Anoxic Water in the Pettaquamscutt River1

Gaines, Arthur G.; Pilson, Michael E. Q.

doi:10.4319/lo.1972.17.1.0042

Cited by 50 publications

(25 citation statements)

References 8 publications

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“…1). The Upper Pond (maximum depth 13.5 m, surface area 0.29 km 2 ) is one of two brackish basins, separated from one another by shallow sills, located in North Kingstown, Rhode Island, USA 39 . Except for the complete water column overturn that occurs every 5 to 10 years 39 , the water column stratification in Upper Pond is maintained year-round mainly by the salinity contrast between its two water sources: the Gilbert Stuart Stream and the Rhode Island Sound 39 .…”

Section: Resultsmentioning

confidence: 99%

Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle

et al. 2014

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Of the two nanocrystal (magnetosome) compositions biosynthesized by magnetotactic bacteria (MTB), the magnetic properties of magnetite magnetosomes have been extensively studied using widely available cultures, while those of greigite magnetosomes remain poorly known. Here we have collected uncultivated magnetite-and greigite-producing MTB to determine their magnetic coercivity distribution and ferromagnetic resonance (FMR) spectra and to assess the MTB-associated iron flux. We find that compared with magnetite-producing MTB cultures, FMR spectra of uncultivated MTB are characterized by a wider empirical parameter range, thus complicating the use of FMR for fossilized magnetosome (magnetofossil) detection. Furthermore, in stark contrast to putative Neogene greigite magnetofossil records, the coercivity distributions for greigite-producing MTB are fundamentally left-skewed with a lower median. Lastly, a comparison between the MTB-associated iron flux in the investigated estuary and the pyritic-Fe flux in the Black Sea suggests MTB play an important, but heretofore overlooked role in euxinic marine system iron cycle.

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Section: Resultsmentioning

confidence: 99%

Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle

et al. 2014

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“…The 'change in alkalinity, AAlk, between overturn and some later time is therefore: production in anoxic saline waters (Knull and Richards 1969;Gaines and Pilson 1972) and in anoxic porewaters (Berner et al 1970;Murray et al 1978).…”

Section: Resultsmentioning

confidence: 99%

Mechanisms of hydrogen ion neutralization in an experimentally acidified lake

Cook

Kelly

Schindler

et al. 1986

Limnology & Oceanography

179

114

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The experimental acidification of Lake 223 (Experimental Lakes Area, northwestern Ontario) with sulfuric acid in 1976-1983 allowed a detailed examination of the capacity of the lake to neutralize hydrogen ion. A whole-lake alkalinity and ion budget for Lake 223 showed that 66-81% of the added sulfuric acid was neutralized by alkalinity production in the lake. Nearly 85% of in situ alkalinity production was accounted for by net loss of sulfate through bacterial sulfate reduction, coupled with iron reduction and iron sulfide formation, in littoral sediments (60%) and in the hypolimnion (25%). Exchange of hydrogen ion for calcium and manganese in the sediments accounted for 19% of the alkalinity generated, while other cations were net sinks for alkalinity. Alkalinity input from the watershed of Lake 223 was very small, averaging about 5% of that produced in the lake.The seasonal production of 1,000 peq liter-* alkalinity in the anoxic hypolimnion of this softwater lake could be attributed to bacterial sulfate reduction coupled with iron sulfide formation, ammonium production, and iron (II) production. Only the alkalinity produced from bacterial sulfate reduction coupled with iron sulfide formation remained throughout the annual cycle.

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“…Sulfate reduction reactions in sediments result in a buildup of dissolved reactive phosphate (Pod3-), ammonium (NH,') and alkalinity in pore waters which may be orders of magnitude more concentrated than in the overlying seawater (Sholkovitz, 1973;Berner, 1974;Suess, 1976). The stoichiometry of sulfate reduction as expressed by the equation of Richards (1965) has been used, with some success, to describe sedimentary nutrient regeneration (Gaines and Pilson, 1972;Berner, 1977;Martens et al, 1978;Gaudette and Lyons, 1980). Hence sulfate concentration depth pro-@ Inter-Research/Printed in F. R. Germany files can be used to calculate theoretical nutrient regeneration rates using diagenetic models (Berner, 1974(Berner, , 1977Martens et al, 1978).…”

Section: Introductionmentioning

confidence: 99%

Biogeochemistry of Nearshore Bermuda Sediments. I. Sulfate Reduction Rates and Nutrient Generation

Hines¹,

Lyons²

1982

Mar. Ecol. Prog. Ser.

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Sulfate reduction rates, enumeration of sulfate-reducing bacteria, as well as pore water concentrations of NH,+ and titration alkalinity were determined for the upper 14 cm of sediments collected from 3 nearshore Bermudian environments: Coot Pond (LG), Mangrove Bay (MB) and Devil's Hole (DH). Sulfate reduction rates were rapld at LG and MB but slow at DH (-300 and 8.0 nmoles ml-' d-', respectively). Differences in source and deposition of organic matter caused rate variations. There was a linear relationship between sulfate reduction rates and sulfate-reducing bacteria. Pore water nutrient concentrations were low compared to clastic sediments. Nutrient regeneration rates, as calculated from organic matter C:N.P ratios, and sulfate reduction rates were used to calculate the turnover times of dissolved Pod3-and NH,+. Sediments subject to active bioturbation had NH,' turnover times 9 to 63 times less than those for non-bioturbated sediments

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Anoxic Water in the Pettaquamscutt River1

Cited by 50 publications

References 8 publications

Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle

Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle

Mechanisms of hydrogen ion neutralization in an experimentally acidified lake

Biogeochemistry of Nearshore Bermuda Sediments. I. Sulfate Reduction Rates and Nutrient Generation

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