Assessing aquatic biodiversity of zooplankton communities in an urban landscape

Aquatic ecosystems are common in urban environments. A solid understanding of aquatic species' distributions in urban habitats will both advance urban ecology and preserve biodiversity in cities. In particular, zooplankton are central components of aquatic food webs and their biodiversity patterns thus warrant further characterization and understanding. We examined sources of variation and biodiversity patterns of zooplankton communities across eighteen waterbodies in the urban landscape of Canada's large island city of Montreal. We report a total of 80 zooplankton taxa of which rotifers and cladocerans were major contributing taxa to biodiversity. We found a lack of agreement between contributions of individual waterbodies to rotifer and cladoceran beta diversity. Littoral vegetated zones proved to be important habitats for zooplankton biodiversity, contributing considerably to the species richness pool, often with a different species composition. Further variation in zooplankton community composition was attributable to local factors such as waterbody size, algal biomass and composition, and macroinvertebrate predators, but also to urban management practices such as waterbody draining during winter. We show that urban waterbodies can represent important reservoirs of biodiversity. Management practices favoring a large diversity of permanent and temporary habitats with littoral vegetated zones should be incorporated in urban design and conservation plans.