Size-fractionated gut fluorescence from mesozooplankton collected aboard R/V Point Sur cruise BCS01 in the northern Gulf of Mexico from 2016-02-10 to 2016-02-12

This dataset contains size-fractionated gut fluorescence from mesozooplankton collected using a bongo net aboard R/V Point Sur cruise BCS01 in the northern Gulf of Mexico from 2016-02-10 to 2016-02-12. The samples were always taken from the left net, which had a 202-micrometer mesh size (if different, the mesh size used is indicated in the data table). Samples were transferred into a bucket immediately after retrieval and carbonated water was added to the sample to stop or avoid further 'net feeding' or regurgitation from individual zooplankton. Typically, each net sample was split into two aliquots using a Folsom Splitter aboard the ship. The 1/2 aliquot separated from the original sample was then split further into two subsamples: one was used to measure mesozooplankton gut fluorescence and the other was processed for the dry weight (reported separately). When samples were too thick, the initial sample was split into smaller aliquots (clearly indicated in the dataset). The corresponding aliquot was then size-fractionated into five classes using sieves with meshes measuring: 0.212, 0.5, 1, 2, and 4.75 mm. Filtered seawater was used during sample split and size fractionation. After fractionation, each sample was poured onto a GF filter (2.5 mm diameter) using a filtering system aboard the ship, rinsed with DI water, wrapped in aluminium foil and quick-frozen immediately after filtering by depositing the sample into liquid nitrogen. Before filtering, each sample was kept in the dark in an ice bath. Samples were processed following Strickland and Parsons (1968) spectrophotometric determination of phaeopigments protocol. These data will be used in combination with other mesozooplankton net data to study zooplankton processes in the river-dominated northern Gulf of Mexico. The cruise documentation was provided for the R/V Point Sur cruise BCS01, led by chief scientist Dr. Christian Briseño-Avena.