U.S. Army Corps of Engineers Sacramento District senior fisheries biologist Robert Chase displays a Passive Integrated Transponder that used to track the behavior of North American green sturgeons that migrate along the Sacramento River every three to five years. USACE fisheries biologists have inserted telemetric tags in 85 green sturgeons over the past four years, which is helping them gather behavioral data on the ancient fish species. The data is then analyzed to determine the degree of impacts USACE civil works projects may or may not have on the species that since 2006 has been listed as threatened under the Endangered Species Act. (U.S. Army photo by Ken Wright)