A new report in the journal BioScience finds that it’s not uncommon for “sleeper populations” of invasive species to lie low in new environments for years or even decades. These small, self-sustaining populations of nonnative species can exist like this until a environmental trigger is tripped, and causes their numbers to explode.
Such is the case of the spiny water flea, discovered in Lake Mendota in 2009 by a group of undergraduates at the UW-Madison Center for Limnology. When researchers dug into samples from Lake Mendota and through old samples in the UW-Madison Zoological Museum, they discovered that the spiny water fleas had existed in the lake for a decade before their sudden population increase.
Understanding the environmental triggers that set a species on the path to invasion is crucial, says Mike Spear, lead author of the recently-published paper “The Invasion Ecology of Sleeper Populations: Prevalence, Persistence, and Abrupt Shifts,” now a postdoctoral researcher at the University of Illinois and Illinois Natural History Survey.
In this edition of the Perpetual Notion Machine, host Robert Monthey chatted with Spear about sleeper populations of nonnative species, trigger events, the spiny water flea, and what this all teaches us in a wider context of climate change.
Feature image: modification of Bythotrephes longimanus, courtesy J. Liebig, NOAA GLERL, 2001, via USGS.