Upper Missouri Paddlefish Population

The Paddlefish is an ancient, mostly cartilaginous fish with a smooth skin. It is a close relative of sturgeons. Although it is sometimes called a spoonbill or spoonbill cat, it is not closely related to catfish. Most species of Paddlefish are now extinct, and fossil Paddlefish from 60 million years ago have been found in the Missouri River basin near Fort Peck Reservoir, Montana (Montana AFS Species Status Account).

Montana is home to one of the few remaining self-sustaining populations of Paddlefish, and harbors the largest individual fish as well. Specimens have been taken weighing up to 150 pounds. When Paddlefish mature, at about age 9 to 10 for males and age 16 to 17 for females, they migrate up river to spawn. During their spawning migrations, they are susceptible to harvest by anglers.

Adapted from Montana Field Guide

Paddlefish Polyodon spathula, are a k-selected species that are desirable in both recreational and commercial fisheries. Unfortunately, many paddlefish populations experienced declines in abundance as a result of habitat degradation and overfishing from the late 1800s to mid 1990s (Combs 1982; Graham 1997; Carlson and Bonislawky 1981; Bettoli et al. 2009). Given that paddlefish are long-lived and late maturing, they are particularly vulnerable to overfishing—similar to other species in the family Acipenseridae (Boreman 1997). Paddlefish conservation efforts throughout North America were initiated by the mid 1990s and identified population monitoring and stronger regulations as integral components for successful conservation (Scholten and Bettoli 2005; Bettoli et al. 2009). For sustainable commercial or recreational fisheries targeting k-selected species such as the Paddlefish, managers need accurate estimates regarding survival, abundance, and exploitation. Once these metrics are available, the status of paddlefish populations can be put in context of harvest leading to more informed management decisions (i.e., harvest regulations) that conserve the population and ensure sustainable fisheries.