Instrument: UV Spectrophotometer-Shimadzu

Dissolved organic carbon (DOC) concentration was measured using a Shimadzu TOC-5000A Analyzer:  Water samples were vacuum filtered (less than 25 kilopascal) using pre-combusted Whatman glass microfibre filters (GF/F).  The filtrate was stored in pre-combusted glass scintillation vials with Teflon closures and frozen at -20 degrees Celsius until analysis.  The Shimadzu TOC-5000A Analyzer uses high temperature catalytic oxidation followed by non-dispersive infrared analysis of the CO2 produced.  Samples were acidified to a pH less than 2 and sparged with air before they were analyzed for non-volatile organic carbon.  DOC values in 1996 were run from previously run nutrient samples. Starting February 2018, all stations were collected.  Prior to Feb. 2018 only NR 0, 30, 70, 100, 120, and 160 surface and bottom stations were measured.