Documentation for Zooplankton data from gut evacuation experiments
AESOPS/APFZ Survey Cruises 1 (KIWI06) and 2 (KIWI08)

Live specimens were collected in vertical tows within the upper 200 m using a 1 m ring net of mesh size 280 m m with a 20 liter protected cod-end. Each tow was conducted at the same MOCNESS tow location soon after the MOCNESS was retrieved. The net was hauled at 10-15 m per min. After the net was retrieved, the cod-end was immediately transported to a dark temperature-controlled room to simulate the ocean water temperature (-1° C). The cod-end content was gently poured into a 20 liter bucket filled with GF/F filtered seawater at room temperature and then subdivided in 2 size classes using 2 large diameter sieves of 303 and 500 mm. Each sieve was successively transferred to a second and then a third bucket with GF/F filtered seawater to remove any traces of phytoplankton. Sequential samples were taken at short time intervals. Samples were immediately filtered by GF/F filters, stored in petri dishes and frozen at -80°C. Incubation and sampling were conducted up to 6 hrs after the net tow.

Samples were picked by species and stages under a dissecting stereoscope. The frozen GF/F filter was placed in a petri dish refrigerated by a cold plate. Nitrogen gas was blown into the sample to avoid excessive condensation on the samples and the scope. Chlorophyll and phaeopigment were extracted in methanol and measured using a Turner fluorometer. The number of animals in the analysis is typically 2-5 individuals of large copepods (1000-2000 m m), 5-10 for medium size copepods (500-1000 m m) and 10-50 for small copepods (200-500 mm).