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The Microbial Loop Concept: A History, 1930–1974, Peter J. Le B. Williams, Hugh W. Ducklow

Journal of Marine Research

The microbial loop as a leading concept in marine microbiology gained wide recognition in the 1980s, but it has roots extending back to the 1930s when microbiologists first began to take a more dynamic approach to investigating the roles of bacteria in ocean food webs and biogeochemical cycles. Here we present a history of the microbial loop concept with emphasis on the period starting in 1930, when marine bacteriologists in Russia and the West began to study explicitly the roles of marine bacteria in the sea. Selman Waksman at Woods Hole and Claude ZoBell at La Jolla relied on colony …

The Ecological And Biogeochemical State Of The North Pacifi C Subtropical Gyre Is Linked To Sea Surface Height, Benedetto Barone, Ashley R. Coenen, Stephen J. Beckett, Dennis J. Mcgillicuddy Jr., Joshua S. Weitz, David M. Karl

Journal of Marine Research

Sea surface height (SSH) is routinely measured from satellites and used to infer ocean currents, including eddies, that affect the distribution of organisms and substances in the ocean. SSH not only reflects the dynamics of the surface layer, but also is sensitive to the fluctuations of the main pycnocline; thus it is linked to events of nutrient upwelling. Beyond episodic upwelling events, it is not clear if and how SSH is linked to broader changes in the biogeochemical state of marine ecosystems. Our analysis of 23 years of satellite observations and biogeochemical measurements from the North Pacific Subtropical Gyre shows …

Bioaccumulation Of Heavy Metals In Mesozooplankton From A Human-Impacted South Western Atlantic Estuary (Argentina), Diana M. Villagran, Melisa D. Fernández Severini, Florencia Biancalana, Carla V. Spetter, Eleonora M. Fernández, Jorge E. Macrovecchio

Journal of Marine Research

The total metal concentrations (Cd, Cu, Pb, Zn, Mn, Ni, Cr, and Fe) in the mesozooplankton (200 μm–2 mm) were studied for a year in a human-impacted estuary strongly affected by urban and industrial discharges located in the South Atlantic. Over the last 25 years, this estuary has been the site of significant anthropogenic impacts including industrial activities, maritime traffic, and regular dredging. A quantitative and qualitative analysis was also carried out to identify the mesozooplanktonic community that was sampled for metal determinations. The mesozooplankton had high concentrations of toxic metals such as Cd, Pb, Cr, and Ni, which may …

Population Dynamics Of Pinfish In The Eastern Gulf Of Mexico (1998-2016), Meaghan E. Faletti, Dinorah H. Chacin, Jonathan A. Peake, Timothy C. Macdonald, Christopher D. Stallings

Marine Science Faculty Publications

Forage fishes play an important role in marine ecosystems by transferring energy and nutrients through the food web. The population dynamics of forage species can therefore have cascading effects across multiple trophic levels. Here, we analyzed a 19-year dataset on Pinfish (Lagodon rhomboides) across four eastern Gulf of Mexico estuaries to investigate population dynamics, inter- and intra-annual synchrony, metapopulation portfolio effects, growth, and habitat effects. Young-of-year growth rates did not differ among estuaries. The population dynamics of these four systems were stable in the long-term, but highly dynamic inter-annually. Intra-annual dynamics were stable and predictable despite variation in long-term means. …

Mass Spectrometry Analysis Of Contaminants Of Emerging Concern: Nanoparticles, Algal Toxins, And Cyanotoxins In Natural Waters And Their Potential Health Impacts, Ariel R. Donovan

Doctoral Dissertations

“The analysis of contaminants of emerging concern is critical to protecting environmental health. In the presented dissertation, two groups of contaminants of emerging concern were assessed using mass spectrometry methods: nanoparticles and algal and cyanotoxins.

