Cooperative Fish and Wildlife Research Units Program: South Dakota
Education, Research and Technical Assistance for Managing Our Natural Resources

The larval phase of freshwater fishes is often characterized by high mortality. As with many fishes, the recruitment bottleneck for Pallid Sturgeon is believed to occur during their early life history. Recent work in the upper Missouri River has shown that the amount of riverine, drift habitat may be insufficient for larval development to transition to the fry stage. Moreover, cooler summer water temperatures in downstream reaches can prolong larval ontogeny, delaying the their ontogenetic development. Given current conditions in the river, Pallid Sturgeon larvae develop at slower rates and require longer migration distances compared to historic conditions. Working in collaboration with the U.S. Fish & Wildlife Service and the U.S. Department of Energy, the objective of this study is to quantify the effects of water temperature and water velocity on larval ontogeny (activity, growth, energy depletion) and mortality. Results from this study highlight the importance of an autecological approach aimed at understanding transitional life history attributes that affect recruitment success in pallid sturgeon.