We wish to thank the many partners and supporters of the NSERC LakePulse Network, as well as the Natural Sciences and Engineering Research Council (NSERC, Canada) for funding the project and BEB in the form of a Discovery Grant. IGE also acknowledges support from the Canada Research Chair program. We thank the Group for Interuniversity Research in Limnology (Groupe de recherche interuniversitaire) and their funders, the Fonds de recherche -nature et technologie (FRQNT, Québec) and the Faculty of Science at the University of Québec at Montréal for PhD stipend and scholarship support to CP. We thank the field teams who put in a great effort to sample the lakes, and landowners, including several First Nations, who welcomed our sampling.We would like to thank BSA environmental services for the zooplankton identification.Thanks to all the students, post-doctoral fellows and research professionals who contributed to the project; particularly Katherine Velghe, Marie-Pierre Varin, Maxime Fradette and Jelena Juric for their significant contributions to data generation and analyses, field coordination and database management. Finally, we thank Yannick Huot for directing the LakePulse project. BIOSKETCH: CINDY PAQUETTE is a PhD student part of the NSERC LakePulse network undertaking her studies in the Department of Biology at UQAM, co-supervised by I.G.-E. (McGill University) and B.E.B. TITLE: Zooplankton biogeography across temperate to subarctic regions: taxonomic and functional perspectives RUNNING TITLE: Canadian zooplankton biogeography ABSTRACT Aim: We examined variation in crustacean zooplankton taxonomic and functional composition and diversity across Canadian lakes. In addition to α-diversity patterns, we also explore mechanisms behind β-diversity spatial variation, using taxonomic and functional metrics. Location: Canada.

Aim: While it is now well accepted that human activities are having pronounced effects on natural ecosystems, regional variation in the rate and magnitude of various human impacts is unclear. Moreover, the effects of land use change on natural aquatic communities have only relatively recently begun to be explored. Our goal was to understand how and where assemblages of a central food web component of freshwater lakes have changed over the course of industrialization in relation to land use.Location: Canada.

Canada is home to more lakes than any other nation, but there is a fragmented and limited understanding of the ecological status of these water bodies. Zooplankton are excellent bioindicators of lake health, given their central food web position. To date, many studies have investigated the effect of individual stressors on zooplankton communities, mediated through changes in water quality (e.g., macronutrients, temperature, or chemicals). Increasingly, stressors act simultaneously in lakes, often over extended periods of time. As part of the NSERC Canadian Lake Pulse Network project, pelagic zooplankton were sampled in 624 lakes across Canada, spanning six continental drainage basins. We evaluated the effect of 40+ environmental variables on zooplankton diversity and community composition, considering both taxonomic and functional approaches. We also tested specific hypotheses on the relationships between zooplankton communities and environmental conditions, including eutrophication, calcium, chloride, and fish predation. We found that lake morphometry variables were among the most important predictors of zooplankton diversity, while water quality metrics were more critical in explaining variation in community composition. Our results also reveal significant heterogeneity across Canada, with contrasting effects of environmental drivers among continental watersheds, highlighting that response models cannot be assumed to apply universally.