9781934874127-ch3

Paddlefish Management, Propagation, and Conservation in the 21st Century

Paddlefish Populations in the Alabama River Drainage

Dennis R. DeVries, Gregory M. Lein, and R. John H. Hoxmeier

doi: https://doi.org/10.47886/9781934874127.ch3

Abstract.—The paddlefish Polyodon spathula occurs in the Mississippi and Ohio River drainages, as well as in several Gulf of Mexico tributaries. Populations throughout the Mississippi and Ohio River drainages have been relatively well studied, often relative to their exploitation. In contrast, the genetically distinct Alabama River drainage population has been studied relatively little. Here, we use both historical work and our own research conducted since 1992 to summarize population characteristics of the Alabama River paddlefish population and compare them to other stocks. We also examine the influence of flow on catch rates in the upstream reaches of this drainage during 1998–2003 and suggest where future work is needed to conserve this unique stock. Spawning temperatures and age at maturity were similar between Alabama and Mississippi river populations, and flow and adult paddlefish catch rates were positively related, suggesting that year-class strength may be related to flow, as has been shown for other populations. However, Alabama River paddlefish can spawn more frequently, grow faster, and have a much shorter life span. Previous work suggested that paddlefish throughout the Alabama River drainage were genetically distinct from other stocks, and recent work suggests that differences may exist between fish from the upper Alabama River and lower Alabama River. We argue that additional work with Alabama River drainage populations should focus on three areas: (1) detailed genetic work to identify differences among areas within the Alabama River drainage, as well as with other drainages; (2) quantify temporal and spatial variability in population characteristics of paddlefish throughout the entire range of the Alabama River drainage; and (3) quantify year-class strength and correlate it with flow/discharge to eventually predict recruitment and year-class strength in this unique stock.