Analysis of metal oxide nanoparticles in environmental matrices has been a challenging issue, as most traditional methods require complicated sample preparation methods or that can alter or destroy the nanoparticles in the system. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) methods were used to detect metal oxide nanoparticles in surface waters and their removal through drinking water treatment simulations while retaining all information regarding …

The Effects Of Kt ≠ Ks In A Stommel-Like Model Of The Upper Atlantic Meridional Overturning Circulation Under Steady Surface Flux Forcing, A. E. Gargett

Journal of Marine Research

This study examines a simple 6-box model of a single pole-to-pole ocean basin. Each of a northern "polar gyre," a southern "polar gyre," and an "equatorial gyre," consisting of north and south subtropical gyres plus the equatorial region, is represented by two boxes: a surface box receiving constant fluxes of both temperature (heat) and salt (freshwater) and a deep box. The model includes four dominant processes: surface flux forcing, horizontal meridional advection driven by Southern Ocean winds, horizontal eddy diffusion at gyre boundaries, and convection, as well as the process of vertical diffusion by small-scale processes. Provided that heat loss …

Amazon River Infl Uence On Nitrogen Fi Xation In The Western Tropical North Atlantic, Joseph P. Montoya, Jason P. Landrum, Sarah C. Weber

Journal of Marine Research

We measured rates of N- and C-fixation with a direct tracer method in regions of the western tropical North Atlantic influenced by the Amazon River plume during the high flow period of 2010 (May–June 2010). We found distinct regional variations in N-fixation activity, with the lowest rates in the plume proper and the highest rates in the plume margins and in offshore waters. A comparison of our N- and C-fixation measurements showed that the relative contribution of N-fixation to total primary production increased from the plume core toward oceanic waters, and that most of the C-fixation in this system was …

Ecophysiology Of Lionfish Metabolic And Visual Systems: Are There Physiological Limits To Inshore Invasion?, Aaron Hasenei

HCNSO Student Theses and Dissertations

Lionfish (Pterois spp.), an invasive species native to the Indo-Pacific, have permanently established themselves throughout the greater Caribbean, Gulf of Mexico, and regions of the Western Atlantic ranging from as far north as North Carolina to central Brazil. As their fundamental range expands, lionfish threaten to migrate into estuarine environments as they have been found to tolerate low salinities and an eclectic range of temperatures. The physiological capacity of invasion was assessed by quantifying the visual ecology of lionfish utilizing corneal electroretinography (ERG) as well as their metabolic scope and hypoxia tolerances under various temperature-oxygen-regimes utilizing intermittent-flow respirometry. Seasonal …

Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham

Dissertations, Theses, and Capstone Projects

Coastal megacities deposit significant amounts of carbon (C), nitrogen (N) and other pollutants into surrounding waters. These inputs, including wastewater and surface water runoff, may affect estuarine and adjacent wetland biogeochemical cycles, microbial production and ultimately greenhouse gas (GHG) efflux. In many megacities pollutant loading is typically greatest after periods of precipitation when the volume of wastewater and storm water runoff exceeds local sanitation capacity, resulting in the discharge of raw sewage into adjacent waters. These combined sewage overflow (CSO) events have received considerable attention primarily due to their potential impact on human health and eutrophication. However, whether these events …

Molecular Ecology And Management Of Nuisance And Invasive Marine Species : Chrysaora Chesapeakei, Moerisia Sp., And Gonionemus Vertens, Dena J. Restaino

Theses, Dissertations and Culminating Projects

Ecological communities are under constant pressure from anthropogenic disturbances. Marine and estuarine systems are affected by human use and development of both coastal land and the surrounding water. One consequence of this use is the deterioration of water quality, which can lead to changes in community structure and a loss of species richness. Another effect of increased usage of marine water ways in the introduction of invasive species. These non-natives also have the ability to change community structure and reduce ecosystem services. In particular cnidarians are able to thrive in degraded systems in part owing to their ability to tolerate …

Effects Of Drift Macroalgae On Sediment Nitrogen Cycling In Thalassia Testudinum Beds Of St. Joseph Bay, Fl, Erica Strope

Master of Science in Integrative Biology Theses

Anthropogenic nitrogen (N) loading and eutrophication can affect valuable ecosystem services and seagrass habitats by modifying structural and functional aspects of estuarine communities including increasing and prolonging macroalgae blooms. In some contexts, macroalgae may play a key role in N cycling pathways because they can alter sediment chemistry. Previous research has associated drift macroalgae blooms with elevated dissolved inorganic N concentrations in sediments as a result of increased remineralization of organic matter, but drift macroalgae effects on microbial N transformation pathways are not well understood. This study quantified the effects of macroalgae on estuarine N cycling in Thalassia testudinum seagrass …

Carbon Budget Of Tidal Wetlands, Estuaries, And Shelf Waters Of Eastern North America, R. G. Najjar, M. Herrmann, R. Alexander, D. J. Burdige, D. Butman, W.-J. Cai, E. A. Canuel, R. F. Chen, M. A. M. Friedrichs, M. R. Mulholland

