Fishery Resources, Environment, and Conservation in the Mississippi and Yangtze (Changjiang) River Basins

<em>Abstract</em>.—This chapter provides a listing of fishes known to be present in the Mississippi River from the headwaters at Lake Itasca, Minnesota to the Gulf of Mexico terminus. A total of 188 species are presently known from the Mississippi River, including 3 diadromous species and 17 nonnative species that have established self-sustaining populations in one or more reaches of the Mississippi River. Species are classified into three relative abundance categories and noted as residents, peripherals, introduced (established nonnatives), or strays (introduced but not established). The diversity of fishes varies longitudinally with 78 species in the reach from the headwaters to St. Anthony Falls; 113 and 105 species in the upper (Upper St. Anthony Lock and Dam to Pool 13) and lower (Pools 14–26) impounded reaches, respectively; and 121 and 136 species in the upper (Missouri River confluence to Ohio River confluence) and lower (Ohio River to the Gulf of Mexico outlet) free-flowing reaches, respectively. Although the composition of the Mississippi River fish fauna has changed little despite more than 80 years of habitat alteration, the extirpation of five species in individual reaches of the river may be a forewarning of a system losing resiliency and indicate the need for habitat conservation and rehabilitation to conserve the biodiversity of North America’s largest river.