In March 2015, transects of CTD casts were run on the Chinese RV Haiyang 4 in the northern South China Sea parallel and perpendicular to the coastline and the shelf break. During casts, go-flo bottles were used to collect water samples from the surface to bottom depth. Water samples were analyzed for dissolved nutrients (NO2, NO3, PO4, NH4, SiO4) and particulate organic matter (SPM, POC, PN, CHLa, d13C). Salinity and temperature were recorded by CTD. Metadata is comprised of cast number, bottle depth, data, cast start time (UTC), station name, latitude, longitude, and bottom depth.