Biogeochemistry Commons^™

Introduction To Special Section: Saz Project, T. W. Trull, Peter N. Sedwick, F. B. Griffiths, S. R. Rintoul

OES Faculty Publications

Oceanographic processes in the subantarctic region contribute crucially to the phys. and biogeochemical aspects of the global climate system. To explore and quantify these contributions, the Antarctic Cooperative Research Center organized the SAZ Project, a multidisciplinary, multiship study carried out south of Australia in the austral summer of 1997-1998. We present an overview of the SAZ Project and some of its major results.

Effects Of Iron, Silicate, And Light On Dimethylsulfoniopropionate Production In The Australian Subantarctic Zone, G. R. Ditullio, P. N. Sedwick, D. R. Jones, P. W. Boyd, A. C. Crossley, D. A. Hutchins

OES Faculty Publications

Shipboard bottle incubation experiments were performed to investigate the effects of iron, light, and silicate on algal production of particulate dimethylsulfoniopropionate (DMSP_p) in the Subantarctic Zone (SAZ) south of Tasmania during March 1998. Iron enrichment resulted in threefold to ninefold increases in DMSP_p concentrations relative to control treatments, following 7 and 8-day incubation experiments. Additions of Fe and Si preferentially stimulated the growth of lightly-silicified pennate diatoms and siliceous haptophytes, respectively, to which we attribute the increased DMSP_p production in the incubation bottles. Both of these algal groups were previously believed to be low DMSP_{p …}

Iron In East Antarctic Snow: Implications For Atmospheric Iron Deposition And Algal Production In Antarctic Waters, Ross Edwards, Peter N. Sedwick

OES Faculty Publications

To evaluate the deposition and solubility of aerosol iron in the Antarctic seasonal sea ice zone (SSIZ), iron was measured in snow samples collected from three areas in the SSIZ (Prydz Bay, Dumont d'Urville Sea and Ross Sea) and one continental area (Princess Elizabeth Land) of East Antarctica. Concentrations of total-dissolvable iron (that soluble at pH ~2) ranged from 20-2950 pg g^-1, with the lowest concentrations measured in snow from the Dumont d'Urville Sea. Using estimates of snow accumulation rates, we calculate atmospheric iron deposition fluxes of 0.017-0.11 mg m^-2 yr^-1(0.30-2.0 μmol m^-2 yr …

Data Report: Carbon Isotopic Composition Of Dissolved Co2, Co2 Gas, And Methane, Blake-Bahama Ridge And Northeast Bermuda Rise, Odp Leg 172, Walter S. Borowski, Namik Cagatay, Y Tournois, Charles K. Paull

EKU Faculty and Staff Scholarship

Carbon isotopic data of interstitial dissolved CO2 (ΣCO2), CO2 gas, and methane show that a variety of microbial diagenetic processes produce the observed isotopic trends. Anaerobic methane oxidation (AMO) is an important process near the sulfate-methane interface (SMI) that strongly influences the isotopic composition of ΣCO2 in the sulfate reduction and upper methanogenic zones, which in turn impacts methane isotopic composition. Dissolved CO2 and methane are maximally depleted in 3C near the SMI, where C values are as light as –31.8‰ and –101‰ PDB for ΣCO2 and methane, respectively. CO2 reduction links the CO2 and methane pools in the methanogenic …

Modifications Of The C37 Alkenone And Alkenoate Composition In The Water Column And Sediment: Possible Implications For Sea Surface Temperature Estimates In Paleoceanography, Joan O. Grimalt, Jürgen Rullkötter, Marie-Alexandrine Sicre, Roger Summons, John Farrington, H. Rodger Harvey, Miguel Goñi, Ken Sawada

OES Faculty Publications

The literature pertaining to C37 alkenone and C37 and C38 alkenoate production and diagenesis has been reviewed and evaluated for issues that might jeopardize their usefulness in paleotemperature estimation. We also examined the use of the C37 alkenones as paleoproductivity indicators, the stability of their δ13C isotopic compositions, and their incorporation into the nonsolvent extractable organic matter fraction. Biological transformation of organic matter by bacteria and zooplankton does not appear to cause significant changes to the ratio of C37:2 and C37:3 alkenones, but there are major alterations in the relative composition of alkenoates. Studies of water column processes and postdepositional …

Alteration Processes Of Alkenones And Related Lipids In Water Columns And Sediments, H. Rodger Harvey

