Mesozooplankton, North Sea and Skagerrak 2006–2024

This dataset provides data on mesozooplankton from the northern North Sea and Skagerrak 2005-2024, collected and analyzed by the Plankton Research Group at the Institute of Marine Research (IMR), Norway. The dataset includes information on taxa (species or higher taxonomic levels), life stages, and abundances of mesozooplankton 2005-2024. Three main transects (“Utsira–W”, “Hanstholm–Aberdeen”, and “Torungen–Hirtshals”) have been sampled approximately four times per year, in addition to larger-scale ecosystem surveys mainly conducted in spring (April to early May). Zooplankton data are also provided from three monitoring stations located along the Norwegian Skagerrak coast, sampled 1–2 times per month. Sampling has been conducted at predefined stations using a standard WP2 net (0.56 m opening diameter, 180 μm mesh size), towed vertically from near-bottom to the surface. Samples were preserved in formaldehyde and analyzed using a stereomicroscope for enumeration and species identification. Abundances are expressed as individuals per cubic meter (N/m³). The IMR North Sea monitoring activity is part of the IMR project “Climate and Plankton in the North Sea and Skagerrak,” funded by the Ministry of Trade, Industry and Fisheries. The IMR coastal monitoring has been funded by the IMR Coastal Research Programme and the Norwegian Environment Agency. This dataset was submitted to OSPAR via ICES DOME for inclusion in the OSPAR Intermediate Assessment 2029 (IA 2029) in OSPAR Region II (Greater North Sea).