Pallid Sturgeon Bioenergetics Study
Habitats within the Missouri River have been greatly altered in response to dam construction and operations. Pallid sturgeon carrying capacity of these areas has also been changed although the extent is poorly understood. One method to explore interactions between fishes and their prey or assess habitat quality and carrying capacity is with bioenergetics models. Bioenergetics models can be used to assess food consumption of river fishes pre- and post-impoundment, over-winter mortality, the affects of bioaccumulation of toxic chemicals in fish, and energy availability (food). Once a bioenergetics model is developed, habitat quality of remnant riverine segments of the Missouri River for pallid sturgeon growth can be assessed in relation to water flows and temperatures resulting from various management regimes for dam operation. We acknowledge the assistance and cooperation of staff at the Bozeman Fish technology Center, Garrison Dam National Fish Hatchery, and Gavins Point Dam National Fish Hatchery to provide fish and tank space to conduct this project.
Experiments measuring juvenile pallid sturgeon metabolic (respiration) rates were initiated in 2003 and continued in 2005 at multiple temperatures and life stages (fish sizes). In 2003, measurements were made on 139 individual pallid sturgeon weighing 3 – 554 g across a temperature range of 4 – 21.5 ºC. In 2004, 17 experiments measuring pallid sturgeon metabolic rates were completed on 93 fish, 41 of which were in the larval life stage (< 1 g). In 2005, an additional seven respiration experiments were conducted on a total of 60 fish with further emphasis on early larval life stages. Data collection for metabolic rate is complete and analyses will be conducted during winter and spring of 2006.
In 2005, a MS level graduate student, Elizabeth Wright, at South Dakota State University (SDSU), started a detailed study of pallid sturgeon consumption and growth rates. Elizabeth is advised by Drs. Rob Klumb (FWS) and Steve Chipps (USGS, SD Cooperative Fish and Wildlife Research Unit). Feeding trials in the laboratory at SDSU measured the influence of fish body size, water temperature, and ration size on maximum feeding rates which constitutes a key physiological component of the bioenergetics model. Initial trials measuring pallid sturgeon consumption rates in relation to body size and water temperature were completed in 2004 by R. Klumb at the Bozeman Fish Technology Center and will be incorporated in Elizabeth’s study. Additionally, her growth experiments also provide data to assess and validate the bioenergetics model’s performance. Consumption and growth experiments should be completed this winter with data analysis and her thesis completed by summer of 2006. Elizabeth’s project is primarily funded by a State Wildlife Grant from South Dakota awarded to Drs. Chipps and Klumb which started on July 1, 2005.
Bioenergetics modeling simulations require measurements of water temperature. Submersible temperature loggers were placed in the riverine segments of Missouri River below Fort Randall and Gavins Point dams during 2003 and 2004 as part of a study on Asian carps and loggers were again deployed in 2005. This temperature data will also be used for future bioenergetics modeling analyses.
