Missouri River Rise

The Missouri River and its Spring Rise: Science and Science Fiction?


MARCH 15, 2006

Mr. Chairman and members of the subcommittee, I am Mitch King, Regional Director for the U.S. Fish and Wildlife Service’s (Service) Mountain-Prairie Region. I appreciate the opportunity to testify today on fish, wildlife, and the Missouri River on behalf of the Department of the Interior.

The Missouri River has undergone many changes since the journey of Lewis and Clark. At that time, settlers complained that the rich organic water of the “Mighty Mo” was “too thick to drink and too thin to plow.” Over the next 200 years, generations of settlers and the United States Government expended considerable resources trying to manage the river and carve out a safe and prosperous place to live. Through the creation of a system of Federal reservoirs and navigation-related infrastructure, we have created dependable hydropower, flood control, irrigation systems, and navigational opportunities for the benefit of the public.

Large river systems and their associated fish and wildlife resources have evolved over thousands of years, so major changes to a system invariably result in consequences. Harnessing the Missouri River resulted in significant changes to the populations of many native fish and wildlife species that once thrived in a free-flowing river. The status of the pallid sturgeon, least tern, and piping plover are all somewhat indicative of the changes in environmental health and diversity of the Missouri River system; each of these species is currently listed under the Endangered Species Act (ESA) as threatened or endangered.

The pallid sturgeon is native to the Missouri and Mississippi Rivers and is adapted to the pre-development habitat conditions that existed in these once large, warm, turbid rivers. The river’s floodplains, backwaters, chutes, sloughs, islands, sandbars, and main channels formed the large-river ecosystem that provided the habitat for the various life stages of pallid sturgeon.

Today, much of this ecosystem has been altered by human developments. The construction of dams and the regulation of the river for flood control and navigation captured the spring peak runoff flows in reservoirs for release during the late summer and early fall, when conditions are drier and river flows naturally lower. This loss of spring runoff flows, along with the loss of spawning habitat due to channelization of the river, have been the key contributing factors to the decline of the pallid sturgeon.

Restoring the physical habitat, providing for flow fluctuation, and augmenting wild pallid sturgeon populations will provide the “three-legged stool” for recovery of the species, and we’ve made strides in recent years in the areas of aquatic habitat restoration and artificial propagation of pallid sturgeon. However, the continual challenge facing the Service and our partners, the U.S. Army Corps of Engineers (Corps), states, tribes and stakeholders along the river, is to create a balance among the river uses, including the habitat needs of native fish and wildlife. We do not feel that, in the case of the Missouri River, we are forced to choose between the well-being of people and the needs of a species. By complying with the applicable laws, using the best scientific information available and applying common sense, we can provide for the needs of both people and wildlife.

Our December 2003 amended final biological opinion used the most current scientific information as the basis for recommending changes to management of the dams and set the stage for even more important collaborative discussions related to changing management of the river. The recommendations in the biological opinion are similar to those previously provided by the National Research Council (a subcommittee of the National Academy of Sciences) in their recent report “The Missouri River Ecosystem - Exploring the Prospects for Recovery,” as well as the Missouri River Natural Resource Committee, an organization comprised of state fish and wildlife agency officials from Missouri River basin states. Indeed, the National Research Council stated in its report: “Degradation of the Missouri River ecosystem will continue unless some portion of the hydrologic and geomorphic processes that sustained the pre-regulation Missouri River are restored - including...flow pulses that emulate the natural hydrograph. [Without them] the ecosystem faces the prospect of irreversible extinction of species.”

Flow pulses emulating the natural hydrograph, commonly referred to as spring rises, are increases in flows in the early part of a water year. Spring rises are intended to accomplish specific goals such as shifting sedimentation to create new channels, pools, and islands, which provide habitat for the pallid sturgeon; providing and transporting nutrients; and eliminating problematic plant life on river banks. Monitoring the environmental and biological effects of the current spring rise, as directed by the 2003 amended final biological opinion, will determine how successful we are in accomplishing these goals.

Future operation of the Missouri River with a spring rise will mimic natural conditions and help stimulate native river fishes, like the pallid sturgeon, to spawn and eventually provide young. Pallid sturgeon are extremely endangered. Only seven very young wild pallid sturgeon have been captured in the last seven years, indicating that there is little natural replacement of older sturgeon. Without a spring rise, we believe spawning and recruitment of wild sturgeon will not occur, placing the population in further decline.

