Oceanography Commons^™

The Role Of Larval Dispersal In Metapopulation Gene Flow: Local Population Dynamics Matter, Daphne M. Munroe, John M. Klinck, Eileen E. Hofmann, Eric N. Powell

OES Faculty Publications

The degree of genetic connectivity among populations in a metapopulation has direct consequences for species evolution, development of disease resistance, and capacity of a metapopulation to adapt to climate change. This study used a metapopulation model that integrates population dynamics, dispersal, and genetics within an individual-based model framework to examine the mechanisms and dynamics of genetic connectivity within a metapopulation. The model was parameterized to simulate four populations of oysters (Crassostrea virginica) from Delaware Bay on the mid-Atlantic coast of the United States. Differences among the four populations include a strong spatial gradient in mortality, a spatial gradient …

Novel Lineages Of Prochlorococcus And Synechococcus In The Global Oceans, Sijun Huang, Steven W. Wilhelm, H. Rodger Harvey, Karen Taylor, Nianzhi Jiao, Feng Chen

OES Faculty Publications

Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and …

Diversity, Distribution, And Expression Of Diazotroph Nifh Genes In Oxygen-Deficient Waters Of The Arabian Sea, Amal Jayakumar, Mamoon M. D. Al-Rshadat, Bess B. Ward, Margaret R. Mulholland

OES Faculty Publications

The Arabian Sea oxygen minimum zone (OMZ), the largest suboxic region in the world's oceans, is responsible for up to half of the global mesopelagic fixed nitrogen ( N ) loss from the ocean via denitrification and anammox. Dinitrogen (N₂) fixation is usually attributed to cyanobacteria in the surface ocean. Model prediction and physiological inhibition of N₂ fixation by oxygen, however, suggest that N₂ fixation should be enhanced near the oxygen-deficient zone (ODZ) of the Arabian Sea. N₂ fixation and cyanobacterial nifH genes (the gene encoding dinitrogenase reductase) have been reported in surface waters overlying …

Database Of Diazotrophs In Global Ocean: Abundance, Biomass, And Nitrogen Fixation Rates, Y. W. Luo, S. C. Doney, L. A. Anderson, M. Benavides, I. Berman-Frank, A. Bode, S. Bonnet, K. H. Boström, D. Böttjer, D. G. Capone, M. R. Mulholland

OES Faculty Publications

Marine N₂ fixing microorganisms, termed di-azotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N₂) to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic cell counts or …

Circulation And Water Properties And Their Relationship To The Oyster Disease Msx In Delaware Bay, Zhiren Wang, Dale B. Haidvogel, David Bushek, Susan E. Ford, Eileen E. Hofmann, Eric N. Powell, John Wilkin

CCPO Publications

We apply a high-resolution hydro-dynamical model to investigate the role of physical factors influencing infection prevalence of Haplosporidium nelsoni, causative agent of MSX disease in the eastern oyster (Crassostrea virginica), in Delaware Bay, USA. Validation studies conducted for the years 2000 and 2010-2011 confirm that the model, based upon the Regional Ocean Modeling System, has significant skill in the recovery of observed water level, temperature, salinity, and velocity. Multi-year simulations are performed for periods representing temporal and spatial variations in H. nelsoni infection prevalence (1974-76, 1979-81, 1984-86, 1990-92, and 2006-09) to assess the degree to which the …

The Rise And Fall Of Crassostrea Virginica Oyster Reefs: The Role Of Disease And Fishing In Their Demise And A Vignette On Their Management, Eric N. Powell, John M. Klinck, Kathryn Ashton-Alcox, Eileen E. Hofmann, Jason Morson

CCPO Publications

We describe a model designed to simulate the shell carbonate budget of an oyster reef.We identify five parameters descriptive of basic characteristics of the shell carbonate budget of a reef that limit simulation accuracy. Two describe the TAZ (taphonomically-active zone) and the distribution of shell carbonate within it. One is the taphonomic rate in the TAZ. Two determine the volume contribution of shell carbonate and the taphonomic loss rate within the reef framework. For Mid-Atlantic estuaries, model simulations suggest that reef accretion only occurs if oyster abundance is near carrying capacity. Simulations further suggest that reef accretion is infeasible for …

