Timely Events in Their Interrelation to Paddlefish and Sturgeon Harvest from 1945-2010

Due to the high amounts of harvest of natural fish populations, overexploitation can occur and subsequently lead to depleted fisheries. This is especially true for commercially exploited roe-bearing species that exhibit late age at maturation and intermittent spawning. Overexploitation can create an imbalance in natural ecosystem function and in turn jeopardize the livelihood of commercial fishers. Despite the problems created by overexploitation, trends of commercial harvest on large inland river roe-bearing populations have received minimal attention. As such, we evaluated trends in commercial fishing data from 1945-2010 for two roe-bearing species (paddlefish Polyodon spathula and shovelnose sturgeon Scaphirhynchus platorynchus) from two of the largest inland rivers in North America (Mississippi River and Missouri River) adjacent to Missouri. Commercial sturgeon and paddlefish catch has varied from ∼160 to 35,150 kg over the course of the 55-year duration. Abnormally high catches corresponded to initiation of worldwide caviar markets, onset of extensive regulations on the Missouri and Mississippi rivers, and the Caspian Sea fishery collapse; respectively. Further, our results suggest that the harvest of sturgeon and paddlefish have increased since 1945 and may be influenced by local, regional, and international events. Despite the increase in harvest and the possibility of overharvest, commercial fishing regulations have not been thoroughly evaluated for effectiveness. Further evaluation of current management and regulations of these paddlefish and sturgeon fisheries is suggested, especially considering these fisheries may be influenced by local, regional, and international events. Taking potentially influential events into consideration when evaluating and implementing regulations and authorizing commercial harvest permits are vital in sustaining a long term commercial fishery and protecting the livelihood of commercial fishers.