Mesozooplankton abundance during Ana Maria Gayoso cruise in the South western Atlantic during late spring 2021

The abundance of mesozooplankton was assessed in the Southwestern Atlantic (SWA, 36-48ºS, 64-54ºW) during late spring (November 2021) on the Ana Maria Gayoso oceanographic cruise aboard the vessel Bernardo Houssay. The study covered three regions: the outer Patagonian shelf, the slope waters in the core of the Malvinas Current, and the adjacent open ocean in the Argentine Basin. Mesozooplankton samples were obtained from vertical tows equipped with a mechanical flowmeter. Organisms were identified and counted under a binocular stereomicroscope, up to the species level when possible. Biomass was estimated from literature only for copepods and euphausiids using previously established regressions to convert body length to wet weight biomass.