Abundance and biomass of consistently identified taxa from net hauls at site L4 off Plymouth, UK from 1988-2023

Ongoing zooplankton research at the Plymouth Marine Laboratory has established a time series of zooplankton species since 1988 at L4, a coastal station off Plymouth, UK. Weekly samples are collected by vertical net hauls (WP2 net, mesh 200 µm; UNESCO 1968) from the sea floor (approximately 50 m) to the surface and stored in 4% buffered formalin. This dataset represents derived biomass data and measured abundance data from the taxonomic categories that have been consistently identified throughout the whole time series. While being a subset of the full species list, we have included all that contribute significantly to abundance and biomass. This has been done by pooling to lower taxonomic categories to achieve consistent enumeration (for instance, we have used here a single category for medusae even though they were identified to a greater taxonomic resolution after 2009). The higher taxonomic resolution version (albeit without consistent enumeration) can be found at https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/285d5ae7-934f-f7c4-e063-7086abc031fc/. Zooplankton abundance results presented are number m-3 and are mean values from two replicate hauls made on each sampling timepoint. Biomass results, presented are µg C m-3, are derived from taxonomic abundance measurements, and the method used is detailed in the documentation. It is encouraged that users of the data maintain contact with originators of the dataset to prevent misuse or misunderstanding of the data provided due to the complex nature and temporal coverage of the data provided.