Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
<p>The dissolved oxygen (DO) levels of coastal ocean waters have decreased over the last few decades in part because of the increase in surface and subsurface water temperature caused by climate change, the reduction in ocean ventilation, and the increase in stratification and eutrophication....
| Main Authors: | , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2024-03-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/21/1433/2024/bg-21-1433-2024.pdf |
| _version_ | 1827313578700439552 |
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| author | P. Linford P. Linford P. Linford I. Pérez-Santos I. Pérez-Santos I. Pérez-Santos P. Montero P. Montero P. A. Díaz P. A. Díaz C. Aracena C. Aracena E. Pinilla E. Pinilla F. Barrera F. Barrera M. Castillo A. Alvera-Azcárate M. Alvarado G. Soto C. Pujol C. Schwerter S. Arenas-Uribe P. Navarro G. Mancilla-Gutiérrez R. Altamirano J. San Martín C. Soto-Riquelme |
| author_facet | P. Linford P. Linford P. Linford I. Pérez-Santos I. Pérez-Santos I. Pérez-Santos P. Montero P. Montero P. A. Díaz P. A. Díaz C. Aracena C. Aracena E. Pinilla E. Pinilla F. Barrera F. Barrera M. Castillo A. Alvera-Azcárate M. Alvarado G. Soto C. Pujol C. Schwerter S. Arenas-Uribe P. Navarro G. Mancilla-Gutiérrez R. Altamirano J. San Martín C. Soto-Riquelme |
| author_sort | P. Linford |
| collection | DOAJ |
| description | <p>The dissolved oxygen (DO) levels of coastal ocean waters have decreased over the last few decades in part because of the increase in surface and subsurface water temperature caused by climate change, the reduction in ocean ventilation, and the increase in stratification and eutrophication. In addition, biological and human activity in coastal zones, bays, and estuaries has contributed to the acceleration of current oxygen loss. The Patagonian fjord and channel system is one world region where low-DO water (LDOW, 30 %–60 % oxygen saturation) and hypoxia conditions (<span class="inline-formula"><30</span> % oxygen saturation, 2 mL L<span class="inline-formula"><sup>−1</sup></span> or 89.2 <span class="inline-formula">µ</span>mol L<span class="inline-formula"><sup>−1</sup>)</span> are observed. An in situ dataset of hydrographic and biogeochemical variables (1507 stations), collected from sporadic oceanographic cruises between 1970 and 2021, was used to evaluate the mechanisms involved in the presence of LDOW and hypoxic conditions in northern Patagonian fjords. Results denoted areas with LDOW and hypoxia coinciding with the accumulation of inorganic nutrients and the presence of salty and oxygen-poor Equatorial Subsurface Water mass. The role of biological activity in oxygen reduction was evident in the dominance of community respiration over gross primary production. This study elucidates the physical and biogeochemical processes contributing to hypoxia and LDOW in the northern Patagonian fjords, highlighting the significance of performing multidisciplinary research and combining observational and modeling work. This approach underscores the<span id="page1434"/> importance of a holistic understanding of the subject, encompassing both real-world observations and insights provided by modeling techniques.</p> |
| first_indexed | 2024-04-24T22:18:08Z |
| format | Article |
| id | doaj.art-1407f524810746af9484c0b5b790199a |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-04-24T22:18:08Z |
| publishDate | 2024-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-1407f524810746af9484c0b5b790199a2024-03-20T06:57:10ZengCopernicus PublicationsBiogeosciences1726-41701726-41892024-03-01211433145910.5194/bg-21-1433-2024Oceanographic processes driving low-oxygen conditions inside Patagonian fjordsP. Linford0P. Linford1P. Linford2I. Pérez-Santos3I. Pérez-Santos4I. Pérez-Santos5P. Montero6P. Montero7P. A. Díaz8P. A. Díaz9C. Aracena10C. Aracena11E. Pinilla12E. Pinilla13F. Barrera14F. Barrera15M. Castillo16A. Alvera-Azcárate17M. Alvarado18G. Soto19C. Pujol20C. Schwerter21S. Arenas-Uribe22P. Navarro23G. Mancilla-Gutiérrez24R. Altamirano25J. San Martín26C. Soto-Riquelme27Programa de Doctorado en Ciencias, Mención Conservación y Manejo de Recursos Naturales, Universidad de Los Lagos, Puerto Montt, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCenter for Oceanographic Research COPAS Sur-Austral and COPAS COASTAL, Universidad de Concepción, Concepción, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCenter for Oceanographic Research COPAS Sur-Austral and COPAS COASTAL, Universidad de