Dataset: Nutrients and dissolved organic carbon bottle data from R/V Rachel Carson RC0078 cruise in the Salish Sea in June 2022

Seawater for nutrients and dissolved organic carbon (DOC) analyses were typically collected from the CTD rosette in triplicate from different rosette bottles from two or three depths per cast.

For dissolved organic carbon (DOC) concentration measurements, seawater was collected directly from CTD bottles into a filtration apparatus consisting of a glass syringe connected to a filter unit loaded with 25 mm carbon-cleaned GF/F filter  (combusted at 450 °C for 4 hours.) 2–30 mL of seawater was filtered into a 40 mL glass TOC “EPA” pre-chilled glass vials (about ½ to 3/4 full). Vial moisture/condensation was wiped off of the outside of the vial and immediately placed in the freezer (upright). Samples were shipped frozen to the University of Washington Marine Chemistry Laboratory for analysis.

Seawater samples for nutrient concentration analysis (phosphate, silicate, nitrate, nitrite, and ammonium) were collected from CTD bottles into 60 ml plastic syringes loaded with a surfactant-free cellulose membrane (25 mm, 0.45 micron pore size, Nalgene). Syringes and 60 ml HDPE sample collection bottles were rinsed twice with sample water. About 45-50 ml of seawater was filtered into the collection bottles after rinsing again with 5 mL of filtered water. Samples were frozen for storage.