Mesozooplankton species composition and abundance

Mesozooplankton was sampled vertically with a Multinet (180 µm mesh size, 0.25 m**2 mouth opening, Hydro-Bios, Kiel, Germany). Hauling speed was 0.5 m/s. Samples were preserved in a solution of 80% seawater and 20% fixation agent (75% formaldehyde buffered with hexamine, 25% anti-bactericide propandiol), resulting in a final concentration of 4% formaline.