Spatial and Temporal pH Variability in a California Estuary During the Winter Wet Season

Anthropogenic stressors such as increased atmospheric carbon dioxide (CO2) are impacting carbonate chemistry in the global ocean by decreasing the pH, a process known as ocean acidification. (Doney et al., 2009; Feely et al., 2009; Orr et al., 2005). The direct impact of anthropogenic CO2 emissions...

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Bibliographic Details
Main Author: Schmid, Garrett S
Format: Text
Language:unknown
Published: DigitalCommons@CalPoly 2020
Subjects:
pH
Online Access:https://digitalcommons.calpoly.edu/biosp/40
https://digitalcommons.calpoly.edu/context/biosp/article/1043/viewcontent/Spatial_and_Temporal_pH_Variability_in_a_California_Estuary_During_the_Winter_Wet_Season.pdf
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Summary:Anthropogenic stressors such as increased atmospheric carbon dioxide (CO2) are impacting carbonate chemistry in the global ocean by decreasing the pH, a process known as ocean acidification. (Doney et al., 2009; Feely et al., 2009; Orr et al., 2005). The direct impact of anthropogenic CO2 emissions on the nearshore coastal ocean and estuarine environments is largely uncertain (Duarte et al., 2013). In particular, estuaries are highly dynamic and productive biogeochemical systems (Bauer et al. 2013; Wang et al. 2016); however, information regarding the spatial and temporal variations of carbonate chemistry within these environments is limited (Cai et al. 2011; Hofmann et al. 2011; Waldbusser et al. 2011). The variability of the carbonate chemistry in estuaries is driven by both physical and biological processes (Flecha et al., 2015; Joesoef et al., 2017). Physical processes are largely governed by the interplay between freshwater discharge and tidal forcing (and mixing). Spatially, the back of an estuary (i.e, the head) is typically more strongly influenced by riverine input while the front of an estuary (i.e., the mouth) is regulated by tidal forcing and oceanic inputs. Biological processes influence the carbonate chemistry predominantly via primary production, microbial respiration (Waldbusser & Salisbury 2014), precipitation (calcification) and dissolution of calcium carbonate (Wolf-Gladrow et al., 2007). Primary production, from autotrophic organisms such as phytoplankton, macroalgae, and eelgrass, can increase seawater pH and dissolved oxygen (DO) of the surrounding water through the consumption of CO2 and the release of oxygen (O2) (Middelboe and Hansen 2007). Marine respiration decreases pH and DO through the consumption of O2 and the release of CO2. Seasonally, low-inflow estuaries (LIEs) are a class of estuaries typically found in Mediterranean climates whereby freshwater input is minimal during the summer “dry” season and increases during the winter “wet” season (Largier, 2010; Walter et al., 2018). ...