Working Group on Zooplankton Ecology (WGZE)

This report evaluates recent progress in understanding changes in zooplankton biomass, size structure, and community composition across the North Atlantic and adjacent seas, explores how these changes can be used to develop indicators of ecosystem status, and how emerging approaches such as trait-based analyses and imaging technologies can improve monitoring and interpretation of ecosystem change.</p><p dir="ltr">Across the North Atlantic, zooplankton biomass shows a consistent decline during the productive summer months, driven mainly by reductions in dominant crustacean groups.

This decrease is only partly offset by increases in other taxa outside the growing season. These changes suggest a reduction in both the quantity and quality of prey available to higher trophic levels during periods of peak biological demand, with potential implications for food web structure and ecosystem functioning. Analyses of size structure indicate a decline in larger plankton components, pointing to reduced efficiency of energy transfer through pelagic systems.