Rivers of Life: the Importance of Protecting Tributaries

The Darby watershed comprises a
complex and interdependent series
of tributaries. Like most watersheds,
these tributaries are vital to the
overall health of the arterial stems.
Any significant alteration of the tributaries
may prove to have a "domino" effect within
the affected stream reach or segment,
and perhaps the entire main stem of the
watercourse.
Map © TNC

Clean water is essential to life. Creeks, streams, rivers and lakes are the circulatory system of our nation. These complex ecosystems provide countless services, from clean drinking water and recreational opportunities to transportation and food. The quality of our lives and the survival of freshwater species is directly tied to the health of our water.

Significant progress has been made over the last 20 years to protect and restore the physical, chemical and biological integrity of our waters. However, issues still remain that need attention and require creative solutions. An effective strategy for restoring and maintaining water quality is through a watershed approach. A watershed is the area that ultimately drains to a particular body of water. A watershed can include rivers, lakes, wetlands, streams, tributaries, and the surrounding landscape.

Ohio Example

Consider, for example, Darby Creek watershed in central Ohio. Big and Little Darby Creeks, the two main stems of the Darby watershed, are nourished by a complex network of smaller tributaries. Many of these originate from moraines, (an accumulation of earth and stones carried and finally deposited by a glacier) and flow through wet woodland systems. They provide cool, clean water and excellent spawning habitat for several threatened fish species. Many of these first and second order tributaries actually harbor very sensitive cold water habitat fish species like the mottled sculpin and the redside dace. These threatened species are especially predominant in many of the headwater capillaries that feed the Darbys.

Importance of Riparian Corridor

Stream channels shaded by vegetative corridors provide an abundance of invertebrates for juvenile and young fish species. These canopied corridors are excellent habitat for terrestrial insects, which in turn provide substance for several species of neotropical songbirds passing through and inhabiting the Darby watershed. Together, it is a complex system, an intricate web of interactive and dynamic relationships.

Reasons for Clean Water & Challeges for It

For all species to survive -- indeed for our own species to survive -- the limited amount of freshwater on Earth must be protected. And as The Nature Conservancy works to protect watersheds like Darby Creek and the Scioto River and the biological diversity that it represents, we must take a comprehensive approach which considers the surrounding landscape and the tributaries that feed into the main stems of our river systems. These smaller rivers of life are the lifeblood of the receiving main stems and are rich in biodiversity, making them a critical component in the overall protection of aquatic systems. Unfortunately, a significant portion of these tributaries in Ohio are subject to intensive land use changes.

Following agricultural runoff, sedimentation and habitat degradation are the second and third leading causes of aquatic life impairment in Ohio rivers and streams. These threats are having a major impact and are principally the result of landscape alterations from agricultural land use, urbanization and suburban development, and the subsequent impervious surface runoff associated with this growth phenomenon.

We don't often think how actions occurring upstream can impact aquatic life hundreds of miles downstream. Mussels, crayfish, amphibians, fish and freshwater plants are among the most imperiled species in the United States. In Ohio, many indigenous aquatic species, primarily fish and freshwater mussels, are imperiled. Thirty percent of Ohio's fish species are classified as rare, endangered, threatened, or special status (at the state level). Based on Ohio Environmental Protection Agency data collected since 1978, the proportion of imperiled fish species may now be as high as forty percent.

Cooperative Efforts will Benefit All

It was these grave statistics worldwide that prompted The Nature Conservancy to launch the Freshwater Initiative, a conservation effort that targets dozens of rivers and threatened freshwater systems rich in biodiversity throughout the United States and Latin America. The Conservancy will employ a variety of techniques to address two of the leading threats to freshwater biodiversity -- alterations in natural stream and river flow patterns due to dams, diversions, and ground water pumping; and sedimentation and polluted runoff from farms and urbanizing areas.

Across the country and in Ohio, The Nature Conservancy is stepping up conservation efforts to protect these critically important watercourses by putting more scientists in the water and on the land, acquiring key parcels of land along waterways, restoring riverside corridors, implementing innovative conservation strategies in local communities, working with local decision makers, and working with farmers to reduce sediment runoff. The protection and conservation strategies of our nation's watersheds are as diverse as the landscapes, communities, and political jurisdictions that they drain. Therefore, it is imperative to involve all the stakeholders when developing and implementing watershed protection goals.

Ultimately, the preservation of our nation's rivers of life will depend upon the decisions of many. We have an obligation to ourselves and to our descendants to safeguard our nation's watersheds, to ensure the survival of our aquatic biodiversity and to protect our own well-being and quality of life.