Variable coastal hypoxia exposure and drivers across the southern California Current

Natalie H N Low^{1

2}, Fiorenza Micheli^{3

4}, Juan Domingo Aguilar⁵, Daniel Romero Arce⁶, Charles A Boch⁷, Juan Carlos Bonilla⁸, Miguel Ángel Bracamontes⁹, Giulio De Leo³, Eduardo Diaz¹⁰, Eduardo Enríquez¹¹, Arturo Hernandez¹⁰, Ramón Martinez¹², Ramon Mendoza¹³, Claudia Miranda¹⁴, Stephen Monismith¹⁵, Mario Ramade¹⁶, Laura Rogers-Bennett^{17

18}, Alfonso Romero¹⁰, Carmina Salinas¹⁹, Alexandra E Smith^{3

20}, Jorge Torre¹⁰, Gustavo Villavicencio²¹, C Brock Woodson²²

Affiliations

¹ Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA. nlow@mbari.org.
² Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA. nlow@mbari.org.
³ Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
⁴ Stanford Center for Ocean Solutions, Stanford University, Pacific Grove, CA, USA.
⁵ Sociedad Cooperativa de Producción Pesquera Progreso, La Bocana, Baja California Sur, México.
⁶ Sociedad Cooperativa de Producción Pesquera Pescadores Nacionales de Abulón, Isla Cedros, Baja California Sur, México.
⁷ Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, San Diego, CA, USA.
⁸ Sociedad Cooperativa de Producción Pesquera La Purísima, Bahía Tortugas, Baja California Sur, México.
⁹ Sociedad Cooperativa de Producción Pesquera Ensenada, El Rosario, Baja California, México.
¹⁰ Comunidad y Biodiversidad, La Paz, Baja California Sur, México.
¹¹ Sociedad Cooperativa de Producción Pesquera Punta Abreojos, Punta Abreojos, Baja California Sur, México.
¹² Sociedad Cooperativa de Producción Pesquera Buzos y Pescadores de la Baja California, Isla Natividad, Baja California Sur, México.
¹³ Sociedad Cooperativa de Producción Pesquera Bahía Tortugas, Bahía Tortugas, Baja California Sur, México.
¹⁴ Sociedad Cooperativa de Producción Pesquera California San Ignacio, Bahía Asunción, Baja California Sur, México.
¹⁵ Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, 94305, USA.
¹⁶ Federación Regional de Sociedades Cooperativas de la Industria Pesquera Baja California, Ensenada, Baja California, México.
¹⁷ Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California Davis, Davis, CA, USA.
¹⁸ California Department of Fish and Wildlife, Bodega Marine Laboratory, Bodega Bay, CA, USA.
¹⁹ Sociedad Cooperativa de Producción Pesquera Emancipación, Bahía Tortugas, Baja California Sur, México.
²⁰ Scoot Science, Santa Cruz, CA, USA.
²¹ Sociedad Cooperativa de Producción Pesquera Leyes de Reforma, Bahía Asunción, Baja California Sur, México.
²² COBIA Lab, University of Georgia, Athens, GA, USA.

PMID: 34035327
PMCID: PMC8149850
DOI: 10.1038/s41598-021-89928-4

Variable coastal hypoxia exposure and drivers across the southern California Current

Natalie H N Low et al. Sci Rep. 2021.

. 2021 May 25;11(1):10929.

doi: 10.1038/s41598-021-89928-4.