OES Faculty Publications

Carbon cycling in the coastal zone affects global carbon budgets and is critical for understanding the urgent issues of hypoxia, acidification, and tidal wetland loss. However, there are no regional carbon budgets spanning the three main ecosystems in coastal waters: tidal wetlands, estuaries, and shelf waters. Here we construct such a budget for eastern North America using historical data, empirical models, remote sensing algorithms, and process‐based models. Considering the net fluxes of total carbon at the domain boundaries, 59 ± 12% (± 2 standard errors) of the carbon entering is from rivers and 41 ± 12% is from the atmosphere, …

Rectified Flow In A Stratified Coastal Ocean, K. H. Brink

Journal of Marine Research

An idealized numerical model is used to explore the generation of mean flows by oscillating wind forcing in a stratified coastal ocean with no alongshore variability, i.e., where neither barotropic nor baroclinic instability is a factor. On the inner shelf, where surface-to-bottom mixing occurs, a mean cross-shelf flow develops, as examined by Castelao et al. (2010), and the present results suggest that this flow can remain two-dimensional if there is a nonzero cross-shelf density gradient. Offshore of the inner shelf, where the water column is stratified, a mean alongshore flow develops in the direction opposite to coastal-trapped wave propagation. This …

Antarctic Mode Water, K. Speer, J.-B. Sallee, V. Pellichero

Journal of Marine Research

An estimate of Southern Ocean volume in temperature-salinity (T-S) classes is made with a focus on cold water masses south of the Polar Front, at depths shallower than 2,000 m. The volumetric diagram for waters below 5^° C shows a deficit at temperatures near 0^° C and 34.2 psu, surrounded by a ring of larger volumes, related to water mass formation near the Polar Front and near the continental margins as well as mixing effects. The cold, fresh extreme of the Antarctic Intermediate Water T-S relation shows a volumetric maximum, apparently distinct from the interior T-S relationship. We …

Multi-Decadal Trends And Variability In Temperature And Salinity In The Mid-Atlantic Bight, Georges Bank, And Gulf Of Maine, Elizabeth J. Wallace, Lev B. Looney, Donglai Gong

Journal of Marine Research

Increasing attention is being placed on the regional impact of climate change. This study focuses on the decadal scale variabilities of temperature and salinity in the Mid-Atlantic Bight (MAB), Georges Bank (GB), and Gulf of Maine (GOM) from 1977 to 2016 using hydrographic survey data from the National Oceanic and Atmospheric Administration (NOAA) Northeast Fisheries Science Center. The MAB (as defined by the shelf regions from Cape Hatteras to Cape Cod) experienced warming rates of 0.57 °C per decade during the Winter/Spring season (Jan–Apr) and 0.47 °C per decade during the Fall/Winter season (Sep–Dec). The GOM and GB, on the …

Chemical And Phycological Structure Of Surface Microlayer And Subsurface Water In A Southern Baltic Sea Estuary, Józef Piotr Antonowicz, Anna Kozak

Journal of Marine Research

The surface microlayer of water (SML) is a unique ecotone found on all water bodies. It is an interphase for the exchange of matter between the hydrosphere and the atmosphere. This ecotone is capable of accumulating chemicals and microorganisms in amounts as high as 100-fold greater than those observed in the pelagic zone. Here we report on the accumulation of chemicals and phytoneuston in the SML of the estuarial Łebsko Lake located at the southern coast of the Baltic Sea in the unpolluted region of the World Biosphere Reserve: the Słowínski National Park in Poland. The physicochemical parameters and phytoplankton …

Lagrangian Dispersion Characteristics In The Western Mediterranean, Maher Bouzaiene, Milena Menna, Pierre-Marie Poulain, Dalila Elhmaidi

Journal of Marine Research

Dispersion characteristics in the Western Mediterranean are analyzed using data from Coastal Ocean Dynamics Experiment (CODE) and Surface Velocity Program (SVP) surface drifters deployed in the period 1986–2017. Results are presented in terms of absolute dispersion A² (mean-squared displacement of drifter individuals) and of relative dispersion (D²; mean square separation distance of drifter pairs). Moreover, the dispersion characteristics are estimated for different initial separation distances (D₀) between particles: smaller, larger, or comparable with the internal Rossby radius of deformation. Results show the presence of a quasiballistic regime for absolute dispersion at small time scales and …

