Double oblique zooplankton net tows from 200 m water depth to the sea-surface were carried out using a 0.7 m diameter Bongo frame with paired 200 µm mesh nets, a General Oceanics Flow meter affixed to each net to measure the volume of water filtered, and a temperature-depth recorder. Tows were conducted at least twice daily (day and night), with one additional day per cycle of sampling every 2-3 hours for further studies of diel patterns. A quantitative subset of salp specimens were identified to species using keys (Foxton 1965, doi:10.1017/S0025315400016519; Bone 1998), classified into oozooid or blastozooid stage, and measured for total length and corrected to oral to atrial (OAL). For plots and calculations, Salpa thompsoni lengths were divided into 5 mm bins, and abundance was calculated for each size bin.

This study was funded by the Ministry for Business, Innovation and Employment (MBIE) of New Zealand, NIWA core programmes Coast and Oceans Food Webs (COES- COES1901) and Ocean Flows (COOF-COOF1902), the Royal Society of New Zealand Marsden Fast-track award to Moira Décima, and NSF award #OCE-1756610 to Michael R. Stukel and Karen E. Selph.