Data from: A compendium of geochemical information from the Saanich Inlet water column

Marine oxygen minimum zones (OMZs) are widespread and naturally occurring water column features that constitute ~7% of global ocean volume, but contribute disproportionately to biogeochemical cycling of carbon, nitrogen and climate active trace gases such as nitrous oxide and methane. Climate change compounded by other human activities is causing OMZ expansion. While microbial communities are the primary engines driving biogeochemical cycles in OMZs, our current understanding of microbial community metabolism is hindered by a lack of time-series observations charting responses to changing water column oxygen-deficiency. Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island British Columbia is a model ecosystem for monitoring microbial community structure, function and dynamics in relation to changing levels of water column oxygen-deficiency extensible to coastal and open ocean OMZs. Here, we present nine years of monthly time series observations in Saanich Inlet encompassing water column chemistry and environmental sequence information. This compendium provides a unique ecological and biogeochemical framework for comparative community analysis and modelling efforts in OMZs throughout the global ocean