Expected Limits On The Ocean Acidification Buffering Potential Of A Temperate Seagrass Meadow, David A. Koweek, R. C. Zimmerman, Kathryn M. Hewett, Brian Gaylord, Sarah N. Giddings, Kerry J. Nickols, Jennifer L. Ruesink, John J. Stachowicz, Yuichiro Takeshita, Ken Caldeira

OES Faculty Publications

Ocean acidification threatens many marine organisms, especially marine calcifiers. The only global‐scale solution to ocean acidification remains rapid reduction in CO₂ emissions. Nevertheless, interest in localized mitigation strategies has grown rapidly because of the recognized threat ocean acidification imposes on natural communities, including ones important to humans. Protection of seagrass meadows has been considered as a possible approach for localized mitigation of ocean acidification due to their large standing stocks of organic carbon and high productivity. Yet much work remains to constrain the magnitudes and timescales of potential buffering effects from seagrasses. We developed a biogeochemical box model to …

Why Is The Ocean Surface Slightly Warmer Than The Atmosphere?, Lakshika Girihagama, Doron Nof

Journal of Marine Research

How much warmer is the ocean surface than the atmosphere directly above it? The present study offers a means to quantify this temperature difference using a conceptual nonlinear one-dimensional global energy balance coupled ocean–atmosphere model ("Aqua Planet"). The significance of our idealized model, which is of intermediate complexity, is its ability to obtain an analytical solution for the global average temperatures. Our analytical model results show that, for the present climate, predicted global mean ocean temperature is 291.1 K whereas surface atmospheric temperature above the ocean surface is 287.4 K. Thus, the modeled surface ocean is 3.7 K …

High-Frequency Variability In The North Icelandic Jet, B. E. Harden, R. S. Pickart

Journal of Marine Research

We describe the high-frequency variability in the North Icelandic Jet (NIJ) on the Iceland Slope using data from the densely instrumented Kögur mooring array deployed upstream of the Denmark Strait sill from September 2011 to July 2012. Significant sub-8-day variability is ubiquitous in all moorings from the Iceland slope with a dominant period of 3.6 days. We attribute this variability to topographic Rossby waves on the Iceland slope with a wavelength of 62 ± 3 km and a phase velocity of 17.3 ± 0.8 km/day^–1 directed downslope (–9° relative to true-north). We test the theoretical dispersion relation for these …

Decomposition Of Black Mangrove (Avicennia Germinans ) Leaf Litter: Calibrating Estuarine Indicators Of Functional Recovery, Leticia Martinez Contreras

Theses and Dissertations

Decomposition of plant material produced by mangroves and other macrophytes in estuaries occurs in both sediments and the water column. Early and intense processing could be more common in the water. In a previous study, in situ decomposition rates of Black Mangrove (Avicennia germinans ) leaf litter suspended in the water column differed among three estuaries in south Texas with moderate differences in salinity, water temperature, available nitrogen (N), and tidal flow. A series of microcosm experiments were conducted to determine the influence, within observed ranges in the estuaries, of these water variables on mass loss of Black Mangrove …

Macrobenthos Community Succession In The Northern Gulf Of Mexico Hypoxic Regions: Testing The Pearson-Rosenberg Model, Shivakumar K. Shivarudrappa, Kevin B. Briggs

Journal of Marine Research

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen concentration ≤2 mg L^–1) on the macrobenthic community on the continental shelf of the northern Gulf of Mexico. The stress-response relationship between bottom-water oxygen concentration and the macrobenthic community was used to determine the ecological condition of the benthic habitat. In lieu of testing the effect of decreasing influence of organic enrichment on the macrobenthic community as a function of distance from the source of organic pollution, we tested the effect of bottom-water dissolved oxygen concentration as a …

The Sea: The Science Of Ocean Prediction, Nadia Pinardi, Pierre F. J. Lermusiaux, Kenneth H. Brink, Ruth H. Preller

Journal of Marine Research

At the beginning of the 20th century Vilhelm Bjerknes defined the “ultimate problem ofmeteorology and hydrography” as the discovery of “the laws according to which an atmospheric or hydrospheric state develops out of the preceding one” and the “precalculation of future states” from gridded analyzed observations—that is, forecasting. The development of the electronic computer and the vision of several meteorologists allowed the transformation of meteorology into a sophisticated scientific discipline based on physics and mathematics. The first successful meteorological forecast was carried out in the 1950s. Meteorological forecasting became an operational activity at the end of the 1960s. The contributions …

Some Considerations About Coastal Ocean Observing Systems, K. H. Brink, Anthony R. Kirincich

Journal of Marine Research

Coastal ocean observing capabilities are evolving rapidly, both in terms of sensors and in terms of the volume of information available. We discuss the aspects of the coastal ocean that make it a unique environment, both in terms of physical processes and measurement techniques. Although many global-level systems are relevant to the coastal ocean, we concentrate on treating systems that are unique to the continental shelf environment. Further, we briefly discuss examples of measurement systems that would be useful for developing and driving ocean prediction systems.