OES Faculty Publications

Alkenones produced by the haptophyte algae are currently being used as indices of sea surface temperature in recent and past ocean environments, but limited information is available concerning the impact of biotic and abiotic processes on the integrity of these long chain lipids. This synthesis provides selected background information on major alteration processes that must be considered before such indices can be used with confidence. A number of processes in the water column and surface sediments have the potential to impact the structural integrity of alkenones and compromise their ability as temperature markers. Processes discussed include the alteration of alkenone …

Iron And Manganese In The Ross Sea, Antarctica: Seasonal Iron Limitation In Antarctic Shelf Waters, Peter N. Sedwick, Giacomo R. Ditullio, Denis J. Mackey

OES Faculty Publications

Dissolved iron and manganese and total dissolvable iron were measured in water column samples from the Polynya Region of the southern Ross Sea in cruises in Nov.-Dec. 1994 (spring 1994) and Dec. 1995 to Jan. 1996 (summer 1995). Iron and manganese addition bottle incubation experiments were also performed on these cruises to assess the nutritional sufficiency of ambient iron and manganese concentrations for phytoplankton growth. Generally high dissolved iron concentrations (>0.5 nM) and relatively complex iron and manganese vertical profiles were obtained in spring 1994 vs. summer 1995. Dissolved iron concentrations in the upper water column averaged 1.0 nM …

Nitrogen Isotopic Composition Of Pore Water Ammonium, Blake Ridge, Site 997, Odp Leg 164, Walter S. Borowski, Charles K. Paull

EKU Faculty and Staff Scholarship

Ammonium (NH4 +) concentration profiles in piston-core sediments of the Carolina Rise and Blake Ridge generally have linear concentration profiles within the sulfate reduction zone (Borowski, 1998). Deep Sea Drilling Project (DSDP) Site 533, located on the Blake Ridge, also displayed a linear ammonium concentration profile through the sulfate reduction zone and the profile linearity continues into the upper methanogenic zone to a depth of ~200 meters below seafloor (mbsf), where the first methane gas hydrates probably occur (Jenden and Gieskes, 1983; Kvenvolden and Barnard, 1983). Sediments from the Ocean Drilling Program (ODP) Leg 164 deep holes (Sites 994, 995, …

Significance Of Anaerobic Methane Oxidation In Methane-Rich Sediments Overlying The Blake Ridge Gas Hydrates, Walter S. Borowski, Tori M. Hoehler, Mark J. Alperin, Namcy M. Rodriguez, Charles K. Paull

EKU Faculty and Staff Scholarship

A unique set of geochemical pore-water data, characterizing the sulfate reduction and uppermost methanogenic zones, has been collected at the Blake Ridge (offshore southeastern North America) from Ocean Drilling Program (ODP) Leg 164 cores and piston cores. The δ13 C values of dissolved CO2(Σ CO2) are as 13 C-depleted as –37.7‰ PDB (Site 995) at the sulfate-methane interface, reflecting a substantial contribution of isotopically light carbon from methane. Although the geochemical system is complex and difficult to fully quantify, we use two methods to constrain and illustrate the intensity of anaerobic methane oxidation in Blake Ridge sediments. An estimate using …

A Biogeochemical Comparison Of Fossil (Carboniferous) And Modern Crustose Red Algae, Michael A. Kruge, John E. Utgaard, William Ferry

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The nature of the contribution of the various types of algae to sedimentary organic matter continues to be a topic of research interest. Crustose red algae have however received less attention than other types. The fossil calcareous red algae (Rhodophyta) analyzed in this study are two relatively unrecrystallized specimens of Parachaetetes (Family Solenoporacea) from the lower part of the Ste. Genevieve Formation (Carboniferous, Visean) in Union County, Illinois, USA. They occurred in the patch reef phase of a small carbonate mudmound-patchreef. The three modern specimens (collected and identified by F. Collier) are the crustose algae Lithothamnion, Clathromorphum and Phymatolithon …

Physical Control Of Biological Processes In The Central Equatorial Pacific: A Data Assimilative Modeling Study, Marjorie Anne Macwhorter Friedrichs

OES Theses and Dissertations

A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes included in the ecosystem model respond to environmental fluctuations with time scales between one and ten days, which are not typically resolved by basin to global scale circulation models. Therefore, the ecosystem model is forced using daily observations from the TAO mooring array. Model simulations successfully reproduce data collected both during and after the 1991–92 El …

Limitation Of Algal Growth By Iron Deficiency In The Australian Subantarctic Region, Peter N. Sedwick, Giacomo R. Ditullio, David A. Hutchins, Philip W. Boyd, F. Brian Griffiths, A. Clive Crossley, Thomas W. Trull, Bernard Queguiner

