Oceanography and Atmospheric Sciences and Meteorology Commons^™

Radiocarbon Evidence For The Importance Of Surface Vegetation On Fermentation And Methanogenesis In Contrasting Types Of Boreal Peatlands, J. P. Chanton, P. H. Glaser, L. S. Chasar, David J. Burdige, M. E. Hines, D. I. Seigel, L. B. Tremblay, W. T. Cooper

OES Faculty Publications

We found a consistent distribution pattern for radiocarbon in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and methane replicated across spatial and temporal scales in northern peatlands from Minnesota to Alaska. The ¹⁴C content of DOC is relatively modern throughout the peat column, to depths of 3 m. In sedge-dominated peatlands, the ¹⁴C contents of the products of respiration, CH₄ and DIC, are essentially the same and are similar to that of DOC. In Sphagnum- and woody plant-dominated peatlands with few sedges, however, the respiration products are similar but intermediate between the ¹⁴C contents of …

Co2 Sensitivity Of Southern Ocean Phytoplankton, Philippe D. Tortell, Christopher D. Payne, Yingyu Li, Scarlett Trimborn, Bjorn Rost, Walker O. Smith, Christina Riesselman, Robert B. Dunbar, Peter Sedwick, Giacomo R. Ditullio

OES Faculty Publications

The Southern Ocean exerts a strong impact on marine biogeochemical cycles and global air-sea CO₂ fluxes. Over the coming century, large increases in surface ocean CO₂ levels, combined with increased upper water column temps. and stratification, are expected to diminish Southern Ocean CO₂ uptake. These effects could be significantly modulated by concomitant CO₂-dependent changes in the region's biol. carbon pump. Here we show that CO₂ concentrations affect the physiology, growth and species composition. of phytoplankton assemblages in the Ross Sea, Antarctica. Field results from in situ sampling and ship-board incubation experiments demonstrate that inorganic …

The Use Of Extractable Lipofuscin For Age Determination Of Crustaceans: Reply To Sheehy (2008), H. Rodger Harvey, David H. Secor, Se-Jong Ju

OES Faculty Publications

The heterogeneous mixture of metabolic by-products termed lipofuscin (LF) or age pigments has long been known to accumulate in post mitotic cells with increasing age. In crustaceans several approaches have been developed over the years to track LF accumulation and provide a proxy for chronological age. Histological approaches have been traditionally used for LF determination of crustaceans (e.g. Sheehy et al. 1994, Mar Biol 121:237-245), but over the last decade extraction approaches for neural tissues have been introduced (Ju et al. 1999, Mar Ecol Prog Ser 185:171-179) and tested (Ju et al. 2001, Mar Ecol Prog Ser 224:197-205; 2003, Fish …

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO₂ levels. Rates of N₂ and CO₂ fixation and growth increased in step with increasing partial pressure of CO₂ (pCO₂), but only under Fe- replete conditions. N₂) and carbon fixation rates at 75 Pa CO₂ were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO_{2 …}

Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett

OES Faculty Publications

We used the radiated shanny Ulvaria subbifurcataas a model species to explore the relative gut fullness from hatch to metamorphosis of wild larvae, and compared these values with those of laboratory-reared larvae fed at maximum rates. Ingestion rates of most wild larvae were above starvation levels but below the maximum feeding levels of laboratory-reared larvae. Twenty-six percent of freshly-hatched wild larvae and 11% of large, pre-settlement wild larvae had insufficient food in their stomach to satisfy metabolic requirements. These results, taken on their own, are consistent with the much hypothesized increased foraging performance and survival of larger larvae relative …

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.

Naturally Present Fatty Acids As Internal Calibrants For Fourier Transform Mass Spectra Of Dissolved Organic Matter, Rachel L. Sleighter, Georgina A. Mckee, Zhanfei Liu, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The analysis of dissolved organic matter ( DOM) by Fourier transform ion cyclotron resonance mass spectrometry ( FTICR- MS) has gained wide interest recently, driven primarily by its ultrahigh resolving power and mass accuracy. Accurate calibration of mass spectra is a key step to successfully decipher the DOM components. We propose a simple and accurate method to internally calibrate the peaks in the complex spectra without the need to add a calibrant. Mass spectra of DOM samples from the Dismal Swamp, Virginia, and the lower Chesapeake Bay display the presence of naturally occurring fatty acids which can be readily recognized …

Behavior Of An Escolar Lepidocybium Flavobrunneum In The Windward Passage As Determined By Popup Satellite Archival Tagging, David Kerstetter, P. H. Rice, Derke Snodgrass, Eric Prince

Marine & Environmental Sciences Faculty Articles

In June 2003, fisheries research was conducted in the Windward Passage using a chartered commercial pelagic longline vessel (Rice and Snodgrass 2003). This paper describes the habitat use by an escolar in this location tagged with a pop-up satellite archival tag (PSAT) that remained attached to the fish for 14 d. Data recovered from the PSAT were used to directly document diel vertical migration and ambient temperature range for the first time in a mesopelagic teleost.

