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Research article - Peer-reviewed, 2022

Gelatinous macrozooplankton diversity and distribution dataset for the North Sea and Skagerrak/Kattegat during January-February 2021

Kohler, Louise G.; Huwer, Bastian; Pujolar, Jose Martin; Werner, Malin; Wikstrom, Karolina; Wernbo, Anders; Ovegard, Maria; Jaspers, Cornelia


This data article includes a qualitative and quantitative description of the gelatinous macrozooplankton community of the North Sea during January-February 2021. Sampling was conducted during the 1 st quarter International Bottom Trawl Survey (IBTS) on board the Danish R/V DANA (DTU Aqua Denmark) and the Swedish R/V Svea (SLU Sweden), as part of the ichthyoplankton investigation during night-time. A total of 147 stations were investigated in the western, central and eastern North Sea as well as the Skagerrak and Kattegat. Sampling was conducted with a 13 m long Midwater Ring Net (MIK net, O 2 m, mesh size 1.6 mm, cod end with smaller mesh size of 500 mu m), equipped with a flow meter. The MIK net was deployed in double oblique hauls from the surface to c. 5 m above the sea floor [1 , 2] . Samples were visually analysed unpreserved on a light table and/or with a stereomicroscope or magnifying lamp within 2 hours after catch. A total of 13,510 individuals were counted/sized. Twelve gelatinous macrozooplankton species or genera were encountered, namely the hydrozoan Aequorea vitrina, Aglantha digitale, Clytia spp., Leuckartiara octona, Tima bairdii, Muggiaea atlantica ; the scyphozoans Cyanea capillata and Cyanea lamarckii and the ctenophores Beroe spp., Bolinopsis infundibulum, Mnemiopsis leidyi, Pleurobrachia pileus . Abundance data are presented on a volume specific (m -3 ) and area specific (m -2 ) basis. Size data have been used to estimate wet weights based on published length-weight regressions (see Table 1). For the groups i) hydrozoan jellyfish, ii) scyphozoan jellyfish, iii) ctenophores, as well as iv) grouped gelatinous macrozooplankton, spatial weight specific distribution patterns are presented. This unpublished dataset contributes baseline information about the gelatinous macrozooplankton diversity and its specific distribution patterns in the extended North Sea area during winter (January-February) 2021. These data can be an important contribution to address global change impacts on marine systems, especially considering gelatinous macrozooplankton abundance changes in relation to anthropogenic stressors.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license


IBTS; Jellyfish; Comb jelly; gelatinous zooplankton

Published in

Data in Brief
2022, volume: 44, article number: 108493

Authors' information

Kohler, Louise G.
Technical University of Denmark
Huwer, Bastian
Technical University of Denmark
Pujolar, Jose Martin
Technical University of Denmark
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Jaspers, Cornelia
Technical University of Denmark

Associated SLU-program

Coastal and sea areas

Sustainable Development Goals

SDG14 Life below water

UKÄ Subject classification


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