Marine Biology Commons^™

Do Some Deep‐Sea, Sediment‐Dwelling Species Of Harpacticoid Copepods Have 1000‐Km‐Scale Range Sizes?, Erin E. Easton, David Thistle

School of Earth, Environmental, & Marine Sciences Faculty Publications

The range sizes of sediment‐dwelling deep‐sea species are largely unknown. Such knowledge is important because a deep sea composed in large part of species with 100‐km‐scale ranges would be very different from one composed predominantly of species with 1000‐km‐scale ranges. For example, the total species richness would be much greater in the first case than in the second. As a step towards the determination of the distribution of species’ range sizes in the deep sea, we asked whether harpacticoid copepods (Crustacea) on the continental rise in the northeastern Pacific had 1000‐km‐scale range sizes. We chose harpacticoids because they occur widely …

Potential And Timescales For Oxygen Depletion In Coastal Upwelling Systems: A Box-Model Analysis, Cheryl S. Harrison, B. Hales, S. Siedlecki, R. M. Samelson

School of Earth, Environmental, & Marine Sciences Faculty Publications

A simple box model is used to examine oxygen depletion in an idealized ocean-margin upwelling system. Near-bottom oxygen depletion is controlled by a competition between flushing with oxygenated offshore source waters and respiration of particulate organic matter produced near the surface and retained near the bottom. Upwelling-supplied nutrients are consumed in the surface box, and some surface particles sink to the bottom where they respire, consuming oxygen. Steady states characterize the potential for hypoxic near-bottom oxygen depletion; this potential is greatest for faster sinking rates, and largely independent of production timescales except in that faster production allows faster sinking. Timescales …

Systematic Patterning Of Sediments In French Polynesian Coral Reef Systems, Andrew Calhoun

HCNSO Student Theses and Dissertations

Through a discipline termed “comparative sedimentology”, modern carbonate depositional environments have been used extensively as analogs to aid in the interpretation of equivalent fossil systems. Using field samples, GIS and remote sensing data for three isolated carbonate platforms in the Pacific, this thesis seeks to examine relationships between grain texture and grain type and their environment of deposition. The motivation is to highlight relationships that have the potential to better understand facies relations on carbonate platforms, and thereby reduce uncertainty and increase accuracy of subsurface exploration. The results of this study show that on Raivavae, Tubuai, and Bora Bora: French …

Comparative Analysis Of Xenorhabdus Koppenhoeferi Gene Expression During Symbiotic Persistence In The Host Nematode, Ruisheng An, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Species of Xenorhabdus and Photorhabdus bacteria form mutualistic associations with Steinernema and Heterorhabditis nematodes, respectively and serve as model systems for studying microbe-animal symbioses. Here, we profiled gene expression of Xenorhabdus koppenhoeferi during their symbiotic persistence in the newly formed infective juveniles of the host nematode Steinernema scarabaei through the selective capture of transcribed sequences (SCOTS). The obtained gene expression profile was then compared with other nematode-bacteria partnerships represented by Steinernema carpocapsae-Xenorhabdus nematophila and Heterorhabditis bacteriophora-Photorhabdus temperata. A total of 29 distinct genes were identified to be up-regulated and 53 were down-regulated in X. koppenhoeferi while in S. scarabaei infective …

Marine Ecoregion And Deepwater Horizon Oil Spill Affect Recruitment And Population Structure Of A Salt Marsh Snail, Steven C. Pennings, Scott Zengel, Jacob Oehrig, Merryl Alber, T. Dale Bishop, Donald R. Deis, Donna Devlin, A. Randall Hughes, John J. Hutchens, Jr., Whitney M. Kiehn, Caroline R. Mcfarlin, Clay L. Montague, Sean P. Powers, C. Edward Proffitt, Nicholle Rutherford, Camille L. Stagg, Keith Walters

University Faculty and Staff Publications

Marine species with planktonic larvae often have high spatial and temporal variation in recruitment that leads to subsequent variation in the ecology of benthic adults. Using a combination of published and unpublished data, we compared the population structure of the salt marsh snail, Littoraria irrorata, between the South Atlantic Bight and the Gulf Coast of the United States to infer geographic differences in recruitment and to test the hypothesis that the Deepwater Horizon oil spill led to widespread recruitment failure of L. irrorata in Louisiana in 2010. Size-frequency distributions in both ecoregions were bimodal, with troughs in the distributions consistent …