Salt Marshes As A Source Of Chromophoric Dissolved Organic Matter (Cdom) To Southern California Coastal Waters, Catherine D. Clark, Liannea P. Litz, Stanley B. Grant

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

To determine chromophoric dissolved organic matter (CDOM) sources in Southern California coastal waters, optical properties of a river outlet and adjacent tidally flushed salt marshes were monitored (dry season; June July 2001). Average absorption coefficients doubled at ebb vs. flood tides (4.8 +/- 1.5 vs. 2.1 +/- 0.9 m(-1); 300 nm), suggesting significant salt marsh CDOM inputs into coastal waters. Average spectral slopes were not statistically different for any sites or tides (0.010 +/- 0.002 nm(-1)), consistent with salt marsh CDOM dominating coastal waters. Three-dimensional fluorescence excitation-emission matrices (EEMs) at ebb tide showed contributions from terrestrial, protein, and marine humic-like …

Shading Facilitates Sessile Invertebrate Dominance In The Rocky Subtidal Gulf Of Maine, Ron J. Etter, Robert J. Miller

Biology Faculty Publication Series

Dramatic shifts in community composition occur between vertical and horizontal rocky surfaces in subtidal environments worldwide, yet the forces mediating this transition are poorly understood. Vertical rock walls are often covered by lush, diverse communities of sessile suspension-feeding invertebrates, while adjacent horizontal substrates are dominated by algae, or corals in the tropics. Multiple factors, including light, sedimentation, water flow, and predation have been proposed to explain this pattern, but experimental tests of these hypotheses are lacking. We manipulated light level and predation to test whether variation in these mechanisms could be responsible for the shift in composition of sessile communities …

A Modelling Study Of Developmental Stage And Environmental Variability Effects On Copepod Foraging, Jerry D. Wiggert, Eileen E. Hofmann, Gustav-Adolf Paffenhöfer

CCPO Publications

We used a stochastic Lagrangian model to study how behaviour contributes to copepod grazing success. The model simulates distinct foraging behaviours of Clausocalanus furcatus, Paracalanus aculeatus, and Oithona plumifera. Three sets of simulations were performed to investigate the effects of (a) prey-size preference; (b) variation in prey-size spectra; and (c) turbulence intensity on these species’ grazing rates. The size preference simulations demonstrate that, compared with copepodites, mature females have cell ingestion rates that are an order of magnitude lower, while carbon uptake is reduced by 35%. A prey spectrum that is skewed towards cells ,<6 >μm promotes copepodite …

Otolith Chemistry Indicates Population Structuring By The Antarctic Circumpolar Current, Julian R. Ashford, Cynthia M. Jones, Eileen E. Hofmann, Inigo Everson, Carlos A. Moreno, Guy Duhamel, Richard Williams

CCPO Publications

Large-scale transport of seawater in ocean currents may generate spatially complex population structure through the advection of life stages of marine fish species. To test this, we compared the chemistry of otolith nuclei from Patagonian toothfish (Dissostichus eleginoides), presently managed as spatially discrete Populations corresponding to fishing management areas along the Antarctic Circumpolar Current (ACC), which transports water eastward around the Southern Ocean. The chemistry of otolith nuclei, laid down during early life, differed significantly between fishing areas Off South America and the Antarctic and between some Antarctic areas. However, we found significant discrepancies from expectation for a …

Survival Of Eastern Oysters Crassostrea Virginica From Three Lines Following Experimental Challenge With Bacterial Pathogens, Javier Gomez-Leon, Luisa Villamil, Scott A. Salger, Rachel Sallum, Antonio Remacha-Trivino, Dale F. Leavitt, Marta Gomez-Chiarri

Fisheries, Animal and Veterinary Sciences Faculty Publications

Shellfish production is often affected by bacterial pathogens that cause high losses in hatcheries and nurseries. We evaluated the relative survival of larvae and juveniles of 3 Crassostrea virginica oyster lines: (1) GHP, a Rhode Island line; (2) NEHY, a line resistant to dermo and multinucleated sphere X diseases; and (3) FLOWERS, a line resistant to Roseovarius oyster disease, experimental challenge with Vibrio spp. isolates RE22 and RE101, causative agents of bacillary necrosis in Pacific oyster larvae, and the type strain of Roseovarius crassostreae, causative agent of Roseovarius oyster disease. All of the isolates were able to induce significant …

State Of The River Report For The Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, And Contaminants 2008, Environmental Protection Board, City Of Jacksonville, University Of North Florida, Jacksonville University

State of the River Report

No abstract provided.

