Biological and physical controls on multidecadal acidification in a eutrophic estuary

Estuaries support many ecologically and economically important resources that are especially vulnerable to ocean acidification from rising anthropogenic CO2. However, complex local processes in estuaries complicate and may disguise long-term pH trends. For example, terrestrial nutrient runoff and marine coastal upwelling may exacerbate pH variability and declines. We investigated eutrophication impacts on acidification in a central California estuary, Elkhorn Slough, which receives high nutrient loads from intensive surrounding agriculture and upwelling of the California Current System. We examined drivers of acidification including nutrients, ecosystem metabolism, and upwelling by modelling pH trends over 20 years using a Generalized Additive Mixed Model at four sites from the National Estuarine Research Reserve Systemwide Monitoring Program and collected additional water samples to calculate aragonite saturation. Our models revealed acidification trends over two decades which were mor..., , , # Biological and physical controls on multidecadal acidification in a eutrophic estuary

Carbonate Saturation State and Net Ecosystem Metabolism datasets from Elkhorn Slough estuary, CA. Including code used to generate these datasets, spectral analysis of decadal pH datasets and nutrients, and Generalized Additive Mixed Models (GAMMs) of the long-term trends and drivers of pH in the estuary.

## Description of the data and file structure

“Diel_water chemistry.csv”; Description: Water samples collected hourly for 24 hours each season at 6 sites in Elkhorn Slough, CA, using an ISCO autosampler and temperature and pH measured in situ with a HOBO pH logger; Headers: Site (Volunteer monitoring sites, “APC” Azevedo Central Pond, “AP” Azevedo Pond, “KP” Kirby Park, “BSE” Bennett Slough East, “JR” Jetty Road North, “SKL” Skipper’s Landing), Month (seasonal sampling in August, February, May, November), Hour (time of sample collection, Alkalinity_mgL (Alkalinity from sulfuric acid titration in...