Circulation And Behavior Controls On Dispersal Of Eastern Oyster (Crassostrea Virginica) Larvae In Delaware Bay, Diego A. Narvaez, John M. Klinck, Eric N. Powell, Eileen E. Hofmann, John Wilkin, Dale B. Haidvogel

CCPO Publications

The degree of genetic connectivity among populations in a metapopulation has direct consequences for species evolution, development of disease resistance, and capacity of a metapopulation to adapt to climate change. This study used a metapopulation model that integrates population dynamics, dispersal, and genetics within an individual-based model framework to examine the mechanisms and dynamics of genetic connectivity within a metapopulation. The model was parameterized to simulate four populations of oysters (Crassostrea virginica) from Delaware Bay on the mid-Atlantic coast of the United States. Differences among the four populations include a strong spatial gradient in mortality, a spatial gradient …

Modeling The Dispersal Of Eastern Oyster (Crassostrea Virginica) Larvae In Delaware Bay, Diego A. Narvaez, John M. Klinck, Eric N. Powell, Eileen E. Hofmann, John Wilkin, Dale B. Haidvogel

CCPO Publications

The interactions of circulation and growth processes in determining the horizontal distribution of eastern oyster (Crassostrea virginica) larvae in the Delaware Bay estuary were investigated with a coupled circulation-individual-based larvae model that used environmental conditions from the spawning seasons (mid-June to mid-September) of 1984, 1985, 1986, 2000, and 2001. Particles, representing oyster larvae, were released at five-day intervals from areas in Delaware Bay that correspond to natural oyster reefs. The simulated larval development time was used to estimate potential larval success, determined by the percent of larvae that successfully reached settlement size (330 µm) within the planktonic larval …

Can Oysters Crassostrea Virginica Develop Resistance To Dermo Disease In The Field: The Impediment Posed By Climate Cycles, Eric N. Powell, John M. Klinck, Ximing Guo, Eileen E. Hofmann, Susan E. Ford, David Bushek

CCPO Publications

Populations of eastern oysters, Crassostrea virginica, are commonly limited by mortality from dermo disease. Little development of resistance to Perkinsus marinus, the dermo pathogen, has occurred, despite the high mortality rates and frequency of epizootics. Can the tendency of the parasite to exhibit cyclic epizootics limit the oyster's response to the disease despite the presence of alleles apparently conferring disease resistance? We utilize a gene-based population dynamics model to simulate the development of disease resistance in Crassostrea virginica populations exposed to cyclic mortality encompassing periodicities expected of dermo disease over the geographic range at which epizootics have been …

Does Large-Scale Ocean Circulation Structure Life History Connectivity In Antarctic Toothfish (Dissostichus Mawsoni)?, Julian Ashford, Michael S. Dinniman, Cassandra Brooks, Allen H. Andrews, Eileen E. Hofmann, Gregor Cailliet, Christopher Jones, Nakul Ramanna

CCPO Publications

A multidisciplinary approach incorporating otolith chemistry, age data, and numerical Lagrangian particle simulations indicated a single, self-recruiting population of Antarctic toothfish (Dissostichus mawsoni) in the Southeast Pacific Basin (SPB) and Ross Sea, with a life history structured by the large-scale circulation. Chemistry deposited prior to capture along otolith edges demonstrated strong environmental heterogeneity, yet the chemistry in otolith nuclei, deposited during early life, showed no differences. Age data showed only adult fish in catches on the Pacific-Antarctic Ridge in the SPB and structuring of life stages consistent with transport pathways from the northern Ross Sea. Lagrangian particle simulations …

Patterns Of Extinction Risk And Threat For Marine Vertebrates And Habitat-Forming Species In The Tropical Eastern Pacific, Beth A. Polidoro, T. Brooks, Kent E. Carpenter, G. J. Edgar, S Henderson, J. Sanciangco, D. R. Robertson

Biological Sciences Faculty Publications

Marine conservation activities around the globe are largely undertaken in the absence of comprehensive species-specific information. To address this gap, complete regional species assemblages of major marine taxa are being progressively assessed against the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The present study is the first analysis of entire major components of the biota of a large marine biogeographic region conducted in the Tropical Eastern Pacific (TEP). It is based on recently completed IUCN Red List assessments for all known species of bony and cartilaginous shorefishes, corals, mangroves, …

Fall 2012, Nsu Oceanographic Center

Currents

No abstract provided.

