Dataset: salp_chloro
Deployment: OC370

Seawater was collected with Niskin bottles at several depths and filtered through both GFF filters and 2 µm pore glass fibre filters for analysis of Chlorophyll a and total phaeopigment. Immediately after water samples were filtered, filter pads were transferred into 6 ml of 90% acetone and the pigment was extracted in a dark refrigerator for 24 hours. Filter pads were removed and the test tubes centrifuged just prior to reading the fluorescence. Following the initial fluorescence reading, samples were acidified with ~0.2ml of HCl and reread. The fluorometer was calibrated using a spectrophotometer during each cruise using standard Chl-a derived from spinach. Chlorophyll-a and phaeopigments were calculated from standard equations (Strickland and Parsons 1972).