Temporal evolution of zooplankton from 1898-1917 and 1966 onwards in the Northwestern Mediterranean Sea

The Observatoire of Villefranche sur Mer supports the daily sampling of zooplankton from 1898-1917 and 1966 onwards at a time series station located at the entrancy of the Bay of Villefranche sur Mer. Samples were collected by a vertical tow from bottom to surface (75-0 m), using a Juday-Bogorov net and Regent net. The sampling site is located at the mouth of the Bay over a bathymetry of 80m and is thus open to the Ligurian Sea. Zooplankton abundance was counted by specialist at OOV under microscopes. The different equipment which was used is the following: Regent net: 680µm of mesh, opening: 1m, length: 4m, opening: 0.785m²; Regent net: 700µm of mesh, opening 1m, length: 4m; Juday-Bogorov net: 380 µm of mesh, opening: 0.50, length: 1.80m; WP2: 220µm of mesh, opening: 0.25m². Method step description: For the siphonophores, since 1993, all data are transformed from a Regent Net to a Juday-Bogorov net with a coefficient *6 as described in original publication.