Female pallid sturgeon PLS07-001 was initially implanted with telemetry devices in the spring of 2007 near river mile 670, about 35 miles upstream from Omaha, NE. Five years of her travels are shown on the graph below. In the spring of 2007, a lack of black eggs showed that she was not in reproductive condition. During the fall of 2007, she moved approximately 100 miles upstream from her initial capture location and in May 2008 she was found less than 30 miles downstream from Gavins Point Dam. Unfortunately, she evaded our recapture efforts to confirm that her movements were likely a spawning migration. When biologists were able to recapture her in July 2008, surgical examination of her ovaries revealed that she had spawned earlier that spring, likely not too far from where she was found in May near Gavins Point Dam.
During the fall of 2010, PLS07-001 was again recaptured by researchers. Ultrasound imagery revealed the presence of well developed eggs, an indication that she would likely attempt to spawn in the spring of 2011. She had been found near river mile 750 (just upstream from Sioux City, Iowa) since September 2010… that is until April 11, 2011 when our research partners with the Nebraska Game and Parks Commission were suddenly unable to locate her in that area. Now she has moved? Where did she go? Upstream or downstream? Did she go up a tributary? Is she starting a spawning migration? Hopefully, as our high-intensity search and tracking efforts ramp up in the next two weeks we will be able to document another chapter of her life in the Missouri River.