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Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems
Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152127
- ISBN
- 9798383647998
- DDC
- 551
- 서명/저자
- Effects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems
- 발행사항
- [Sl] : University of California, Los Angeles, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 222 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-02, Section: B.
- 주기사항
- Advisor: Treude, Tina Irene.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2024.
- 초록/해제
- 요약The 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.
- 일반주제명
- Biogeochemistry
- 일반주제명
- Biological oceanography
- 일반주제명
- Chemical oceanography
- 일반주제명
- Aquatic sciences
- 일반주제명
- Geochemistry
- 키워드
- Anoxia
- 키워드
- Hypersaline lake
- 키워드
- Microbial mat
- 키워드
- Nitrogen cycling
- 기타저자
- University of California, Los Angeles Geochemistry 0393
- 기본자료저록
- Dissertations Abstracts International. 86-02B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017163035
■00520250211152127
■006m o d
■007cr#unu||||||||
■020 ▼a9798383647998
■035 ▼a(MiAaPQ)AAI31482808
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a551
■1001 ▼aYousavich, David John.
■24510▼aEffects of Transient Deoxygenation on Sulfur Cycling in Aquatic Systems
■260 ▼a[Sl]▼bUniversity of California, Los Angeles▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a222 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-02, Section: B.
■500 ▼aAdvisor: Treude, Tina Irene.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2024.
■520 ▼aThe 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.
■590 ▼aSchool code: 0031.
■650 4▼aBiogeochemistry
■650 4▼aBiological oceanography
■650 4▼aChemical oceanography
■650 4▼aAquatic sciences
■650 4▼aGeochemistry
■653 ▼aAnoxia
■653 ▼aHypersaline lake
■653 ▼aMicrobial mat
■653 ▼aNitrogen cycling
■653 ▼aOxygen minimum zone
■653 ▼aSulfate reduction
■690 ▼a0425
■690 ▼a0416
■690 ▼a0403
■690 ▼a0996
■690 ▼a0792
■71020▼aUniversity of California, Los Angeles▼bGeochemistry 0393.
■7730 ▼tDissertations Abstracts International▼g86-02B.
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17163035▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
