Fe supply and phytoplankton physiology. Recently, studies have investigated longer-term (i.e. following acclimation) responses of phytoplankton to various Fe conditions. In the present study, the coastal diatom, Thalassiosira pseudonana, …

Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones

OES Faculty Publications

Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …

Isotopic (Δ13c, Δ14c) Analysis Of Organic Acids In Marine Samples Using Wet Chemical Oxidation, Susan Q. Lang, G. L. Früh-Green, S. M. Bernasconi, L. Wacker

Faculty Publications

We present a method for the isolation and off-line isotope analysis of formate and acetate in marine samples. Organic acids are separated by high performance liquid chromatography and collected in glass Exetainer® screw-capped vials that have been prespiked with an oxidant and flushed with helium. The vials are subsequently heated to convert the organic compounds to CO₂ for radiocarbon and δ¹³C analysis. Small aliquots are sampled for measurement of δ¹³C by isotope ratio mass spectrometry, whereas the majority of the CO₂ is saved for radiocarbon analysis by accelerator mass spectrometry using a gas ion …

Extreme Wave Events In Ireland: 14 680 Bp–2012, Laura Cooke, John M. Dudley, Frédéric Dias

Articles

The island of Ireland is battered by waves from all sides, most ferociously on the west coast as the first port of call for waves travelling across the Atlantic Ocean. However, when discussing ocean events relevant to the nation of Ire- land, one must actually consider its significantly larger designated continental shelf, which is one of the largest seabed territories in Europe. With this expanded definition, it is not surprising that Ireland has been subject to many oceanic events which could be designated as “extreme”; in this paper we present what we believe to be the first catalogue of such …

Conservation Mooring Study, Urban Harbors Institute, University Of Massachusetts Boston

Urban Harbors Institute Publications

Most boaters who moor their vessels in Massachusetts waters have traditionally employed free swinging moorings that use heavy bottom chain. In important sensitive habitats such as eelgrass beds, these types of moorings often have negative impacts on the benthic habitat – from the circular movement of the chain around the anchor point, and/or from the anchor itself.

This document objectively describes the different characteristics of conventional moorings versus conservation moorings designed to minimize disruption to the benthic habitat. This report includes discussions on the following topics:

• Technologies available
• Ecological impacts
• Functional differences
• Economical differences
• Regulatory issues

These comparisons, along with …

Contribution Of The Pacific Decadal Oscillation To Global Mean Sea Level Trends, B. D. Hamlington, R. R. Leben, M. W. Strassburg, R. S. Nerem, K-Y. Kim

CCPO Publications

Understanding and explaining the trend in global mean sea level (GMSL) have important implications for future projections of sea level rise. While measurements from satellite altimetry have provided accurate estimates of GMSL, the modern altimetry record has only now reached 20 years in length, making it difficult to assess the contribution of decadal to multidecadal climate signals to the global trend. Here, we use a sea level reconstruction to study the 20 year trends in sea level since 1950. In particular, we show that the Pacific Decadal Oscillation (PDO) contributes significantly to the 20 year trends in GMSL. We estimate …