Otolith microchemistry for determining natal origins of prey fishes in the Upper Mississippi River System

This dataset includes otolith and water chemistry used for determining natal origins of individuals from six species. The dataset contains Sr:Ca and Ba:Ca of water samples for the Mississippi River and tributaries as well as otolith Sr, Ba, Mg values from fishes collected in navigation pools 4, 8, 13, and 26 of the Upper Mississippi River, as well as the Open River Reach of the Middle Mississippi River and the La Grange Pool of the Illinois River. Fishes included Bullhead Minnow, Emerald Shiner, Gizzard Shad, Bluegill, Orangespotted Sunfish, and Yellow Perch. Laser ablation inductively coupled mass spectrometry to quantify natal origins of these prey fish. Upwards of 50-75% of individuals at a given river reach were identified as immigrant or tributary origin individuals that at some point in their life moved to the mainstem river where they were captured. Importantly, sources of recruits occurred both upstream and downstream from capture locations of these fishes indicating that movement within the river is not unidirectional. Combined, our findings underscore the need to manage or conserve the Upper Mississippi River System collaboratively among state jurisdictions.