OES Faculty Publications

In March 1998 we measured iron in the upper water column and conducted iron- and nutrient-enrichment bottle-incubation experiments in the open-ocean Subantarctic region southwest of Tasmania, Australia. In the Subtropical Convergence Zone (∼42°S, 142°E), silicic acid concentrations were low (< 1.5μM) in the upper water column, whereas pronounced vertical gradients in dissolved iron concentration (0.12-0.84 nM) were observed., presumably reflecting the interleaving of Subtropical and Subantarctic waters, and mineral aerosol input. Results of a bottle-incubation experiment performed at this location indicate that phytoplankton growth rates were limited by iron deficiency within the iron-poor layer of the euphotic zone. In the Subantarctic water mass (∼46.8°S, 142°E), low concentrations of dissolved iron (0.05-0.11nM) and silicic acid (< 1μM) were measured throughout the upper water column, and our experimental results indicate that algal growth was limited by iron deficiency. These observations suggest that availability of dissolved iron is a primary factor limiting phytoplankton growth over much of the Subantarctic Southern Ocean in the late summer and autumn.

New Technique Detects Gas Hydrates, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

As exploration and development moves into deep waters, the possibility of encountering gas hydrates within seafloor sediments becomes increasingly likely. The ability to accurately detect gas hydrates is key to producing deepwater fields, allowing operators to safely design and place offshore drilling and production platforms, subsea production equipment and flow lines, as well as pipelines.

Iron In Ice Cores From Law Dome, East Antarctica: Implications For Past Deposition Of Aerosol Iron, R. Edwards, Peter N. Sedwick, Vin Morgan, C. F. Boutron, S. Hong

OES Faculty Publications

Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal …

Lead Isotopes And Selected Metals In Ice From Law Dome, Antarctica, K. J. R. Rosman, W. Chisholm, C. F. Boutron, S. Hong, R. Edwards, Vin Morgan, Peter N. Sedwick

OES Faculty Publications

The isotopic composition. of Pb and the concentrations of Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East Antarctica, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03-1.5 pg g^-1 for Pb, 0.9-6.1 pg g^-1 for Ba and 0.4-17 fg g^-1 for Bi, excluding the deepest sample which contained ∼1 ppm of rock dust. The abundances of all four stable lead isotopes were measured and gave ²⁰⁶Pb/²⁰⁷Pb ratios ≤ ∼1.23. A value of ²⁰⁸Pb/²⁰⁷Pb = 2.78 was measured in …

Resource Use In The Trinational Sangha River Region Of Equatorial Africa: Histories, Knowledge Forms, And Institutions, Heather E. Eves, Rebecca Hardin, Stephanie Rupp

Yale School of the Environment Bulletin Series

This volume is based on an international conference, “Natural Resource Use Relations in the Trinational Sangha River Region of the Northwest Congo Basin,” held at Yale University in September 1997. In recognition of the bilingual context in which conservation occurs in the three countries of the Sangha region — Cameroon, Central African Republic, and Congo — all sessions of the conference were conducted simultaneously in French and English. This publication, which is a complete rendering of the conference papers and discussion sessions, is available in its entirety in both French and English.

The Migration Of Arsenic And Lead In Surface Sediments At Three Kids Mine Henderson, Nevada, Douglas Brian Sims

Publications (WR)

This study focused on the distribution of arsenic and lead in surface sediments at Three Kids Mine in Henderson, Nevada. The mine site encompasses approximately 470 acres of desert and is situated above two developing communities (Lake Las Vegas and Calico Ridge) and the Las Vegas Valley's water source (Lake Mead). Transport of arsenic and lead appears to have occurred within a limited range in both the eastern and western washes on the eastern and western sides of Three Kids Mine. Concentrations of arsenic range between 20 mg/kg (ppm) and 1130 mg/kg and between 20 mg/kg and 8400 mg/kg for …

Biostratigraphic Analysis Of Southern Florida's Plio-Pleistocene Shell Beds, Dalton L. Rasmussen

OES Theses and Dissertations

Four molluscan assemblage zones in southern Florida corresponding to the Pinecrest Sand Member of the Tamiami Formation, and the Caloosahatchee, Bermont and Fort Thompson shell beds were identified following quantitative and qualitative analyses of the fossil molluscan fauna. Twenty-eight bulk sediment samples collected from 16 localities across southern Florida were processed for fossil material, and yielded nearly 60,000 specimens belonging to 311 species. A Q-mode cluster analysis compared sediment samples on the basis of 188 species whose abundances had been converted to binary presence-absence form. The cluster analysis was run four times using the Jaccard and Dice similarity coefficients as …

Fluxes Of Copper-Complexing Ligands From Estuarine Sediments, Stephen A. Skrabal, John R. Donat, David J. Burdige

