Mesozooplankton (mesoZP) per capita mass, elemental composition and stable N isotopes during the mesocosm experiment in the Canary Islands in autumn 2018. Depth-integrated (0-14 m) plankton nets were taken over the course of 38 days. Metazoan zooplankton were split into three size fractions (55-200, 200-500 and >500 µm), picked into tin cups in groups and C, N and δ15N measured in an element analyser coupled to a mass spectrometer. Particulate organic matter (>0.7µm) was also measured for a comparison of C/N between the bottom of the food web and mesoZP grazers. The upwelling treatment started on day 4. Methodological details in Ortiz et al. (2022) (doi:10.3389/fmars.2021.743105), Baumann et al. (2021) (doi:10.3389/fmars.2021.742142) and Goldenberg et al. (under review).