ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific
El Niño-Southern oscillation (ENSO) is the leading cause of sea surface temperature variability in the tropical Pacific with known impacts on tuna geographic range, but its effects on oxygen and available oxygenated habitat space are less clear. Variations in oxygenated vertical habitat space in the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2019-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab1c13 |
| _version_ | 1797748016306716672 |
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| author | Shirley Leung LuAnne Thompson Michael J McPhaden K A S Mislan |
| author_facet | Shirley Leung LuAnne Thompson Michael J McPhaden K A S Mislan |
| author_sort | Shirley Leung |
| collection | DOAJ |
| description | El Niño-Southern oscillation (ENSO) is the leading cause of sea surface temperature variability in the tropical Pacific with known impacts on tuna geographic range, but its effects on oxygen and available oxygenated habitat space are less clear. Variations in oxygenated vertical habitat space in the upper-ocean can alter interactions between predator and prey, as well as drive changes in the vulnerability of economically important tuna and other pelagic fish to surface fishing gear. Using in situ measurements, we show that ENSO is the primary driver of upper-ocean oxygen partial pressure (pO _2 ) variability on year-to-year time scales in the tropical Pacific. Mechanistically, these pO _2 variations are primarily caused by vertical shifts in thermocline depth, which alternately elevate and depress cold, hypoxic waters from the ocean interior depending on the ENSO phase and location. Transport-driven, isopycnal pO _2 variations within the thermocline also play an important but secondary role. In the western tropical Pacific, waters within the exclusive economic zones of Palau, Micronesia, Nauru, and the Marshall Islands undergo the greatest variations in oxygenated tuna vertical habitat extent: approximately 19.5 m, 23.9 m, 19.5 m, and 19.3 m, respectively, between El Niño and La Niña phases. Oxygen thus plays an important role in altering available tuna vertical habitat space between different phases of ENSO. |
| first_indexed | 2024-03-12T15:58:54Z |
| format | Article |
| id | doaj.art-ac27dbf44a50471fac22f108f06ce40d |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:58:54Z |
| publishDate | 2019-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-ac27dbf44a50471fac22f108f06ce40d2023-08-09T14:44:45ZengIOP PublishingEnvironmental Research Letters1748-93262019-01-0114606402010.1088/1748-9326/ab1c13ENSO drives near-surface oxygen and vertical habitat variability in the tropical PacificShirley Leung0https://orcid.org/0000-0002-6659-6420LuAnne Thompson1Michael J McPhaden2K A S Mislan3University of Washington , School of Oceanography, Seattle, WA, United States of AmericaUniversity of Washington , School of Oceanography, Seattle, WA, United States of AmericaPacific Marine Environmental Laboratory/NOAA, Seattle, WA, United States of AmericaUniversity of Washington , School of Oceanography, Seattle, WA, United States of AmericaEl Niño-Southern oscillation (ENSO) is the leading cause of sea surface temperature variability in the tropical Pacific with known impacts on tuna geographic range, but its effects on oxygen and available oxygenated habitat space are less clear. Variations in oxygenated vertical habitat space in the upper-ocean can alter interactions between predator and prey, as well as drive changes in the vulnerability of economically important tuna and other pelagic fish to surface fishing gear. Using in situ measurements, we show that ENSO is the primary driver of upper-ocean oxygen partial pressure (pO _2 ) variability on year-to-year time scales in the tropical Pacific. Mechanistically, these pO _2 variations are primarily caused by vertical shifts in thermocline depth, which alternately elevate and depress cold, hypoxic waters from the ocean interior depending on the ENSO phase and location. Transport-driven, isopycnal pO _2 variations within the thermocline also play an important but secondary role. In the western tropical Pacific, waters within the exclusive economic zones of Palau, Micronesia, Nauru, and the Marshall Islands undergo the greatest variations in oxygenated tuna vertical habitat extent: approximately 19.5 m, 23.9 m, 19.5 m, and 19.3 m, respectively, between El Niño and La Niña phases. Oxygen thus plays an important role in altering available tuna vertical habitat space between different phases of ENSO.https://doi.org/10.1088/1748-9326/ab1c13tropical Pacificoxygeninterannual variabilityENSOtunafisheries |
| spellingShingle | Shirley Leung LuAnne Thompson Michael J McPhaden K A S Mislan ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific Environmental Research Letters tropical Pacific oxygen interannual variability ENSO tuna fisheries |
| title | ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific |
| title_full | ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific |
| title_fullStr | ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific |
| title_full_unstemmed | ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific |
| title_short | ENSO drives near-surface oxygen and vertical habitat variability in the tropical Pacific |
| title_sort | enso drives near surface oxygen and vertical habitat variability in the tropical pacific |
| topic | tropical Pacific oxygen interannual variability ENSO tuna fisheries |
| url | https://doi.org/10.1088/1748-9326/ab1c13 |
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