OES Faculty Publications

Most studies of the organic complexation of Cu in natural waters have focused on distributions and processes in the water column, where a significant fraction of Cu-complexing ligands may be biologically produced. We present direct evidence for a flux of Cu-complexing ligands from estuarine sediments, demonstrating that sediments are a significant, yet previously unrecognized source of the ligands. Fluxes of Cu-complexing ligands from Chesapeake Bay sediments range from 300 to 1,200 nmol m^-2 d^-1, exceeding fluxes of total dissolved Cu by 3->40-fold, suggesting that any Cu fluxing from the sediments is likely to be organically complexed. …

Regulation Of Algal Blooms In Antarctic Shelf Waters By The Release Of Iron From Melting Sea Ice, Peter N. Sedwick, Giacomo R. Ditullio

OES Faculty Publications

During summer 1995-96, we measured iron in the water column and conducted iron-enrichment bottle-incubation experiments at a station in the central Ross Sea (76°30'S, 170°40'W), first, in the presence of melting sea ice, and 17 days later, in ice-free conditions. We observed a striking temporal change in mixed-layer dissolved iron concentrations at this station, from 0.72-2.3 nM with sea ice present, to 0.16-0.17 nM in ice-free conditions. These changes were accompanied doubling of algal (diatom) biomass. Our incubation experiments suggest that conditions were iron-replete in the presence of sea ice, and iron-deficient in the absence of sea ice. We surmise …

Factors Affecting Nitrogen Fixation Rates In Termites (Isoptera: Rhinotermitidae: Reticulitermes) And Termite Nitrogen Contributions Of Forest Ecosystems, Anthony Duane Curtis

Biological Sciences Theses & Dissertations

Termites host symbiotic bacteria that fix atmospheric nitrogen, which makes termites important in the biogeochemical cycling of nitrogen in ecosystems. The objective of this study was to estimate annual nitrogen contributions by termites by examining seasonal rates of nitrogen fixation, seasonal abundance of different termite castes and their nitrogenase activity, the effects of dietary nitrogen on nitrogenase activity, and low oxygen and high carbon dioxide atmospheres on termite nitrogenase activity, and the accuracy of mark-recapture studies to estimate termite population size.

Termite nitrogen fixation rates were monitored monthly for 10 Reticulitermes Holmgren colonies from June, 1993, to December, 1995. Rates …

A Coupled, Non-Linear, Steady State Model For Early Diagenetic Processes In Pelagic Sediments, Surya P. Dhakar, David J. Burdige

OES Faculty Publications

A steady state, coupled, non-linear model has been developed for early diagenetic processes in pelagic and hemi-pelagic marine sediments. Model results show that the occurrence of oxic and sub-oxic diagenetic processes is significantly affected by variations in parameters such as the sedimentation rate, bioturbation coefficient, sediment porosity, and organic matter flux to the sediments. Increases in the sedimentation rate or the bioturbation coefficient increase organic matter oxidation by sub-oxic processes, whereas an increase in sediment porosity decreases organic matter oxidation by sub-oxic processes. Sediment data from three contrasting MANOP sites are fit reasonably well with the model. The resulting best-fit …

Biogenic Matter Diagenesis On The Sea Floor: A Comparison Between Two Continental Margin Transects, William M. Berelson, Jim Mcmanus, Kenneth H. Coale, Kenneth S. Johnson, Tammy Kilgore, David J. Burdige, Cynthia Pilskaln

OES Faculty Publications

Benthic chamber measurements of the reactants and products involved with biogenic matter diagenesis (oxygen, ammonium, nitrate, silicate, phosphate, TCO₂, alkalinity) were used to define fluxes of these solutes into and out of the sediments off southern and central California. Onshore to offshore transects indicate many similarities in benthic fluxes between these regions. The pattern of benthic organic carbon oxidation as a function of water depth, combined with published sediment trap records, suggest that the supply of organic carbon from vertical rain can just meet the sedimentary carbon oxidation + burial demand for the central California region between the …

Synthetic Organic Compounds: Las Vegas Wash And Lake Mead, National Water Quality Assessment Program (Nawqa): Nevada Basin And Range

Publications (WR)

The Nevada Basin and Range (NVBR) study unit of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is investigating the status of, trends in, and factors affecting water quality in the Las Vegas area. A principal objective of the investigation is to assess the effects of urbanization on the quality of area water resources. Las Vegas Wash is the surface-water outlet for the Las Vegas area. The wash transports stormwater runoff, shallow ground-water discharge, and tertiary-treated sewage effluent from the Las Vegas area to Las Vegas Bay of Lake Mead on the Colorado River. Most of the flow—about 96 …

