Statement of Problem: One of the few remaining concentrations of pallid sturgeon occurs in the Upper Missouri River between Fort Peck Dam and the headwaters of Lake Sakakawea, North Dakota. Individuals in this population also inhabit the Lower Yellowstone River in Montana and North Dakota (Bramblett and White 2001). Similar to pallid sturgeon in other regions, long-term viability of the pallid sturgeon population in the Missouri River downstream from Fort Peck Dam is in jeopardy. It is hypothesized that regulated flows from Fort Peck Dam coupled with a suppressed water temperature regime during the spring and early summer spawning period have failed to provide adequate spawning cues for pallid sturgeon. In addition, cold water releases from Fort Peck Dam have limited the amount of riverine habitat suitable for spawning. As a consequence, natural reproduction and recruitment of pallid sturgeon have not occurred for several years as evidenced by a population comprised of large (e.g., > 1200 mm; > 8 kg) and presumably old individuals. The U.S. Army Corps of Engineers (USACE) proposes to modify operations of Fort Peck Dam following specifications outlined in the Missouri River Biological Opinion. Modified dam operations are proposed to increase discharge and enhance water temperatures during late May and June to provide spawning cues and enhance environmental conditions for pallid sturgeon and other native fishes. In contrast to normal cold water releases through Fort Peck Dam, water from Fort Peck Reservoir will be released over the spillway during flow modifications to enhance water temperature conditions. The Fort Peck Flow Modification Biological Data Collection Plan is a monitoring and research program designed to examine the influence of proposed flow modifications from Fort Peck Dam on physical habitat and biological response of pallid sturgeon and other native fishes. The project is implemented jointly by the USGS-BRD and Montana Department of Fish, Wildlife and Parks.
Objectives:
The goal of this study is to evaluate the influence of proposed flow and water temperature modifications from Fort Peck Dam on physical habitat and biological response of endangered pallid sturgeon and other native fishes. This long-term study (2002-2010) contains several elements of the USGS Science Strategy (Understanding Ecosystems and Predicting Ecosystem Change) whereby information is obtained to understand the biology of pallid sturgeon and other native fishes under existing environmental conditions and under enhanced environmental conditions resulting from management actions. Objectives investigated between 2002 and 2010 include:
1) Examine the influence of modified discharge releases from the Fort Peck Dam spillway on water temperature and turbidity,
2) Examine flow- and temperature-related movements and river use (e.g., Yellowstone, Missouri, Milk) of pallid sturgeon, blue suckers, paddlefish, and shovelnose sturgeon via telemetry,
3) Quantify larval fish distribution and abundance,
4) Quantify the distribution and abundance of young-of-year sturgeon,
5) Examine drift rate, drift behavior, and transport of larval sturgeon,
6) Examine food habits of potential piscivores
7) Determine the location of and capture adult pallid sturgeon for spawning and propagation.