Climate Change, Vulnerability And Adaptation For South-West Western Australia: Phase One Of Action 5.5, Western Australian Greenhouse Strategy, Luke Morgan, Jo Anne Molin, Ross George, Richard Mckellar, Janet Conte

Bulletins 4000 -

This report outlines preliminary findings about the impacts of climate changes that occurred during 1975 to 2005 on the South West’s people, its economy and natural ecosystems. The report focuses on vulnerability and adaptation, identifying useful pointers for future work, particularly in relation to how well the community, stakeholders and decision-makers understand climate change as an issue and a threat.

Setting Targets For Resource Condition In Narrakine Gully And Highbury Catchments, Leon Van Wyk, Gregory Paul Raper

Resource management technical reports

No abstract provided.

Absorption Spectral Slopes And Slope Ratios As Indicators Of Molecular Weight, Source, And Photobleaching Of Chromophoric Dissolved Organic Matter, John R. Helms, Aron Stubbins, Jason D. Ritchie, Elizabeth C. Minor, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

A new approach for parameterizing dissolved organic matter ( DOM) ultraviolet-visible absorption spectra is presented. Two distinct spectral slope regions ( 275-295 nm and 350-400 nm) within log-transformed absorption spectra were used to compare DOM from contrasting water types, ranging from wetlands (Great Dismal Swamp and Suwannee River) to photobleached oceanic water ( Atlantic Ocean). On the basis of DOM size-fractionation studies ( ultrafiltration and gel filtration chromatography), the slope of the 275-295- nm region and the ratio of these slopes (S_R; 275-295- nm slope : 350-400- nm slope) were related to DOM molecular weight ( MW) and …

Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer

United States Geological Survey: Staff Publications

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L^-1 and MeHg was less than 0.2 ng L^-1. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with …

Interagency Science And Research Strategy, Limnological Assistance For Lake Mead National Recreation Area

Limnological Studies

Helping improve operational efficiency, enhance land stewardship, resource protection, and conservation on the shared public land.

Ecological Consequences Of Invasion Of The Quagga Mussel (Dreissena Bugensis Andrusov 1897) Into Lake Mead, David Wong, Shawn Gerstenberger, Todd Tietjen, Sara Ann Mueting, Eric Michael Loomis

Limnological Studies

Consequences of Invasion of the Quagga Mussel into Lake Mead

Estimation Of Submarine Groundwater Discharge From Bulk Ground Electrical Conductivity Measurements, Thomas Stieglitz, John Rapaglia, Henry Bokuniewicz

Biology Faculty Publications

The utility of bulk ground conductivity (BGC) measurements in the estimation of submarine groundwater discharge (SGD) was investigated at four sites covering a range of hydrogeological settings, namely Cockburn Sound (Australia); Shelter Island (USA); Ubatuba Bay (Brazil) and Flic-en-Flac Bay (Mauritius). At each of the sites, BGC was surveyed in the intertidal zone, and seepage meters were used for direct measurements of SGD flow rates. In the presence of detectable salinity gradients in the sediment, a negative correlation between SGD and BGC was recorded. The correlation is site-specific and is dependent on both the type of sediment and the mixing …

Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Dimethylsulfide (DMS) atmospheric and oceanic concentrations and eddy covariance air/sea fluxes were measured over the N. Atlantic Ocean during July 2007 from Iceland to Woods Hole, MA, USA. Seawater DMS levels north of 55 degrees N ranged from 3 to 17 nM, with variability related to the satellite-derived distributions of coccoliths and to a lesser extent, chlorophyll. For the most intense bloom region southwest of Iceland, DMS air/sea fluxes were as high as 300 mu mol m(-2) d(-1), larger than current model estimates. The observations imply that gas exchange coefficients in this region are significantly greater than those estimated using …

Floristic Records In The Platte And Loup River Bottomlands Of Platte County, Nebraska, Michael P. Gutzmer, Robert B. Kaul

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A recent inventory of vascular plants in the Loup and Platte riverbottoms in Platte County has greatly increased knowledge of the area's flora. Of the 542 species of vascular plants now known to grow in the county, 289 were discovered after 1977, with more than 100 of those after 1990. 425 native and 117 naturalized species are known so far. Nearly 700 native and naturalized alien species are expected to occur in the county, based upon totals from nearby counties. Thus, almost 150 years after European settlement, more than 20% of the species remain unverified; of those, many are undoubtedly …