Recent Increases In Arctic Freshwater Flux Affects Labrador Sea Convection And Atlantic Overturning Circulation, Qian Yang, Tim Dixon, Paul G. Myers, Jennifer Bonin, Don Chambers, M.R. Van Den Broeke, Mads H. Ribergaard, John Mortensen

School of Geosciences Faculty and Staff Publications

The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland’s ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from …

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 …

Beyond Just Sea-Level Rise: Considering Macroclimatic Drivers Within Coastal Wetland Vulnerability Assessments To Climate Change, Michael J. Osland, Nicholas M. Enwright, Richard H. Day, Christopher A. Gabler, Camille L. Stagg, James B. Grace

School of Earth, Environmental, & Marine Sciences Faculty Publications

Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate change-related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would …

Response Of Fishes To Restoration Projects In Bayou St. John Located Within The City Of New Orleans, Louisiana, Including Hydrological Characterization And Hydrodynamic Modelling, Patrick W. Smith

LSU New Orleans Theses and Dissertations

Quantifying the impacts of restoration on coastal waterways is crucial to understanding their effectiveness. Here, I look at the impacts of multiple restoration projects on urban waterways within the city limits of New Orleans, LA, with an emphasis on the response of fishes. First I report the effects of two projects designed to improve exchange down estuary on the hydrologic characteristics of Bayou St. John (BSJ). Within BSJ, flow is dominated by subtidal wind driven processes. Removal of an outdated flood control structure did not appear to alter exchange in BSJ, but removal combined with sector gate openings did. I …

Genomic And Transcriptomic Evidence For Scavenging Of Diverse Organic Compounds By Widespread Deep-Sea Archaea, Meng Li, Brett J. Baker, Karthik Anantharaman, Sunit Jain, John A. Breier, Gregory J. Dick

School of Earth, Environmental, & Marine Sciences Faculty Publications

Microbial activity is one of the most important processes to mediate the flux of organic carbon from the ocean surface to the seafloor. However, little is known about the microorganisms that underpin this key step of the global carbon cycle in the deep oceans. Here we present genomic and transcriptomic evidence that five ubiquitous archaeal groups actively use proteins, carbohydrates, fatty acids and lipids as sources of carbon and energy at depths ranging from 800 to 4,950 m in hydrothermal vent plumes and pelagic background seawater across three different ocean basins. Genome-enabled metabolic reconstructions and gene expression patterns show that …

Using Fish Population Metrics To Compare The Effects Of Artificial Reef Density, Catheline Y. M. Froehlich, Richard Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1–190 culverts. Abundances of adults and species evenness of juvenile populations differed between …

Factors Affecting Terrigenous Sedimentation In Coastal Bays With Coral Reefs: Implications For Monitoring The Effectiveness Of Watershed Restoration, Whitney Sears

Theses

In the Caribbean, sedimentation has been identified as a serious threat to coral reef communities. Although land-based sediment delivery to coastal waters harboring coral reefs occurs under natural conditions, human activities in the watersheds above reefs increases the erosion and delivery of terrigenous sediment to the reefs. Delivery of terrigenous sediment into marine areas below developed watersheds affects sedimentation rates, alters the composition and texture of sediments that are suspended in the water column, and/or sediments that are deposited on the sea floor and on corals.

St. John, U.S. Virgin Islands is an ideal location to study the effects of …

Particle Dynamics In The Rising Plume At Piccard Hydrothermal Field, Mid-Cayman Rise, Margaret L. Estapa, John A. Breier, Chris R. German

School of Earth, Environmental, & Marine Sciences Faculty Publications

Processes active in rising hydrothermal plumes, such as precipitation, particle aggregation, and biological growth, affect particle size distributions and can exert important influences on the biogeochemical impact of submarine venting of iron to the oceans and their sediments. However, observations to date of particle size distribution within these systems are both limited and conflicting. In a novel buoyant hydrothermal plume study at the recently discovered high-temperature (3988C) Piccard Hydrothermal Field, Mid- Cayman Rise, we report optical measurements of particle size distributions (PSDs). We describe the plume PSD in terms of a simple, power-law model commonly used in studies of upper …

Haverstraw Bay Benthic Habitat Characterization, Robert M. Cerrato, Alison M. Flanagan, Roger D. Flood

