Dataset: Sediment trap chlorophyll and phaeopigment flux

Data comes from VERTEX-style, surface-tethered, drifting sediment trap deployments. Particle interceptor tubes were deployed on cross-pieces with 16 tubes attached. Tubes were deployed with a dense formaldehyde brine created by adding NaCl and formaldehyde to filtered seawater. After recovery, overlying seawater was removed from each cruise by gentle suction. Tubes were then gravity filtered through a 200-micron nitex mesh filter, and the 200-micron filters were carefully analyzed under a stereomicroscope and all metazoan zooplankton "swimmers" were removed from the sample. Material remaining on the 200-micron filters (i.e., sinking material) was then imaged with a macrophotography rig and subsequently rinsed back into the original sample tube (i.e., re-combined with the <200-micron sinking material). Samples were then separated and filtered onto different types of filters for a suite of different analyses including: particulate organic carbon flux, particulate nitrogen flux, carbon and nitrogen isotopes, chlorophyll a and phaeopigment flux, microscopy, genetic analyses, and 234Th flux.

Triplicate 50-mL subsamples for Chlorophyll a and phaeopigments were filtered onto GF/F filters under low vacuum pressure. Samples were then placed in glass vials and frozen at -80C. They were later thawed out, and 7-mL of acetone was added. Samples were placed in a -20C freezer for 24 hours. Samples were then analyzed on a 10-AU fluorometer for Chl a and phaeopigments following Strickland and Parsons (1972).