TY - JOUR
T1 - Coastal eutrophication drives acidification, oxygen loss, and ecosystem change in a major oceanic upwelling system
AU - Kessouri, Faycal
AU - McWilliams, James C.
AU - Bianchi, Daniele
AU - Sutula, Martha
AU - Renault, Lionel
AU - Deutsch, Curtis
AU - Feely, Richard A.
AU - McLaughlin, Karen
AU - Ho, Minna
AU - Howard, Evan M.
AU - Bednaršek, Nina
AU - Damien, Pierre
AU - Molemaker, Jeroen
AU - Weisberg, Stephen B.
N1 - Funding Information:
ACKNOWLEDGMENTS. This research was supported by National Oceanic and Atmospheric Administration (NOAA) Grants NA15NOS4780186 and NA15NOS4780191; California Ocean Protection Council Grant C0100400; and NSF Grant OCE-1419450. This work was supported by the NOAA under Ecosystem and Harmful Algal Bloom (ECOHAB) Award NA18NOS4780174. This is ECOHAB publication 980. Computational resources were provided by the Extreme Science and Engineering Discovery Environment through allocation TG-OCE170017; and by the supercomputer Hoffman2 at the University of California Los Angeles, at the Institute for Digital Research and Education. This is contribution No. 5157 from the NOAA Pacific Marine Environmental Laboratory. We thank Kristen Foley and Robin Dennis (USEPA National Exposure Research Laboratory) for providing the output from the Community Multiscale Air Quality Model, corrected over ocean surface with Tropical Rainfall Measuring Mission data.
Funding Information:
This research was supported by National Oceanic and Atmospheric Administration (NOAA) Grants NA15NOS4780186 and NA15NOS4780191; California Ocean Protection Council Grant C0100400; and NSF Grant OCE-1419450. This work was supported by the NOAA under Ecosystem and Harmful Algal Bloom (ECOHAB) Award NA18NOS4780174. This is ECOHAB publication 980. Computational resources were provided by the Extreme Science and Engineering Discovery Environment through allocation TG-OCE170017; and by the supercomputer Hoffman2 at the University of California Los Angeles, at the Institute for Digital Research and Education. This is contribution No. 5157 from the NOAA Pacific Marine Environmental Laboratory. We thank Kristen Foley and Robin Dennis (USEPA National Exposure Research Laboratory) for providing the output from the Community Multiscale Air Quality Model, corrected over ocean surface with Tropical Rainfall Measuring Mission data.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.
PY - 2021/5/25
Y1 - 2021/5/25
N2 - Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical–biogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight. The model is forced by large-scale climatic drivers and a reconstruction of local inputs via rivers, wastewater outfalls, and atmospheric deposition; it captures the fine scales of ocean circulation along the shelf; and it is validated against a large collection of physical and biogeochemical observations. Local land-based and atmospheric inputs, enhanced by anthropogenic sources, drive a 79% increase in phytoplankton biomass, a 23% increase in primary production, and a nearly 44% increase in subsurface respiration rates along the coast in summer, reshaping the biogeochemistry of the Southern California Bight. Seasonal reductions in subsurface oxygen, pH, and aragonite saturation state, by up to 50 mmol m−3, 0.09, and 0.47, respectively, rival or exceed the global open-ocean oxygen loss and acidification since the preindustrial period. The biological effects of these changes on local fisheries, proliferation of harmful algal blooms, water clarity, and submerged aquatic vegetation have yet to be fully explored.
AB - Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical–biogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight. The model is forced by large-scale climatic drivers and a reconstruction of local inputs via rivers, wastewater outfalls, and atmospheric deposition; it captures the fine scales of ocean circulation along the shelf; and it is validated against a large collection of physical and biogeochemical observations. Local land-based and atmospheric inputs, enhanced by anthropogenic sources, drive a 79% increase in phytoplankton biomass, a 23% increase in primary production, and a nearly 44% increase in subsurface respiration rates along the coast in summer, reshaping the biogeochemistry of the Southern California Bight. Seasonal reductions in subsurface oxygen, pH, and aragonite saturation state, by up to 50 mmol m−3, 0.09, and 0.47, respectively, rival or exceed the global open-ocean oxygen loss and acidification since the preindustrial period. The biological effects of these changes on local fisheries, proliferation of harmful algal blooms, water clarity, and submerged aquatic vegetation have yet to be fully explored.
KW - Acidification and oxygen loss
KW - Coastal eutrophication
KW - Human impacts
KW - Marine habitats
KW - Southern California upwelling ecosystem
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U2 - 10.1073/pnas.2018856118
DO - 10.1073/pnas.2018856118
M3 - Article
C2 - 34001604
AN - SCOPUS:85106363900
SN - 0027-8424
VL - 118
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 21
M1 - e2018856118
ER -