School of Marine & Atmospheric Sciences Faculty Publications

High-resolution backscatter and bathymetric maps created by multibeam and sidescan sonar surveys were used to identify five different seafloor bottom types within Haverstraw Bay. Grab samples were collected within these areas to characterize sediment properties and macrofauna. Selected sampling locations were revisited and seafloor images were obtained with an HD underwater camera. Multivariate analysis was used to identify the most important factors explaining variations in community structure. Results indicated that categorical variables defining bottom types, grain size, and water depth can explain about 42% of community structure variation. In addition, shell length data collected for Rangia cuneata, an introduced …

Lateral Dispersal And Foraging Behavior Of Entomopathogenic Nematodes In The Absence And Presence Of Mobile And Non-Mobile Hosts, Harit K. Bal, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Entomopathogenic nematodes have been classified into cruisers (active searchers) and ambushers (sit and wait foragers). However, little is known about their dispersal and foraging behavior at population level in soil. We studied lateral dispersal of the ambush foraging Steinernema carpocapsae (ALL strain) and cruise foraging Heterorhabditis bacteriophora (GPS11 strain) from infected host cadavers in microcosms (0.05 m2) containing Wooster silt-loam soil (Oxyaquic fragiudalf) and vegetation in the presence or absence of non-mobile and mobile hosts. Results showed that the presence of a non-mobile host (Galleria mellonella larva in a wire mesh cage) enhanced H. bacteriophora dispersal for up …

The Impact Of Stegastes Planifrons On The Resurgence Of Acropora Cervicornis, Zebulon Martin

Undergraduate Distinction Papers

This study examines resurgent patches of Acropora cervicornis in the “Coral Gardens” back-reef area of Ambergris Caye, Belize. The goal of this study was to understand the carbonate budget and ecosystem dynamics of this successful reef, with an emphasis on the role of Stegastes planifrons (the herbivorous threespot damselfish), on the health of the coral. Benthic survey data from photo-quadrats along six transects were supplemented with counts of S. planifrons, their chimney scars, and sea urchin (Echinometra viridis) to assess their impact on the reef. The data indicate a positive correlation between the density of Stegastes …

Changes In Spatial Patterns Of Caragana Stenophylla Along A Climatic Drought Gradient On The Inner Mongolian Plateau, Li-Na Xie, Hong-Yu Guo, Christopher A. Gabler, Qing-Fang Li, Cheng-Cang Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, “nurse effects” of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophylla across semi-arid, arid, and intensively arid zones. Our results showed that patches of C. stenophylla populations shifted from a random to a clumped spatial pattern towards drier environments. Seed density and seedling survival rate of C. stenophylla decreased from the semi-arid zone to …

Microbial Iron Mats At The Mid-Atlantic Ridge And Evidence That Zetaproteobacteria May Be Restricted To Iron-Oxidizing Marine Systems, Jarrod J. Scott, John A. Breier, George W. Luther Iii, David Emerson

School of Earth, Environmental, & Marine Sciences Faculty Publications

Chemolithoautotrophic iron-oxidizing bacteria play an essential role in the global iron cycle. Thus far, the majority of marine iron-oxidizing bacteria have been identified as Zetaproteobacteria, a novel class within the phylum Proteobacteria. Marine iron-oxidizing microbial communities have been found associated with volcanically active seamounts, crustal spreading centers, and coastal waters. However, little is known about the presence and diversity of iron-oxidizing communities at hydrothermal systems along the slow crustal spreading center of the Mid-Atlantic Ridge. From October to November 2012, samples were collected from rust-colored mats at three well-known hydrothermal vent systems on the Mid-Atlantic Ridge (Rainbow, Trans-Atlantic Geotraverse, and …

Rapid Imbibition Of Water In Fractures Within Unsaturated Sedimentary Rock, Chu-Lin Cheng, E. Perfect, B. Donnelly, H. Z. Bilheux, A. S. Tremsin, L. D. Mckay, V. H. Distefano, J. C. Cai, L. J. Santodonato

School of Earth, Environmental, & Marine Sciences Faculty Publications

The spontaneous imbibition of water and other liquids into gas-filled fractures in variably-saturated porous media is important in a variety of engineering and geological contexts. However, surprisingly few studies have investigated this phenomenon. We present a theoretical framework for predicting the 1-dimensional movement of water into air-filled fractures within a porous medium based on early-time capillary dynamics and spreading over the rough surfaces of fracture faces. The theory permits estimation of sorptivity values for the matrix and fracture zone, as well as a dispersion parameter which quantifies the extent of spreading of the wetting front. Quantitative data on spontaneous imbibition …

Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken

OES Faculty Publications

The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …

Empirical Modelling Of Solid-Blocking Effect In A Blazka Respirometer For Gag, A Large Demersal Reef Fish, Richard J. Kline, Daryl C. Parkyn, Debra J. Murie

School of Earth, Environmental, & Marine Sciences Faculty Publications

The effect of solid-body blocking in a large (257 l) Blazka-style respirometer was examined in gag Mycteroperca microlepis. Gag ranging from 376-690 mm total length were tested at velocities from 10 to 91 cm s-1 . The solid blocking effect (SBE) due to fish size, swimming speed, and water temperature was investigated by direct measurement of flow velocity at the area of the fish’s maximum girth as compared to measurements at the rear (center) of the swimming chamber. Three models were compared as corrections for the SBE: the standard Bell and Terhune (BT), a novel modification of the Bell and …

Octocoral Mitochondrial Genomes Provide Insights Into The Phylogenetic History Of Gene Order Rearrangements, Order Reversals, And Cnidarian Phylogenetics, Diego F. Figueroa, Amy R. Baco

School of Earth, Environmental, & Marine Sciences Faculty Publications

We use full mitochondrial genomes to test the robustness of the phylogeny of the Octocorallia, to determine the evolutionary pathway for the five known mitochondrial gene rearrangements in octocorals, and to test the suitability of using mitochondrial genomes for higher taxonomic-level phylogenetic reconstructions. Our phylogeny supports three major divisions within the Octocorallia and show that Paragorgiidae is paraphyletic, with Sibogagorgia forming a sister branch to the Coralliidae. Furthermore, Sibogagorgia cauliflora has what is presumed to be the ancestral gene order in octocorals, but the presence of a pair of inverted repeat sequences suggest that this gene order was not conserved …

Aptian To Santonian Foraminiferal Biostratigraphy And Paleoenvironmental Change In The Sverdrup Basin As Revealed At Glacier Fiord, Axel Heiberg Island, Canadian Arctic Archipelago, Claudia J. Schröder-Adams, Jens O. Herrle, Ashton F. Embry, James W. Haggart, Jennifer M. Galloway, Adam T. Pugh, David M. Harwood

ANDRILL Research and Publications

Exceptional exposures of a High Arctic Cretaceous sedimentary record were studied at Glacier Fiord, Axel Heiberg Island. The succession reveals a complex Aptian to Santonian paleoenvironmental history of the Sverdrup Basin that documents several global events. Foraminiferal faunas in combination with rare macrofossil occurrences permit the distinction of nine zones that facilitate biostratigraphic correlations to other High Arctic locales, the Beaufort Mackenzie Basin and the Western Interior Sea. The depositional environment as exposed in the Christopher, Hassel, Bastion Ridge and Kanguk formations changed frequently from a shelf to a shoreface setting. Most sequence boundaries appear to be conformable where shoaling …

Iron Sources And Dissolved-Particulate Interactions In The Seawater Of The Western Equatorial Pacific, Iron Isotope Perspectives, M. Labatut, F. Lacan, C. Pradoux, J. Chmeleff, A. Radic, J. W. Murray, F. Poitrasson, Anne M. Johansen, F. Thil

All Faculty Scholarship for the College of the Sciences

This work presents iron isotope data in the western equatorial Pacific. Marine aerosols and top core margin sediments display a slightly heavy Fe isotopic composition (δ⁵⁶Fe) of 0.33 ± 0.11‰ (2SD) and 0.14 ± 0.07‰, respectively. Samples reflecting the influence of Papua New Guinea runoff (Sepik River and Rabaul volcano water) are characterized by crustal values. In seawater, Fe is mainly supplied in the particulate form and is found with a δ⁵⁶Fe between −0.49 and 0.34 ± 0.07‰. The particulate Fe seems to be brought mainly by runoff and transported across continental shelves and slopes. …

First Record Of The Tropical House Gecko Hemidactylus Mabouia (Moreau De Jonnès, 1818) In Texas, Alejandro Fierro-Cabo, August Rentfro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Invasions of the tropical house gecko Hemidactylus mabouia (Moreau de Jonnes, 1818) in the tropical Americas are well documented. While this gecko has been reported as well established and expanding its range in Florida, here we document the first record in the United States outside of this state. We detected a small reproducing population in Cameron County, Brownsville, Texas. We expect a rapid colonization of buildings by this species in southern Texas. We consider that this potential invasion poses novel obstacles to the continued presence of the earlier invasive Mediterranean gecko Hemidactylus turcicus (Linnaeus, 1758) across Texas

