Whales and Butterflies: The Migration Effect (9 of 9) (image) American Association for the Advancement of Science Share Print E-Mail Caption Roach (Rutilus rutilus) live in lakes and partly migrate into freshwater tributaries in winter. When most of the population migrates out of the lakes, zooplankton can thrive and control the abundance of phytoplankton, keeping the lake in a clear-water state. However, when most roach stay in the lakes over winter, they feed on zooplankton, reducing its abundance such that phytoplankton can become overabundant and force the lake into a turbid state. This image relates to a paper that appeared in the 4 April, 2014, issue of Science, published by AAAS. The paper, by Silke Bauer at Swiss Ornithological Institute in Sempach, Switzerland, and colleagues was titled, "Migratory Animals Couple Biodiversity and Ecosystem Functioning Worldwide." Credit [© Jakob Brodersen] Usage Restrictions Please cite the owner of the image when publishing. This image may be freely used by reporters as part of news coverage, with proper attribution. Non-reporters must contact Science for permission. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.