Lesson Not Learned: Deepwater Horizon Research And Media Coverage Exposes Gaps In Knowledge And Risky Protocol Within The Oil Industry, Lauren Haller

Honors Theses

An insatiable thirst for oil has led poorly coordinated, risk-prone megasystems deeper into the ocean in search of new oil reserves. Profit-driven agendas at the corporate level have a top-down effect within these megasystems. Cost-cutting and risk-downplaying leaves the field employees unprepared to handle emergencies. A series of costly mistakes led to the 2010 BP Deepwater Horizon oil spill, which caused extensive damage to an already fragile ecosystem in the Gulf of Mexico. The wealth and political influence of the oil industry overpowers lax regulatory agencies and legislation-even though media and research has exposed frustrating parallels between the Deepwater Horizon …

Environmental Influences On Juvenile Fish Abundances In A River-Dominated Coastal System, Laure Carassou, Brian Dzwonkowski, Frank J. Hernandez, Jr., Sean P. Powers, William M. Graham, Kyeong Park, John Mareska

University Faculty and Staff Publications

We investigated the influence of climatic and environmental factors on variations in juvenile abundances of marine fishes in a river-dominated coastal system of the north-central Gulf of Mexico, where an elevated primary productivity sustains fisheries of high economic importance. Fish were collected monthly with an otter trawl at three stations near Mobile Bay from 1982 to 2007. Fish sizes were used to isolate juvenile stages within the data set, and monthly patterns in juvenile fish abundance and size were then used to identify seasonal peaks for each species. The average numbers of juvenile fish collected during these seasonal peaks in …

Circulation Of The Western Antarctic Peninsula: Implications For Biological Production, Maria Andrea Piñones Valenzuela

OES Theses and Dissertations

The western Antarctic Peninsula (wAP) continental shelf is characterized by large persistent populations of Antarctic krill ( Enphausia superba) and by regions of enhanced concentrations of marine mammals and other predators (hot spots). This study focused on understanding the role of ocean circulation in providing retention/connectivity of wAP Antarctic krill populations and in maintaining biological hot spot regions. Numerical Lagrangian particle tracking simulations obtained from the Regional Ocean Modeling System (ROMS) configured for the wAP region provided quantitative estimates of retention, immigration and emigration from the wAP continental shelf. Additional simulations with a one-dimensional temperature-dependent growth model for krill …

Rumbling In The Benthos: Acoustic Ecology Of The California Mantis Shrimp Hemisquilla Californiensis, E. Staaterman, C. Clark, A. Gallagher, M. Devries, T. Claverie, S. Patek

Faculty Publications, Biological Sciences

Although much research has focused on acoustic mapping and exploration of the benthic environment, little is known about the acoustic ecology of benthic organisms, particularly benthic crustaceans. Through the use of a coupled audio–video system, a hydrophone array, and an autonomous recording unit, we tested several hypotheses about the field acoustics of a benthic marine crustacean, Hemisquilla califor­niensis. Living in muddy burrows in southern California, these large mantis shrimp produce low frequency ‘rumbles’ through muscle vibrations. First, we tested whether acoustic signals are similar in the field and in the laboratory, and discovered that field-produced rumbles are more acoustically and …

Controls On The Formation Of Algal Blooms In The Lower Chesapeake Bay And Its Tributaries, Ryan Eric Morse

OES Theses and Dissertations

Algal blooms occur seasonally in the Chesapeake Bay and its tributaries, and while the consequences of algal blooms have been qualitatively and quantitatively assessed, the causes of algal blooms and mechanisms of bloom initiation are still not well understood despite decades of research. In order to understand nutrient dynamics and other factors that promote the initiation of algal blooms, the Lafayette River, a tidal sub-estuary of Chesapeake Bay that experiences seasonal algal blooms, was sampled daily in the fall of 2005. Three phytoplankton blooms (Chlorophyll a concentrations exceeding twice the average of monthly measurements from 2000-2009) occurred during this period, …

Super-Aggregations Of Krill And Humpback Whales In Wilhelmina Bay, Antarctic Peninsula, Douglas P. Nowacek, Ari S. Friedlaender, Patrick N. Halpin, Elliott L. Hazen, David W. Johnston, Andrew J. Read, Boris Espinasse, Meng Zhou, Yiwu Zhu