Langmuir Supercells On The Middle Shelf Of The South Atlantic Bight: 1. Cell Structure, D. K. Savidge, A. E. Gargett

Journal of Marine Research

Langmuir circulation cells extending through entire water columns exert a profound influence on sediment transport on shallow shelves, hence their designation as "Langmuir Supercells" (LSs) upon discovery in 2004 in water of 15 m depth at the Long-Term Ecosystem Observatory (LEO) off New Jersey (United States). Until now, similar high-frequency, full water column measurements of turbulent velocities and density fields have not been reported from significantly deeper continental shelf environments. Such deeper measurements are needed to determine whether LSs exist to influence sediment transport outside the inner shelf. In this article, that deficiency is addressed, using measurements from a midshelf …

A New Era For The Sea, K. H. Brink, James J. Mccarthy

Journal of Marine Research

Now in its 80th year of publication, Journal of Marine Research has always striven to serve the oceanographic community by publishing papers vital to the marine research in the long and rich tradition of the Sears Foundation for Marine Research. As such, with this special issue we bring into the fold The Sea, the long-standing highly respected series that provides a continuing, comprehensive, and timely synthesis of the state of knowledge of ocean science...

Rainfall Effect On Sediment And Nutrient Fluxes In A Small Mangrove River, Okinawa, Japan, Kazumi Terada, Yukio Koibuchi, Masahiko Isobe

Journal of Marine Research

To understand the effect of rainfall on sediment and nutrient fluxes in a mangrove river ecosystem, field observations were conducted in the Fukido River, Okinawa, Japan. Water currents and water quality parameters (salinity and turbidity) were measured at the river mouth and upstream, and surface water samples were analyzed for nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, SiO₂-Si, suspended solids [SS], total nitrogen [TN], and total phosphorus [TP]). Observations were conducted on both clear and rainy days, which revealed the effect of weather. SS flux at the river mouth (outflux to sea) and upstream …

Recent Advances In Nearshore Wave, Circulation, And Sediment Transport Modeling, James T. Kirby

Journal of Marine Research

Significant advances in the modeling of nearshore processes have occurred over recent decades as a result of developments in both computational approaches and theoretical understanding. This review examines the present state of progress primarily from a hydrodynamics standpoint, followed by a brief discussion of applications to sediment transport and morphological evolution. Wave-averaged formulations of the wave-current interaction problem and resulting models for wave-induced currents are reviewed in order to compare and contrast radiation stress and vortex force approaches. Waveresolving approaches are then discussed, with an emphasis on the recent rapid development of 3D nonhydrostatic models and their application to a …

Forecast Errors, Goodness, And Verification In Ocean Forecasting, Gary B. Brassington

Journal of Marine Research

Verification is an essential part of the forecast process that provides guidance on the statistical behavior of the system and a framework by which a forecast can be assessed for its "goodness." Much of the framework applicable to ocean forecasting has been developed within the atmospheric community. A review of the available material is given with some commentary on its relevance in the context of ocean forecasting. A statistical theory is presented for errors in an ocean forecast system (both deterministic and ensemble) and for a number of verification metrics. Theoretical results are demonstrated with empirical models and results from …

The Effect Of A Strong Warm Winter On Subtropical Zooplankton Biomass And Metabolism, Inma Herrera, José Lopéz-Cancio, Lidia Yebra, Santiago Hernández-Léon

Journal of Marine Research

Winter 2010 was the warmest of the last 30 years in the subtropical oceanic waters north of the Canary Islands. Sea surface temperature was always above 19°C, promoting a strong stratification and preventing the expected late winter bloom. The knowledge of how planktonic organisms respond to such a warm scenario is of paramount importance to predict the effect of future ocean changes. In this study, zooplankton biomass and gut fluorescence (GF), electron transport system (ETS) activity, and aminoacyl-tRNA synthetases (AARS) activity were measured as proxies of metabolism in the oceanic waters north of the Canary Islands during the winter–spring period …