Dataset: zooplankton counts and abundances

Zooplankton samples were collected in Trondheimsfjord near Trondheim, Norway from 3 May to 11 June 2012 using a Sea-Gear 75-cm diameter ring net equipped with 150 micron mesh net and a cod end.  Oblique tows were conducted over the upper ~50 m for nearly all tows.  A close-open-close mechanism was used to collect zooplankton samples with the same net between roughly 250 and 350 m on three occasions.  The volume filtered by the net was estimated using a General Oceanics flowmeter suspended in the center of the net mouth, and sample depths were measured using a SeaBird SBE39 depth-temperature recorder.  Zooplankton samples were held on ice during transport back to the NTNU/SINTEF laboratory in Trondheim.  Samples were live sorted to remove some late-stage Calanus finmarchicus, and then preserved in 5% buffered formalin.  A small aliquot (subsample) of the bulk sample was removed and all taxa contained therein were enumerated.  Species- or taxon-specific abundance of zooplankton was estimated from the raw counts, the subsample volume, sample volume, and the volume filtered by the net.