Environmental, Earth, and Ocean Sciences Faculty Publication Series

Ecological relationships of krill and whales have not been explored in the Western Antarctic Peninsula (WAP), and have only rarely been studied elsewhere in the Southern Ocean. In the austral autumn we observed an extremely high density (5.1 whales per km²) of humpback whales (Megaptera novaeangliae) feeding on a super-aggregation of Antarctic krill (Euphausia superba) in Wilhelmina Bay. The krill biomass was approximately 2 million tons, distributed over an area of 100 km² at densities of up to 2000 individuals m⁻³; reports of such ‘super-aggregations’ of krill have been absent in …

Population Dynamics Of Sheepshead (Archosargus Probatocephalus; Walbaum 1792) In The Chesapeake Bay Region: A Comparison To Other Areas And An Assessment Of Their Current Status, Joseph Charles Ballenger

OES Theses and Dissertations

Sheepshead recently have seen an increase in fishing pressure in Virginian waters of the Chesapeake Bay. This increase in fishing pressure has led to demands to install effective management measures to protect the fishery. However, no study regarding the population dynamics, and thus potential yield, of sheepshead has been conducted north of Cape Hatteras. We addressed the need for information regarding the population dynamics of Chesapeake Bay sheepshead by investigating their age distribution, growth rate and reproductive biology. We used this information to construct yield-per-recruit models, which local management agencies may use in the formation of scientifically based management measures. …

Summer 2011, Nova Southeastern University

Currents

No abstract provided.

Evaluating Methods For Optimizing Classification Success From Otolith Tracers For Spotted Seatrout (Cynoscion Nebulosus) In The Chesapeake Bay, Stacy Kavita Beharry

OES Theses and Dissertations

Identifying the natal sources of fish is an important step in understanding its population dynamics. Adult recruits are often sourced from multiple nursery areas, with good quality locations contributing disproportionately more fish to the adult stock. Because population persistence is strongly influenced by nursery habitat, methods that correctly identify the source of recruits are necessary for effective management. Within the last decade, otolith chemistry signatures have been increasingly used as a natural marker to delineate fish from a mixture of nursery sources. Despite the widespread use of otolith trace element and stable isotope ratios as habitat markers, the statistical approaches …

Use Of Sarima Models To Assess Data-Poor Fisheries: A Case Study With A Sciaenid Fishery Off Portugal, Nuno Prista, Norou Diawara, Maria J. Costa, Cynthia M. Jones

OES Faculty Publications

Research on assessment and monitoring methods has primarily focused on fisheries with long multivariate data sets. Less research exists on methods applicable to data-poor fisheries with univariate data sets with a small sample size. In this study, we examine the capabilities of seasonal autoregressive integrated moving average (SARIMA) models to fit, forecast, and monitor the landings of such data-poor fisheries. We use a European fishery on meagre (Sciaenidae: Argyrosomus regius), where only a short time series of landings was available to model (n=60 months), as our case-study. We show that despite the limited sample size, a SARIMA model could …

Anaerobic Oxidation Of Methane And The Stoichiometry Of Remineralization Processes In Continental Margin Sediments, David J. Burdige, Tomoko Kamada

OES Faculty Publications

In many coastal and continental margin sediments, pore-water property-property plots yield values of r_c:s, the stoichiometric ratio of dissolved inorganic carbon (DIC) produced to sulfate reduced, that are lower than the commonly assumed value of 2. Remineralization of organic matter more reduced than CH₂O can cause such observations, as can DIC loss due to authigenic carbonate precipitation. However, through studies of Santa Monica Basin sediments, we have observed that these observations could also be related to the occurrence of anaerobic oxidation of methane (AOM) in sediments. Specifically, using a reactive transport sediment model, we have shown …

Cascading Migrations And Implications For Vertical Fluxes In Pelagic Ecosystems, Stephen M. Bollens, Gretchen Rollwagen-Bollens, Joel A. Quenette, Alexander B. Bochdansky

