Restoring the Wabash River to its preindustrial state by using a toolbox of modern conservation applications would serve as an example for states and even some nations to fix their large waterways, says a Ball State University researcher.
In his paper, “Conservation potential of North American large rivers: the Wabash River compared with the Ohio and Illinois rivers,” Mark Pyron, the George and Frances Ball Endowed Chair in Environmental Sciences in the Department of Biology, examines conservation efforts for the Illinois and Ohio rivers and suggests potential steps for protecting and conserving the Wabash River that could be applied to other large river ecosystems.
Mark Pyron, George and Frances Ball Endowed Chair in Environmental Sciences
Pyron notes that a large river conservation toolbox requires establishing a timeline and expectations for the potential status the ecosystem could achieve.
“Like similarly neglected large river systems worldwide, the Wabash River has a surprising amount of ecological resilience and recovery,” Pyron said. “For instance, of the 151 native fish species found in the 1800s, only three species have experienced local extinctions, making the modern assemblage more intact than many comparable rivers in the Mississippi River basin.
“Successful conservation for the Wabash River is possible and begins with reductions of nutrient from farm fields and sewers, mechanisms to restore historical hydrologic patterns, additional sediment controls, and improved local hydraulics.”
Although there were multiple stressors over the last century, the largest change in Wabash River fish biodiversity was associated with rapid increases in the dumping of sewage by municipalities and invasive bigheaded carps, he said.
The Wabash runs 503 miles from the headwaters near the middle of Ohio’s western border northwest then southwest across northern Indiana. Although there are numerous reservoirs on its tributaries and one mainstem reservoir at river mile 300, the lower two-thirds is still the longest undammed flow east of the Mississippi River.
Pyron said many U.S. rivers suffered from similar problems as most of the tributaries of the Mississippi River basin. These include well-documented progression of human activities from shifts in land-use and agricultural practices, pollution from sources such as sewers and farm fields, hydrologic alterations from dam and reservoir construction, and the establishment of invasive species.
Pyron points out that several researchers have recommended ecological restoration to reduce floods by increasing channel roughness, increasing in-stream habitat complexity with large boulders or large woody debris, or increasing wetland construction.
- Incentives for modification of cover crops in agricultural sub-watersheds to reduce peak flow runoff and subsequent nutrient spikes.
- Partnerships and policies like the proposed National Fish Habitat Conservation Through Partnerships Act to engage the public and politicians to stop ongoing degradation and promote important habitat restoration.
- Restore floodplains by allowing natural seasonal flooding.
- Build a partnership with representation from resource users, agriculture interests, and management agencies with the goal to identify and promote potential conservation, land-use modifications, policy, and mitigation to protect or improve watersheds in all rivers.
The study was published in the online issue of Fisheries and Aquatic Sciences in June.