Authors

Affiliations

¹ Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA. nlow@mbari.org.
² Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA. nlow@mbari.org.
³ Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
⁴ Stanford Center for Ocean Solutions, Stanford University, Pacific Grove, CA, USA.
⁵ Sociedad Cooperativa de Producción Pesquera Progreso, La Bocana, Baja California Sur, México.
⁶ Sociedad Cooperativa de Producción Pesquera Pescadores Nacionales de Abulón, Isla Cedros, Baja California Sur, México.
⁷ Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, San Diego, CA, USA.
⁸ Sociedad Cooperativa de Producción Pesquera La Purísima, Bahía Tortugas, Baja California Sur, México.
⁹ Sociedad Cooperativa de Producción Pesquera Ensenada, El Rosario, Baja California, México.
¹⁰ Comunidad y Biodiversidad, La Paz, Baja California Sur, México.
¹¹ Sociedad Cooperativa de Producción Pesquera Punta Abreojos, Punta Abreojos, Baja California Sur, México.
¹² Sociedad Cooperativa de Producción Pesquera Buzos y Pescadores de la Baja California, Isla Natividad, Baja California Sur, México.
¹³ Sociedad Cooperativa de Producción Pesquera Bahía Tortugas, Bahía Tortugas, Baja California Sur, México.
¹⁴ Sociedad Cooperativa de Producción Pesquera California San Ignacio, Bahía Asunción, Baja California Sur, México.
¹⁵ Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, 94305, USA.
¹⁶ Federación Regional de Sociedades Cooperativas de la Industria Pesquera Baja California, Ensenada, Baja California, México.
¹⁷ Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California Davis, Davis, CA, USA.
¹⁸ California Department of Fish and Wildlife, Bodega Marine Laboratory, Bodega Bay, CA, USA.
¹⁹ Sociedad Cooperativa de Producción Pesquera Emancipación, Bahía Tortugas, Baja California Sur, México.
²⁰ Scoot Science, Santa Cruz, CA, USA.
²¹ Sociedad Cooperativa de Producción Pesquera Leyes de Reforma, Bahía Asunción, Baja California Sur, México.
²² COBIA Lab, University of Georgia, Athens, GA, USA.

PMID: 34035327
PMCID: PMC8149850
DOI: 10.1038/s41598-021-89928-4

Abstract

Declining oxygen is one of the most drastic changes in the ocean, and this trend is expected to worsen under future climate change scenarios. Spatial variability in dissolved oxygen dynamics and hypoxia exposures can drive differences in vulnerabilities of coastal ecosystems and resources, but documentation of variability at regional scales is rare in open-coast systems. Using a regional collaborative network of dissolved oxygen and temperature sensors maintained by scientists and fishing cooperatives from California, USA, and Baja California, Mexico, we characterize spatial and temporal variability in dissolved oxygen and seawater temperature dynamics in kelp forest ecosystems across 13° of latitude in the productive California Current upwelling system. We find distinct latitudinal patterns of hypoxia exposure and evidence for upwelling and respiration as regional drivers of oxygen dynamics, as well as more localized effects. This regional and small-scale spatial variability in dissolved oxygen dynamics supports the use of adaptive management at local scales, and highlights the value of collaborative, large-scale coastal monitoring networks for informing effective adaptation strategies for coastal communities and fisheries in a changing climate.

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Conflict of interest statement

The authors declare no competing interests.

Figures

**Figure 1**
Temperature (black line) and dissolved oxygen (blue line) dynamics at 18 coastal sites in the southern California Current, over the 1-year period between October 2017 and September 2018. The dashed line represents the 2 mg/L threshold of hypoxia.

**Figure 2**
Summary metrics of dissolved oxygen (DO) variability at 18 sites in the southern California Current between October 2017 and September 2018: (a) minimum DO recorded during the year; (b) coefficient of variation in DO; (c) mean rate of change in DO; (d) total number of exposures to hypoxic conditions (≤ 2 mg/L); (e) mean duration of exposure to hypoxia; (f) mean return time between exposures to hypoxia. Sites are arranged by latitude from north to south. The dashed line indicates the 2 mg/L threshold for hypoxia.

**Figure 3**
Monthly correlation values between temperature and dissolved oxygen for each site. The dashed line represents a correlation coefficient of 0.7, which is a significant positive correlation.

**Figure 4**
Proportion of total hypoxic (< 2 mg/L dissolved oxygen) events in each month, for each site.

See this image and copyright information in PMC

References

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1. Laffoley D, Baxter JM, editors. Ocean deoxygenation: Everyone’s problem. Causes, impacts, consequences and solutions. IUCN, International Union for Conservation of Nature; 2019.
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Variable coastal hypoxia exposure and drivers across the southern California Current

Affiliations

Variable coastal hypoxia exposure and drivers across the southern California Current

Authors

Affiliations

Abstract

Conflict of interest statement

Figures

References

Publication types

LinkOut - more resources

Full Text Sources

Other Literature Sources