OES Faculty Publications

Diel vertical migration is widespread across diverse taxa in the world's lakes and seas, yet its biogeochemical consequences are still poorly understood. The biologically mediated vertical flux of material in the ocean (also known as the "biological pump") is a matter of major interest and concern, as it is thought to play an important role in regulating ocean carbon storage, and by extension, the global carbon cycle. Recent studies spanning multiple trophic levels from fish to dinoflagellates have led us to a concept of coupled vertical migrations that we refer to as "cascading migrations". That is, migrations that …

Draft Genome Sequence Of Strain Himb100, A Cultured Representative Of The Sar116 Clade Of Marine Alphaproteobacteria, Jana Grote, Cansu Bayindirli, Kristin Bergauer, Paula C. De Moraes, Huan Chen, Lindsay D'Ambrosio, Bethany Edwards, Beatriz Fernandez-Gomez, Mariam Hamisi, Dan Nguyen, Yoshimi M. Rii, Emily Saeck, Charles Schutte, Brittany Widner

OES Faculty Publications

Strain HIMB100 is a planktonic marine bacterium in the class Alphaproteobacteria. This strain is of interest because it is one of the first known isolates from a globally ubiquitous clade of marine bacteria known as SAR116 within the family Rhodospirillaceae. Here we describe preliminary features of the organism, together with the draft genome sequence and annotation. This is the second genome sequence of a member of the SAR116 clade. The 2,458,945 bp genome contains 2,334 protein-coding and 42 RNA gene

Characterization Of Heterogeneities And Domains In Aquatic And Sedimentary Organic Matter By 1 H Spin Diffusion: Potential For Elucidating The Formation Mechanisms, Jingdong Mao, Xiaoyan Cao

Chemistry & Biochemistry Faculty Publications

Although the information on domains and heterogeneities of natural organic matter (NOM) can provide insights into its formation mechanisms, the appropriate solid-state NMR technique for measuring them is still lacking. The traditional technique requires mobility differences in NOM whereas NOM components are primarily rigid. We introduced a new ¹H spin diffusion technique, ¹H-¹³C two-dimensional heteronuclear correlation (2D HETCOR) NMR with ¹H spin diffusion, for characterization of domains and heterogeneities in aquatic and sedimentary organic matter. It was achieved by collecting a series of 2D HETCOR spectra with a variable mixing time, t_m', and …

Direct And Indirect Effects Of An Invasive Planktonic Predator On Pelagic Food Webs, Angela L. Strecker, Beatrix E. Beisner, Shelley E. Arnott, Andrew M. Paterson, Jennifer G. Winter, Ora E. Johannsson, Norman D. Yan

Environmental Science and Management Faculty Publications and Presentations

The relative importance of top-down invader effects relative to environmental drivers was determined by sampling crustacean zooplankton, rotifer, and phytoplankton communities in a set of invaded and noninvaded reference lakes. The non-native invertebrate predator Bythotrephes had significant effects on zooplankton community size structure, rotifers, and phytoplankton taxonomic composition, but no significant effects on crustacean zooplankton taxonomic and functional group composition. Part of the variation in phytoplankton communities was explained by the presence of the invader. Because Bythotrephes is generally known to be a carnivore and to not consume phytoplankton, this effect is likely mediated by the zooplankton community’s response to …

Spring 2011, Nsu Oceanographic Center

Currents

No abstract provided.

Global Patterns And Predictions Of Seafloor Biomass Using Random Forests, Chih-Lin Wei, Gilbert T. Rowe, Elva Escobar-Briones, Antje Boetius, Thomas Soltwedel, M. Julian Caley, Yousria Soliman, Falk Huettmann, Fangyuan Qu, Zishan Yu, C. Roland Pitcher, Richard L. Haedrich, Mary K. Wicksten, Michael A. Rex, Jeffrey G. Baguley, Jyotsna Sharma, Roberto Danovaro, Ian R. Macdonald, Clifton C. Nunnally, Jody W. Deming, Paul Montagna, Mélanie Lévesque, Jan Marcin Weslawski, Maria Wlodarska-Kowalczuk, Baban S. Ingole, Brian J. Bett, David S. M. Billett, Andrew Yool, Bodil A. Bluhm, Katrin Iken, Bhavani E. Narayanaswamy

Biology Faculty Publication Series

A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive …

A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves

Dissertations

This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty.

Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors …