Bottle chemistry data from hydrothermal vents sampled by CTD rosette during R/V Atlantis cruise AT37-12 in April and May 2017

The Eastern Tropical North Pacific (ETNP), like the other marine oxygen deficient zones (ODZs), is characterized by an anoxic water column, nitrite accumulation at the anoxic core, and fixed nitrogen loss via nitrite reduction to N2O and N2 gases. Here, we constrain the relative contribution of biogeochemical processes to observable features such as the secondary nitrite maximum (SNM) and local pH maximum by simultaneous measurement of inorganic nitrogen and carbon species. Bottle chemistry data for discrete depths were sampled by CTD rosette from hydrothermal vents in the Eastern Tropical North Pacific during R/V Atlantis cruise AT37-12 in April and May 2017.