The Topeka Shiner: Shining a Spotlight on an Iowa Success Story

by Aleshia Kenney

What started out as just an idea, with a few skeptical landowners in the early 2000s, has turned into a true success story in Iowa. Blending the U.S. Fish and Wildlife Service’s (Service) Partners for Fish and Wildlife Program with endangered species habitat restorations has served as a major stepping stone towards recovery for the endangered Topeka shiner (Notropis topeka).

The Topeka shiner, a minnow that grows to be no larger than three inches in length, was once abundant in many streams and rivers throughout the state.  The species began to decline, however, as conversion of Iowa's native prairies to agriculture degraded prairie streams and important instream habitats.  Modern practices to improve drainage and maximize planted acreage continue to threaten the species, which was listed as federally endangered in 1998.  Conserving this fish in Iowa will require maintaining and expanding existing populations.

Because little was known about the Topeka shiner's life history and habitat use at the time of listing, initial recovery actions focused on research.  Studies conducted by Kansas State University, Iowa State University, South Dakota State University, and others delivered critical information on spawning behavior and diet. However, discovering that this small prairie fish often uses off-channel habitats has made all the difference.

Pre-settlement Iowa was covered in prairie, with streams naturally meandered over the landscape, creating cut-offs and meander scars on the outside loops of the main stream channel.  Over time, these loops became U-shaped ponds, known as oxbows, which reconnected to the stream only during high water periods.  Oxbows provided the perfect pool-like habitat the Topeka shiner requires for spawning and rearing.  To improve drainage on farmlands, these naturally meandering prairie streams have been straightened and channelized, halting the creation of oxbows and other natural pools.  Over the years, old oxbows have filled with sediment and are no longer deep enough to support fish year-round. The Topeka shiner, and other fish that require off-channel habitats for all or part of their life cycle, move into these oxbows during spring flood events, but cannot survive through the summer months when the oxbows begin to dry.    

In Iowa, landscapes surrounding the watersheds that still support the Topeka shiner are littered with old oxbow scars. These scars represent potentially restorable habitat, provided landowners are willing to participate in restoration activities. In 2000, the Service's Rock Island Ecological Services Field Office, in partnership with the Iowa Natural Heritage Foundation, funded research exploring oxbow restoration on privately owned land.  At first, the initiative was met with skepticism, but there were some conservation-minded landowners willing to participate in oxbow restoration.  Restoration required removing sediment that had built up in the oxbow to increase its depth and capacity to hold water throughout the year.

To date, the Service's Partners for Fish and Wildlife Program, with support from the Iowa Natural Heritage Foundation, the Natural Resources Conservation Service, the Iowa Department of Natural Resources, and The Nature Conservancy, has restored 53 oxbows in the North Raccoon River watershed and another in the Boone River watershed.  Many of the restored oxbows now support Topeka shiners, and reproduction has been documented. In 2009, 354 Topeka shiners were found in one restored oxbow alone. Additional restoration projects for both the Raccoon River and Boone River watersheds are planned, and the success of these restoration projects has created an outpouring of interest from other private landowners in habitat restoration for the Topeka shiner. 

Oxbow restoration is a major step towards recovery of the Topeka shiner in Iowa, since these off-channel ponds provide habitat in a landscape that has changed dramatically over the years. Ongoing threats to the species in Iowa includes grassland conversion for row crop agriculture and changes to stream hydrology caused by dams. New challenges may also lie ahead in the conservation of the species as a result of climate change. Oxbow restorations, in varying degrees, help reduce these threats, by providing sustainable habitat, which mimics that which has been lost within the stream due to factors like channelization, allowing the species to persist into the future.

In addition to basic water quality benefits, these wetlands produce abundant quantities of food for amphibians and reptiles, as well as habitat for waterfowl and other migratory birds. Even smaller sites of an acre or less can support hundreds of frogs, toads, and salamanders. Typical of most conservation actions for endangered species, the benefits of oxbow restorations extend far beyond Topeka shiner recovery.

Aleshia Kenney, a fish and wildlife biologist of the Partners for Fish and Wildlife Program in the Service's Rock Island Ecological Services Field Office, can be reached at aleshia_kenney@fws.gov or 309-757-5800, ext. 218.