The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay
The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic–biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2018-05-01
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Series: | Biogeosciences |
Online Access: | https://www.biogeosciences.net/15/2649/2018/bg-15-2649-2018.pdf |
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author | I. D. Irby M. A. M. Friedrichs F. Da K. E. Hinson |
author_facet | I. D. Irby M. A. M. Friedrichs F. Da K. E. Hinson |
author_sort | I. D. Irby |
collection | DOAJ |
description | The Chesapeake Bay region is projected to experience changes in temperature,
sea level, and precipitation as a result of climate change. This research
uses an estuarine-watershed hydrodynamic–biogeochemical modeling system
along with projected mid-21st-century changes in temperature, freshwater
flow, and sea level rise to explore the impact climate change may have on
future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential
success of nutrient reductions in attaining mandated estuarine water quality
improvements. Results indicate that warming bay waters will decrease oxygen
solubility year-round, while also increasing oxygen utilization via
respiration and remineralization, primarily impacting bottom oxygen in the
spring. Rising sea level will increase estuarine circulation, reducing
residence time in bottom waters and increasing stratification. As a result,
oxygen concentrations in bottom waters are projected to increase, while
oxygen concentrations at mid-depths
(3 < DO < 5 mg L<sup>−1</sup>) will typically decrease.
Changes in precipitation are projected to deliver higher winter and spring
freshwater flow and nutrient loads, fueling increased primary production.
Together, these multiple climate impacts will lower DO throughout the
Chesapeake Bay and negatively impact progress towards meeting water quality
standards associated with the Chesapeake Bay Total Maximum Daily Load.
However, this research also shows that the potential impacts of climate
change will be significantly smaller than improvements in DO expected in
response to the required nutrient reductions, especially at the anoxic and
hypoxic levels. Overall, increased temperature exhibits the strongest control
on the change in future DO concentrations, primarily due to decreased
solubility, while sea level rise is expected to exert a small positive impact
and increased winter river flow is anticipated to exert a small negative
impact. |
first_indexed | 2024-12-20T07:59:02Z |
format | Article |
id | doaj.art-6608ea1168724b728093f5341a10b109 |
institution | Directory Open Access Journal |
issn | 1726-4170 1726-4189 |
language | English |
last_indexed | 2024-12-20T07:59:02Z |
publishDate | 2018-05-01 |
publisher | Copernicus Publications |
record_format | Article |
series | Biogeosciences |
spelling | doaj.art-6608ea1168724b728093f5341a10b1092022-12-21T19:47:34ZengCopernicus PublicationsBiogeosciences1726-41701726-41892018-05-01152649266810.5194/bg-15-2649-2018The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake BayI. D. Irby0M. A. M. Friedrichs1F. Da2K. E. Hinson3Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USAVirginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USAVirginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USAVirginia Institute of Marine Science, College of William & Mary, Gloucester Point, VA 23062, USAThe Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic–biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L<sup>−1</sup>) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.https://www.biogeosciences.net/15/2649/2018/bg-15-2649-2018.pdf |
spellingShingle | I. D. Irby M. A. M. Friedrichs F. Da K. E. Hinson The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay Biogeosciences |
title | The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay |
title_full | The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay |
title_fullStr | The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay |
title_full_unstemmed | The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay |
title_short | The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay |
title_sort | competing impacts of climate change and nutrient reductions on dissolved oxygen in chesapeake bay |
url | https://www.biogeosciences.net/15/2649/2018/bg-15-2649-2018.pdf |
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