Impacts of Sea‐Level Rise on Hypoxia and Phytoplankton Production in Chesapeake Bay: Model Prediction and Assessment

Details

• Journal Title:
  JAWRA Journal of the American Water Resources Association
• Personal Author:
  Cai, Xun ; Shen, Jian ; Zhang, Yinglong J. ; Qin, Qubin ; Wang, Zhengui ; Wang, Harry
• NOAA Program & Office:
  NOS (National Ocean Service)
• Description:
  In this study, the influence of sea‐level rise (SLR) on seasonal hypoxia and phytoplankton production in Chesapeake Bay is investigated using a 3D unstructured grid model. Three SLR scenarios (0.17, 0.5, and 1.0 m) were conducted from 1991 to 1995. Results show that the summer hypoxic volume (HV) increases about 2%, 8%, and 16%, respectively, for these three scenarios, compared with Base Scenario. The contributions of physical and biological processes on the increase in the HV were analyzed. With the projected SLR, enhanced gravitational circulation transports more oxygen‐rich water in the bottom layer from the mouth. However, the pycnocline moves upwards along with increasing water depth, which largely prolongs the time for dissolved oxygen (DO) to be transported to the bottom. The altered physical processes contribute greatly to a larger HV bay‐wide. Besides, SLR increases the whole Bay phytoplankton production, with a larger increase in shallow areas (e.g., 53% in areas with depth <1 m under SLR of 0.5 m). Enhanced light availability is suggested to be the major driver of blooming phytoplankton under SLR in shallow areas. While increased DO production over the euphotic zone is mostly released to the atmosphere and transported downstream, the increase in settled organic matter greatly promotes DO consumption in the water column. The increased respiration is another major cause of the HV increase besides the physical contributions.
• Keywords:
  Earth-Surface Processes Ecology Water Science And Technology Water Science And Technology Water Science And Technology
• Source:
  JAWRA Journal of the American Water Resources Association, 58(6), 922-939
• DOI:
  https://doi.org/10.1111/1752-1688.12921
• ISSN:
  1093-474X ; 1752-1688
• Format:
  PDF
• Publisher:
  Wiley
• Document Type:
  Journal Article
• Funding:
  Grant no. NA20NOS4200205
• Rights Information:
  Accepted Manuscript
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:0afe7ba7bae8c640caf76414b866f9e7f4a83ae551f8fb794d3e3cfa08a0df07
• Download URL:
  https://repository.library.noaa.gov/view/noaa/57040/noaa_57040_DS1.pdf
• File Type:
  [PDF - 1.69 MB ]