Zooplankton invasions in the early 21st century: a global survey of recent studies and recommendations for future research.

We present a comprehensive survey of the scientific literature pertaining to non-indigenous and invasive zooplankton published across the first decades of the twenty-first century (i.e., 2000-2018). We provide a concise summary of the manner in which the scientific community has allocated its efforts to this issue in recent decades, and to illuminate trends that emerge from the literature. Our search yielded 620 publications encompassing 139 invasive zooplankton species, with invasive zooplankton reported from every region of the planet-including the Arctic and Antarctic. Most taxa were reported in a small number of publications, with the majority being mentioned in only a single paper. In contrast, approximately half of the surveyed publications concerned just four species: , , , and . Our survey reveals strong geographic patterns among the literature, with most publications arising from economically developed western nations. We found that the majority of publications pertained to holoplanktonic organisms from freshwater habitats, especially from the North American Great Lakes. Based on these results, we present several recommendations for future research topics that may hold considerable opportunity for growth in our understanding of the invasion process.