American Eel Habitat Use and Timing of Freshwater Entrance in the Mississippi River

The U.S. Fish and Wildlife Service (USFWS) announced October 15^th, 2015 that the American eel population is stable and endangered status was not warranted. Such a decision was based on information collected predominately from the east coast of North America with minimal information available from peripheral locations. As such, our study aimed to garner further information about American eels and the interrelations to the potentially limited habitats occupied in the Mississippi River. We used data provided by the Long Term Resource Monitoring (1993 to 2015) to carry out Non Metric Multidimensional Scaling (NMDS) to identify habitat associations with American eel. Furthermore, a subsample of American eels was collected from 2011-2013 (via daily electrofishing) to identify timing of freshwater entrance into the Mississippi River via otolith microchemistry. From 1993 to 2015 a total of 154 American eels were collected which were most commonly located in habitats characterized by rocky substrate and low velocity. From 2011-2013 a total of 40 American eels were collected for otolith microchemistry. Microchemistry results indicated American eels enter freshwater at approximately age two.