Chapman and Patrick Kocovsky of the USGS' Lake Erie Biological Station analyzed temperatures in Lake Erie as well as temperatures, river length and velocity -- three factors considered critical for young carp to survive -- in Lake Erie's tributaries. Comparing their measurements to data from Russian and Chinese lakes and rivers inhabited by the carp, they found temperatures in Erie's western basin and the Maumee tributary were warm enough each year to ensure rapid growth and maturing of both silver and bighead carp.