The goal of the project is to examine the natural and anthropogenic factors that contribute to the formation of the hypoxic and corrosive conditions that have been observed along the Cascadia Margin and provide practical algorithms to estimate aragonite saturation from routine hydrographic data sets. The proposed work consists of field observational and algorithm-development components. The core field observations consist of detailed hydrographic and biogeochemical measurements along the Cascadia Margin using a combination of existing and new resources. Observations include detailed survey cruises to collect water column data throughout the study region, high-resolution sampling with a towed undulating instrument package in select locations during the upwelling season, and moored and underway surface CO2, O2, and pH time-series measurements. All field data collected from these sampling efforts will be used in the development of algorithms that allow prediction of the onset and evolution of corrosive conditions along the coastline. These algorithms will be tuned to the physical, chemical, and biological factors specific to each sub-region. This project strongly draws from and leverages collaborations that the PIs have with a wide network of researchers working along the west coast of North America.