Copper Complexation Capacity And Copper Speciation In Freshwater Lakes (Lake Western Branch And Lake Prince), Rachide Ibrahimo Abdul Sultana

Chemistry & Biochemistry Theses & Dissertations

This research examines the copper complexation capacity, copper speciation and dissolved copper concentrations in Lake Western Branch (WB) and Lake Prince (LP) both located in Suffolk, Virginia. These lakes are drinking water reservoirs for the cities of Suffolk and Norfolk, and they experience blooms of algae which can deplete them of oxygen and affect treatment of their waters for drinking. Copper sulfate has regularly been added to control the algae, but the effectiveness of these additions is uncertain. For environmental management implications, knowledge of speciation (i.e., the concentrations of the various chemical forms) is important in studying the effects of …

Elimination Of Dissolved Sulfide Interference In The Flow-Injection Determination Of Sigma-Co2 By Addition Of Molybdate, Rigel L. Lustwerk, David J. Burdige

OES Faculty Publications

A previously described flow injection method for the analysis of ΣCO₂ included the addition of ZnCl₂ to some samples before analysis in order to precipitate dissolved sulfide (which interferes with the method) as ZnS. However, the use of Zn²⁺ in samples with high concentrations of dissolved sulfide causes the coprecipitation of ZnCO₃, and in our experience with this technique, ZnCO₃ also precipitates even in the absence of dissolved sulfide. The addition of molybdate effectively complexes dissolved sulfide without interfering with the determination of ΣCO2 by this technique.

Constructed Wetland Design Criteria : A Study Of Their Role In Contaminant Removal From Urban Stormwater Runoff, A. J. Braid

Theses : Honours

This study was conducted to review effective design criteria for constructed wetlaads treating urban stormwater and to assess the design features of local constructed wetlands in relation to the theoretically ideal design features. The study was generated out of Water Authority of Western Australia (WAWA) concern that existing inconsistent design criteria may result in constructed wetlands not meeting contaminant removal objectives. Three components to the study involved: design criteria compiled from a critical review of relevant literature, field assessment of selected sites with significant differences in design, and a design critique of those sites based on the compiled design criteria. …

Indicators Of Nutrient Limited Plankton Growth In Lakes Near Mount Saint Helens, Washington, Kurt Davis Carpenter

Dissertations and Theses

Several lakes located in the blast zone of the 1980 eruption of Mount St. Helens were studied to determine if the plankton in the lakes were limited in their growth by nitrogen or phosphorus availability. Long term nutrient enrichment experiments were performed on lake water from five lakes and measures of chlorophyll-a, carbon fixation, and nutrient uptake were used to evaluate the extent of limitation. Nutrient concentrations, ratios, and uptake from 14 lakes provided additional evidence for limitation by nitrogen and/or phosphorus. The physical, chemical, and biological characteristics of the lakes were also examined to monitor the return of these …

The Dinoflagellate Flora Of The Late Oligocene - Early Miocene Old Church Formation Mid-Atlantic Coastal Plain, Alan P. Hoffmeister

OES Theses and Dissertations

The Old Church Formation contains the only presently known exposed Oligocene sediments in the North American mid-Atlantic Coastal Plain. Some ambiguity concerning the exact age of the Old Church Formation exists because it may include both Oligocene and Miocene sediments. Two outcrops and four cores containing the Old Church Formation were examined for dinoflagellates to determine the composition of the dinoflagellate flora in the Old Church Formation, the age of the Old Church Formation as indicated by this flora, general depositional environment of the Old Church Formation and correlative relationships of the Old Church Formation with other Coastal Plain units. …

The Biogeochemistry Of Hydrogen Sulfide: Phytoplankton Production In The Surface Ocean, Russell S. Walsh, Gregory A. Cutter, William M. Dunstan, Joel Radford-Knoery, Jennifer T. Elder

OES Faculty Publications

Hydrogen sulfide can exist in oxic waters in the form of a dissolved gas, dissociated ions, dissolved metal sulfide complexes, and particulate metal sulfides. The sum of the dissolved species is termed total dissolved sulfide (TDS). In addition to the hydrolysis of carbonyl sulfide, it has been speculated that phytoplankton may produce TDS. We present results from preliminary culture studies which demonstrate that phytoplankton produce TDS and particulate acid-volatile sulfide (pAVS). The phylogenetic order of TDS + pAVS production (per unit cell volume) for the oceanic species examined is Synechococcus sp. > Emiliania huxleyi ≈ Pyramimonas obovata > Thalassiosira oceanica. Moreover, …