Concepción, Concepción, ChileCentro de Investigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, ChileCenter for Oceanographic Research COPAS Sur-Austral and COPAS COASTAL, Universidad de Concepción, Concepción, ChileCentro de Investigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCeBiB, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCentro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O'Higgins, Avenida Viel 1497, Santiago, ChileLaboratorio Costero de Recursos Acuáticos de Calfuco, Universidad Austral de Chile, Valdivia, ChileInstituto de Fomento Pesquero (IFOP), CTPA Putemún, Castro, ChileDepartment of Civil and Environmental Engineering, University of Maine, Orono, ME, USAFundación Bariloche and CONICET, San Carlos de Bariloche, ArgentinaCentro Austral de Investigaciones Científicas (CADIC), CONICET, Bernardo Houssay 200, Ushuaia, ArgentinaCentro de Observación Marino para Estudios de Riesgos del Ambiente Costero, Universidad de Valparaíso, Valparaíso, ChileAGO-GHER, University of Liège, Liège, BelgiumServicio Hidrográfico y Oceanográfico de la Armada de Chile, Valparaíso, ChileInstituto de Fomento Pesquero (IFOP), CTPA Putemún, Castro, ChileAGO-GHER, University of Liège, Liège, BelgiumCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileCentro i-mar, Universidad de Los Lagos, Casilla 557, Puerto Montt, ChileInstituto de Fomento Pesquero (IFOP), CTPA Putemún, Castro, ChileInstituto de Fomento Pesquero (IFOP), CTPA Putemún, Castro, Chile<p>The dissolved oxygen (DO) levels of coastal ocean waters have decreased over the last few decades in part because of the increase in surface and subsurface water temperature caused by climate change, the reduction in ocean ventilation, and the increase in stratification and eutrophication. In addition, biological and human activity in coastal zones, bays, and estuaries has contributed to the acceleration of current oxygen loss. The Patagonian fjord and channel system is one world region where low-DO water (LDOW, 30 %–60 % oxygen saturation) and hypoxia conditions (<span class="inline-formula"><30</span> % oxygen saturation, 2 mL L<span class="inline-formula"><sup>−1</sup></span> or 89.2 <span class="inline-formula">µ</span>mol L<span class="inline-formula"><sup>−1</sup>)</span> are observed. An in situ dataset of hydrographic and biogeochemical variables (1507 stations), collected from sporadic oceanographic cruises between 1970 and 2021, was used to evaluate the mechanisms involved in the presence of LDOW and hypoxic conditions in northern Patagonian fjords. Results denoted areas with LDOW and hypoxia coinciding with the accumulation of inorganic nutrients and the presence of salty and oxygen-poor Equatorial Subsurface Water mass. The role of biological activity in oxygen reduction was evident in the dominance of community respiration over gross primary production. This study elucidates the physical and biogeochemical processes contributing to hypoxia and LDOW in the northern Patagonian fjords, highlighting the significance of performing multidisciplinary research and combining observational and modeling work. This approach underscores the<span id="page1434"/> importance of a holistic understanding of the subject, encompassing both real-world observations and insights provided by modeling techniques.</p>https://bg.copernicus.org/articles/21/1433/2024/bg-21-1433-2024.pdf |
| spellingShingle | P. Linford P. Linford P. Linford I. Pérez-Santos I. Pérez-Santos I. Pérez-Santos P. Montero P. Montero P. A. Díaz P. A. Díaz C. Aracena C. Aracena E. Pinilla E. Pinilla F. Barrera F. Barrera M. Castillo A. Alvera-Azcárate M. Alvarado G. Soto C. Pujol C. Schwerter S. Arenas-Uribe P. Navarro G. Mancilla-Gutiérrez R. Altamirano J. San Martín C. Soto-Riquelme Oceanographic processes driving low-oxygen conditions inside Patagonian fjords Biogeosciences |
| title | Oceanographic processes driving low-oxygen conditions inside Patagonian fjords |
| title_full | Oceanographic processes driving low-oxygen conditions inside Patagonian fjords |
| title_fullStr | Oceanographic processes driving low-oxygen conditions inside Patagonian fjords |
| title_full_unstemmed | Oceanographic processes driving low-oxygen conditions inside Patagonian fjords |
| title_short | Oceanographic processes driving low-oxygen conditions inside Patagonian fjords |
| title_sort | oceanographic processes driving low oxygen conditions inside patagonian fjords |
| url | https://bg.copernicus.org/articles/21/1433/2024/bg-21-1433-2024.pdf |
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