Tracking Aquatic Invaders IMAGE LICENSED BY INGRAM PUBLISHING Autonomous Robots for Monitoring Invasive Fish By Pratap Tokekar, Elliot Branson, Joshua Vander Hook, and Volkan Isler C arp is a highly invasive bottom-feeding fish that pollutes and dominates lakes by releasing harmful nutrients. Recently, biologists started studying the behavior of carp by tagging the fish with radio emitters. The biologists search for and localize the radio-tagged fish manually using a global positioning system (GPS) and a directional antenna. We are developing a novel robotic sensor system in which human Digital Object Identifier 10.1109/MRA.2012.2220506 Date of publication: 11 September 2013 1070-9932/13/$31.00©2013IEEE effort is replaced by autonomous robots capable of finding and tracking tagged carp. In this article, we report the current state of our system. We present a new coverage algorithm for finding tagged fish and active localization algorithms for precisely localizing them. In addition to theoretical analysis and simulation results, we report results from field experiments. Robotic Sensor System Invasive fish, such as the common carp, pose a major threat to the ecological integrity of freshwater ecosystems around the world. Presently, these fish are controlled with SEPTEMBER 2013 * IEEE ROBOTICS & AUTOMATION MAGAZINE * 33