In developing its recommendations for spring flow pulses, the Service relied on literally thousands of articles in published scientific literature related to large river ecology and native fishes. A river hydrograph characterized by seasonal ebbs and flows of water increases nutrients in the river which trigger insect production and smaller fish to reproduce – eventually providing food for young pallid sturgeon. This increase in water flow, coupled with the appropriate day length and temperature, also gives the right set of environmental cues necessary for the pallid sturgeon to complete its reproductive process.

The 2003 amended final biological opinion calls for adaptive management based on increasing knowledge of pallid sturgeon biology. Consistent with this mandate, we are making significant progress in our understanding of sturgeon life history. This will allow us to further refine our management actions in order to give sturgeon the best recovery chance possible while balancing river uses.

The U.S. Geological Survey (USGS), working with the Corps and the Service, is in the third year of a scientific research effort dedicated to furthering our understanding of the ecological requirements for reproduction and survival of sturgeon. USGS has been successful at developing procedures for placing transmitters and sensors in sturgeon to effectively allow the fish to help us determine what and where spawning habitat is, and when spawning occurs. This information will be critical in the evaluation of the benefits of the spring rise and how it contributes to successful spawning and recruitment.

The USGS has also developed protocols for evaluating habitat used by fish, allowing us to gauge the effectiveness of habitat restoration efforts. For example USGS has documented that patches of gravel-cobble substrate, thought to be preferred by sturgeon for spawning, exist throughout the lower Missouri River from St. Louis to Gavins Point. These findings indicate that potential spawning substrate is available in the area of the River influenced by the spring rise.

The science that USGS is providing on physiological conditions has resulted in an understanding of reproductive stage-specific hormone levels, enabling differentiation of sexes in sturgeon, as well as the ability to predict whether a fish will spawn in the upcoming summer. Over time and under different environmental conditions, these measurements allow us to best evaluate the sturgeon’s response to changes in its environment. A partnership of agencies that includes the USGS, the Service and several states are teaming together to use all of these techniques for evaluating the effectiveness of the pulses of the spring rise.

We understand and appreciate the concerns of the users and stakeholders in the Missouri River Basin. The Service and the Corps have been working in a collaborative effort with tribal representatives, Basin states, and a wide range of stakeholders. The spring pulse provisions in the Corps’ 2006 annual operating plan (AOP), which incorporated input from this Plenary Group, complies with the requirements of the ESA, while being responsive to hydroclimatic conditions in the basin and the potential impacts on people.

The Service is sensitive to the concern about potential flooding that may occur during the releases. The cooperatively developed AOP includes criteria specifically designed to minimize the risk of downstream flooding and crop damage. The Corps and the Service have agreed that the established downstream flow limits would not be changed under the 2006 AOP, providing similar downstream flood control as has been provided in previous years. In addition, the Corps has agreed, at the request of the downstream farmers, to adjust releases based on precipitation forecasts and estimated actual rainfall. These measures, along with the reduced duration and magnitude of the pulses, will reduce the potential for downstream flooding of cropland. We are confident in the Corps’ assessment of the minimal risks associated with a change in operation, and we will continue to support the Corps in its efforts to work collaboratively with stakeholders in the lower basin as they collect additional data related to this concern.

We also note that because System storage is low due to the current extended drought, releases for navigation in 2006 will be 6,000 cubic feet per second lower than normal, resulting in lower peak flows due to the spring pulse releases. In addition, the duration of the pulse, if one occurs this year, will be only 2 days, far shorter than has been previously discussed.

The Service’s goal is to ensure the actions proposed to prevent the extinction of native species are reasonable, based on sound science, and are within the authority of the Corps to implement. The proposed changes have been designed with safeguards related to flow constraints downstream.

The Service is proud to be working with our partners, including the USGS, state Fish and Wildlife Departments, tribal Fish and Wildlife Departments, the Corps, and basin stakeholders to develop a robust set of monitoring and evaluation programs that will ultimately be used to implement a scientifically sound adaptive management program on the Missouri River. We anticipate approximately a two year effort to convene the parties; establish measurable goals and objectives; and to begin implementation. To that end, we will continue to work with the Plenary Group and future cooperative groups and strive to best meet the needs of the people and resources of the Basin.

Mr. Chairman, this concludes my statement and I am happy to answer any questions that you might have. 

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