Limnological Assistance For The Lake Mead National Recreation Area In Meeting The Challenge Of The Water 2025 Initiative: Quarterly Progress Report, Period Ending: December 31, 2007, Margaret N. Rees

Limnological Studies

• The limnologist position has been announced.
• Project 1: Review of the draft Boulder Basin Adaptive Management Plan is underway.
• Project 2: Development of a white paper expressing the joint needs of the entities involved in Water 2025 projects is being coordinated.
• Project 3: A bibliographic reference spreadsheet organizing literature citations related to quagga and zebra mussel research has been completed.
• Project 4: A comprehensive literature search of Lake Mead limnology is well underway; an Access database has been designed to organize reference citations; and a special collections library at UNLV is being established to house original rare documents and other …

Histopathological Assessment And Comparison Sedimentation And Phosphate Stress On The Staghorn Coral, Acropora Cervicornis, Erin Christine Hodel

HCNSO Student Theses and Dissertations

Traditional coral reef monitoring efforts lack assessment of coral health at tissue and cellular levels. This thesis investigated tissue, cellular, and gross morphological responses of the Caribbean staghorn coral, Acropora cervicornis, to elevated sedimentation and phosphate using state-of-the-art histological techniques. Branch fragments of A. cervicornis were collected offshore Broward County, FL, acclimated for 12 weeks, subjected to a 4-week experimental period, and given a 1-week recovery period in laboratory aquaria. Treatments consisted of high doses (200 mg cm^-2 day^-1) of sedimentation (S), phosphate (4 μM) (P), and a combination of these two (S + P), in …

Fish And Coral Reef Communities Of The Parque Nacional Sistema Arrecifal Veracruzano (Veracruz Coral Reef System National Park) Veracruz, Mexico: Preliminary Results, Marcos Alberto Rangel Avalos, Lance K. B. Jordan, Brian K. Walker, David S. Gilliam, Elvira Carvajal Hinojosa, Richard E. Spieler

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Effective resource management requires robust baseline datasets and efficient monitoring programs to identify and quantify temporal change. The Parque Nacional Sistema Arrecifal Veracruzano (Veracruz Coral Reef System National Park) encompasses a total of 52000ha including 23 coral reefs in two island groups separated by the mouth of the Jamapa River; one near the port of Veracruz, Mexico and one approximately 20km south near Punta Antón Lizardo. Both groups receive substantial fisheries pressure and other anthropogenic impacts. Using non-destructive, visual methods we surveyed fish and benthic assemblages at 18 sites, which included 10 individual coral reefs within the Park. For fishes, …

Eutrophication In Farmington Bay And Its Potential Impacts On Wildlife, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

No abstract provided.

Benthic Mapping For Habitat Classification In The Peconic Estuary: Phase I Groundtruth Studies, Robert M. Cerrato, Nicole P. Maher

School of Marine & Atmospheric Sciences Faculty Publications

Benthic habitat maps of the estuary seafloor will increase our knowledge of range and variability in benthic habitats, will assist managers in their efforts to protect and/or restore commercially and recreationally important finfish and shellfish, will link land usage (e.g. developed vs. undeveloped areas) and water quality data to benthic habitat quality, and will make it possible to utilize faunal data as a long-term indicator of the overall “health” of the estuary. We are developing benthic habitat maps by combining high-resolution remote sensing techniques with detailed study of the physical and faunal characteristics at point locations in different seafloor environments. …

Soil Survey Of The Bettink Dairy Farm, Riverway Road, Northcliffe, Peter J. Tille, Tilwin Westrup

Resource management technical reports

This soil survey of the Bettink dairy farm in Northcliffe, Western Australia aimed to: provide detailed soil descriptions to add to information associated with the environment in which the dairy industry in Western Australia is located; collect soil samples at predetermined standard depths from documented farm locations for nutrient analysis; map soils with similar characteristics based on description and analysis.

Limb Regeneration After Multiple Autotomy And Coxae Removal In The Blue Crab Callinectes Sapidus, Jennifer Ambler

OES Theses and Dissertations

This study investigated limb regeneration in the juvenile blue crab, Callinectes sapidus, specifically the role of the coxa and pedal nerve innervation of the regenerative limb bud over time. The coxa is a leg segment that has been defined as the source of positional, cellular, and neuronal information needed for limb regeneration in brachyuran crabs. This study indicates that removal of coxae under regenerative and non-regenerative conditions did not deter limb regeneration. The coxa is not the exclusive location of limb regenerative information since limbs re-grew with normal positional and functional arrangement in 86% of crabs showing regeneration at removal …