Tallgrass prairies of the Grand River Grasslands (home to the Conservancy’s Dunn Ranch and Pawnee Prairies), are the most endangered, least protected habitat type on Earth. The most threatened aspect of these grasslands is the prairie headwater stream system and its associated wetlands and wet prairies. The sponge-like, porous soils of healthy tallgrass prairies absorb most rainfall, filtering it to the groundwater supply, where it is gradually discharged to headwater streams throughout the year. Early settlers noted that Missouri’s prairie streams often had permanent flow even in their upper reaches, and were characterized by their clear water and abundance of fish.
The devastating loss of prairie during the past 175 years has resulted in the severe degradation of almost all of Missouri’s prairie headwater streams. Surface runoff and lack of infiltration in the watershed cause frequent floods after heavy rains, creating eroded, muddy ditches. In the summer, without permanent recharge sources, stream beds dry up completely. One victim of these changes is the Topeka Shiner, a silvery fish less than three inches long with a prominent black stripe. Topeka Shiners are restricted to prairie headwater stream systems, where healthy watersheds provide permanent water, even in dry periods. These fish formerly ranged from Minnesota to eastern Kansas, but are now found in a small fraction of their former abundance and range. In Missouri, Topeka Shiners once occurred in several streams; today they are known only from two populations in the state. Topeka Shiners are federally listed as endangered.
Recently, the Missouri Department of Conservation (MDC) developed techniques to raise the fish for reintroduction into healthy habitats. Since 2000, the Conservancy has been aggressively restoring prairie vegetation in the watershed and removing invasive species that can increase runoff. Concurrently, MDC has been conducting habitat suitability surveys, testing stream channel improvements, preparing potential spawning beds, and removing problem fish from old farm ponds, which can serve as valuable refuges and source populations for Topeka Shiners.
Pending public review, the Conservancy, MDC, and the U.S. Fish and Wildlife Service will determine if sites at Dunn Ranch and Pawnee Prairies are suitable for experimental reintroduction of Topeka Shiners. Jerry Wiechman, an MDC fisheries management biologist, says reintroduction “is an important step in maintaining species diversity and keeping Missouri streams healthy.” Wiechman thinks that landowners in the watershed will benefit from voluntary incentives for restoration and conservation practices, creating a win/win for producers and stream conservation. The return of healthy Topeka Shiner populations will restore an aspect of Missouri’s natural heritage and serve as an ongoing indicator of good conservation and land use practices.June 27, 2012
Doug Ladd is director of conservation science for The Nature Conservancy in Missouri. He has been involved for more than 30 years with conservation planning, natural-area assessment, management, restoration and research, with particular emphasis on vegetation, ecological restoration and fire ecology. He is author of two plant field guides — North Woods Wildflowers and Tallgrass Prairie Wildflowers — and numerous articles and reports.