東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Effects of Transient Deoxygenation o...

Yousavich, David John,

Linked to FindBook

Google Book

Amazon

博客來

Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems /

Record Type:	Electronic resources : Monograph/item
Title/Author:	Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems // David John Yousavich.
Author:	Yousavich, David John,
Description:	1 electronic resource (222 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 86-02, Section: B.
Contained By:	Dissertations Abstracts International86-02B.
Subject:	Biogeochemistry. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31482808
ISBN:	9798383647998

Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems /
Yousavich, David John,

Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems /David John Yousavich. - 1 electronic resource (222 pages)

Source: Dissertations Abstracts International, Volume: 86-02, Section: B.

The rise of oxygen in the early Earth atmosphere allowed for a vast expansion of life, including the proliferation of animal life, that could utilize this powerful electron acceptor for new metabolisms. This oxygen requirement has left many organisms vulnerable to oxygen-depleted conditions (i.e., anoxia). These anoxic events in Earth's aquatic environments allow for free iron (ferruginous) or free sulfide (euxinic) conditions to develop. While much research has been done on the past and present of aquatic anoxia, transiently deoxygenated systems that cycle annually between oxygenated and anoxic states are underexplored. Questions about these cycles of aquatic redox state abound; for example, 1) if benthic sulfur-oxidizing bacteria promote free sulfide at the sediment-water interface in transiently deoxygenated systems 2) if these cycles of anoxia can promote a loss of free iron from the benthic marine environment and 3) if sulfate reducing bacteria are quickly established in lacustrine waters after anoxia develops.The first and second questions will be addressed in this dissertation through a suite of investigations in the transiently deoxygenated Santa Barbara Basin. Porewater geochemistry, sulfate reduction rates, and benthic flux measurements were collected between 2019-2023 under varying oxygen concentrations. We found that sulfur-oxidizing bacterial mats in the basin are associated with high rates of dissimilatory nitrate reduction to ammonium and require an elevation of the sulfate reduction zone to the sediment-water interface in order to proliferate. Mat proliferation also requires an exhaustion of iron oxides in the surface sediment. Mat formation is also associated with extremely high fluxes of iron into the water column. This free iron is potentially lost from the basin through bottom water currents that carry mid-waters upslope during the anoxic events.The third question will be addressed in this dissertation by several geochemical and ex-situ sulfate reduction measurements taken in the Salton Sea between 2020-2023 under a variety of water column redox conditions. We found that sulfate reduction is present in waters that contained oxygen, most likely occurring inside organic particles in the water. We also found that sulfate reduction is quickly established after the onset of anoxia in the lake.

English

ISBN: 9798383647998Subjects--Topical Terms:

545717
Biogeochemistry.
Subjects--Index Terms:

Anoxia

Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems /
LDR:03924nmm a22004693i 4500 001 2429200
005 20250430093552.5
006 m o d
007 cr|nu||||||||
008 261011s2024 miu||||||m |||||||eng d
020 $a 9798383647998
035 $a (MiAaPQD)AAI31482808
035 $a AAI31482808
040 $a MiAaPQD $b eng $c MiAaPQD $e rda
100 1 $a Yousavich, David John, $e author. $3 3816907
245 1 0 $a Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems / $c David John Yousavich.
264 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2024
300 $a 1 electronic resource (222 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 86-02, Section: B.
500 $a Advisors: Treude, Tina Irene Committee members: Schauble, Edwin Arthur; Jewitt, David Clifford; Bianchi, Daniele; Valentine, David L.
502 $b Ph.D. $c University of California, Los Angeles $d 2024.
520 $a The rise of oxygen in the early Earth atmosphere allowed for a vast expansion of life, including the proliferation of animal life, that could utilize this powerful electron acceptor for new metabolisms. This oxygen requirement has left many organisms vulnerable to oxygen-depleted conditions (i.e., anoxia). These anoxic events in Earth's aquatic environments allow for free iron (ferruginous) or free sulfide (euxinic) conditions to develop. While much research has been done on the past and present of aquatic anoxia, transiently deoxygenated systems that cycle annually between oxygenated and anoxic states are underexplored. Questions about these cycles of aquatic redox state abound; for example, 1) if benthic sulfur-oxidizing bacteria promote free sulfide at the sediment-water interface in transiently deoxygenated systems 2) if these cycles of anoxia can promote a loss of free iron from the benthic marine environment and 3) if sulfate reducing bacteria are quickly established in lacustrine waters after anoxia develops.The first and second questions will be addressed in this dissertation through a suite of investigations in the transiently deoxygenated Santa Barbara Basin. Porewater geochemistry, sulfate reduction rates, and benthic flux measurements were collected between 2019-2023 under varying oxygen concentrations. We found that sulfur-oxidizing bacterial mats in the basin are associated with high rates of dissimilatory nitrate reduction to ammonium and require an elevation of the sulfate reduction zone to the sediment-water interface in order to proliferate. Mat proliferation also requires an exhaustion of iron oxides in the surface sediment. Mat formation is also associated with extremely high fluxes of iron into the water column. This free iron is potentially lost from the basin through bottom water currents that carry mid-waters upslope during the anoxic events.The third question will be addressed in this dissertation by several geochemical and ex-situ sulfate reduction measurements taken in the Salton Sea between 2020-2023 under a variety of water column redox conditions. We found that sulfate reduction is present in waters that contained oxygen, most likely occurring inside organic particles in the water. We also found that sulfate reduction is quickly established after the onset of anoxia in the lake.
546 $a English
590 $a School code: 0031
650 4 $a Biogeochemistry. $3 545717
650 4 $a Biological oceanography. $3 2122748
650 4 $a Chemical oceanography. $3 516760
650 4 $a Aquatic sciences. $3 3174300
650 4 $a Geochemistry. $3 539092
653 $a Anoxia
653 $a Hypersaline lake
653 $a Microbial mat
653 $a Nitrogen cycling
653 $a Oxygen minimum zone
653 $a Sulfate reduction
690 $a 0425
690 $a 0416
690 $a 0403
690 $a 0996
690 $a 0792
710 2 $a University of California, Los Angeles. $b Geochemistry 0393. $e degree granting institution. $3 3816908
720 1 $a Treude, Tina Irene $e degree supervisor.
773 0 $t Dissertations Abstracts International $g 86-02B.
790 $a 0031
791 $a Ph.D.
792 $a 2024
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=31482808