Depth profile chlorophyll, macronutrient, trace metal, metal speciation, and carbon system data from FeOA project cruise SKQ202209S on the R/V Sikuliaq in the Northeast Pacific between June and July 2022

This dataset includes the concentrations of dissolved inorganic macronutrients (phosphate, nitrate plus nitrite (N+N), silicic acid, and nitrite), chlorophyll a and phaeophytin, dissolved trace metals (iron, manganese, nickel, zinc, copper), and labile dissolved nickel, as well as pH and total alkalinity measurements, from discrete depth profile samples collected on the FeOA cruise SKQ202209S on R/V Sikuliaq in the Northeast Pacific from June to July 2022.

This project investigates the effects of ocean acidification on the associations between iron and organic ligands in seawater and on iron bioavailability to marine phytoplankton communities. The project used a combination of shipboard incubation experiments and depth profiles to characterize iron speciation and cycling across coastal upwelling, oligotrophic open ocean, and iron-limited subarctic oceanographic regimes in the NE Pacific. Surface seawater was incubated at pH of 8.1, 7.6, and 7.1 with natural iron and with dissolved iron amendments in order to investigate interactions between pH and iron bioavailability across the different regimes. Understanding how pH influences iron and its relationship with ligands provides important information for assessing the impacts of ocean acidification on primary production and biogeochemical processes.