Water Water Everywhere: Analyzing Long Island's Water Issues And Finding Solutions For A Sustainable Future, Anthony T. Becker

2014 Student Theses

Over three million people call Long Island their home. With access to beautiful landscapes, world-renowned beaches, and proximity to New York City, it is no wonder that so many proudly call this geographic stretch of glacial till their home. However, throughout the years our actions do not necessarily reflect this affection we have to our home. Years of sprawl and human infestation across the island have resulted in widespread environmental degradation. Specifically, the water we drink and the beaches we enjoy have become endangered. I plan on studying the urban ecology of how intensified population growth led to the eutrophication …

Restoration Of Tryptophan Hydroxylase Functions And Serotonin Content In The Atlantic Croaker Hypothalamus By Antioxidant Treatment During Hypoxic Stress, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

Antioxidants are prototypical scavengers of oxygen-free radicals and have been shown to prevent neuroendocrine dysfunction in vertebrates during oxidative stress. In the present study, we investigated whether antioxidant treatment can reverse hypoxia-induced down-regulation of hypothalamic tryptophan hydroxylase (TPH) and serotonergic functions in Atlantic croaker. Hypothalamic neuronal contents of TPH-1 and TPH-2 proteins, serotonin (5-hydroxytryptamine, 5-HT) and its precursor, 5-hydroxytryptophan (5-HTP) as well as hypothalamic TPH-1 and TPH-2 mRNA expression and TPH activity were measured in croaker after exposure to hypoxia and treatment with pharmacological agents. Multiple injections of N-ethylmaleimide, a sulfhydryl alkylating agent, caused comparable decreases in hypothalamic TPHs functions …

Growth And Nitrogen Uptake Kinetics In Cultured Procentrum Donghaiense, Zhangxi Hu, Shunshan Duan, Margaret R. Mulholland

OES Faculty Publications

We compared growth kinetics of Prorocentrum donghaiense cultures on different nitrogen (N) compounds including nitrate, ammonium urea, glutamic acid, dialanine, and cynate. P. donghaiense exhibited standard Monod-type growth kinetics over a range of nitrogen concentrations for all N. Compounds tested. Cultures grown on glu and urea had the highest maximum growth rates. However, cultures grown on cyanate had lower half saturation constants. Nitrogen uptake kinetics were measured in nitrate-deplete and replete batch cultures of P. donghaiense. In nitrate-deplete batch cultures, P. donghaiense exhibited Michaelis-Menten type uptake kinetics for nitrate, ammonium, urea and algal amino acids; uptake was saturated at …

Influence Of Constant And Periodic Experimental Hypoxic Stress On Atlantic Croaker Otolith Chemistry, John Mohan, Md. Saydur Rahman, Peter Thomas, Benjamin Walther

School of Earth, Environmental, & Marine Sciences Faculty Publications

The chemical composition of fish otoliths may provide information on the environmental exposure histories of fishes if ‘vital effects’ on element incorporation are minimal. In order to use redox-sensitive geochemical proxies, such as manganese, in otoliths to quantify sublethal exposure to hypoxia, the relative influence of endogenous and exogenous controls on otolith composition must first be validated. Controlled laboratory experiments were conducted on Atlantic croaker Micropogonias undulatus to examine the response of otolith Sr:Ca, Ba:Ca, Mg:Ca, Mn:Ca, and Na:Ca ratios to either constant or periodic hypoxia treatments for 4 and 10 wk, respectively. Although fish somatic growth and condition were …

Rapid Fluctuations In Mid-Latitude Siliceous Plankton Production During The Middle Eocene Climatic Optimum (Odp Site 1051, Western North Atlantic), Jakub Witkowski, Steven M. Bohaty, Kirsty M. Edgar, David M. Harwood

ANDRILL Research and Publications

The Middle Eocene Climatic Optimum (MECO; ~ 40 million years ago [Ma]) is one of the most prominent transient global warming events in the Paleogene. Although the event is well documented in geochemical and isotopic proxy records at many locations, the marine biotic response to the MECO remains poorly constrained. We present new high-resolution, quantitative records of siliceous microplankton assemblages from the MECO interval of Ocean Drilling Program (ODP) Site 1051 in the subtropical western North Atlantic Ocean, which are interpreted in the context of published foraminiferal and bulk carbonate stable isotope (δ¹⁸O and δ¹³C) records. …