Habitat Conservation Program
North Carolina's population has increased at a high rate with continued rapid growth projected. Many people move to North Carolina to retire, and many follow jobs to the state. This growth in population and industry equates to a significant increase in both residential and industrial development and a corresponding decrease in habitat for fish and wildlife.
One of the more significant habitat alterations has been to wetlands. North Carolina has lost and continues to lose wetlands at an alarming rate. According to the 1994 US. Fish and Wildlife Service Report "Southeast Wetlands: Status and Trends, Mid- 1970s to Mid- 1980s", freshwater, forested wetlands declined by 3.1 million acres in the southeast region (Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina , South Carolina & Tennessee). An estimated 38.8% (1.2 million acres) of this loss occurred in North Carolina. Wetlands are especially important as they provide habitat for fish and wildlife; store floodwaters; recharge groundwater; filter nutrients, sediment, and other pollutants; and provide carbon to aquatic systems. Therefore, it is especially critical to protect the state's remaining wetlands.
The quality of rivers and streams depends upon conditions within the watersheds. Adequate habitat and good water quality are essential to maintaining sport fisheries and other aquatic life. Nutrients contained in runoff from residential developments, golf courses and agricultural operations (both row crops and livestock operations) and in effluents from industry and municipal waste treatment plants have caused the nutrient enrichment of several major river systems including the Cape Fear, Chowan, Roanoke, Neuse, New and Tar-Pamlico. Sedimentation, the number one pollutant, significantly reduces the productivity of most streams and rivers in the state.
Many streams across the state are degraded due to development projects or agricultural operations. In many of these streams fish communities and other aquatic fauna have declined significantly, which has reduced or eliminated angling opportunities. We have demonstrated that streams and fishing opportunities can be restored by working with streamside or riparian land owners through signed conservation agreements and by applying principles of stream dynamics and sedimentation control. It is important that we develop a priority list and proceed with restoration of degraded streams.
State and federal laws charge the Wildlife Resources Commission (WRC) with protecting, managing and conserving aquatic, wetland and upland habitats for the benefit of fish and wildlife populations. The Habitat Conservation Program implements this mandate based upon the Commission's Policies and Guidelines for Conservation of Wetlands and Aquatic Habitats.
The goal of the Habitat Conservation Program is to protect and enhance wildlife and fisheries resources by 1) assessing impacts and providing recommendations to avoid or minimize those impacts through permit and environmental document review, 2) providing technical guidance regarding habitat conservation to governmental and private agencies and to individuals, 3) restoring degraded streams by correcting problems in riparian corridors that have resulted in poor water quality, sedimentation, unstable stream banks, loss of aquatic habitat and diminished fish communities, and 4) encouraging adequate mitigation for losses of fish, wildlife, their habitats, and uses thereof resulting from land and water developments.
During the past biennium (1 July 1994 - 30 June 1996), habitat conservation biologists reviewed 3,995 proposed projects statewide and evaluated the potential environmental threats associated with each project. We recommended project design modifications to minimize adverse environmental impacts and also recommended mitigation to compensate for unavoidable impacts. Evaluations of the program's effectiveness in influencing permit conditions were completed in both 1994 and 1995. We were able to influence permit conditions 70 percent of the time in 1994. In 1995 our success rate increased to 80 percent.
In the Coastal region, we continued to review and provide input for mitigation and reclamation activities associated with Potash Corporation of Saskatchewan's large phosphate mining operation. We also provided input and attended meetings to discuss the deepening and widening of the Wilmington Harbor channels; mitigation for Global TransPark; and Camp Lejeune's Greater Sandy Run Mitigation Bank. The majority of our permit review during this biennium was associated with coastal development activities, the most common being shoreline stabilization, piers construction, marina development and small channel dredging. Cumulative impacts associated with these projects are contributing to the increase in shell-fish harvesting closures as well as decreasing the vegetation necessary for juvenile fish growth and development.
The Piedmont region has continued to experience rapid growth during the biennium, increasing the need for additional infrastructure such as water treatment facilities, wastewater treatment plant upgrades and water and sewer line expansions. While the upgrades and expansions of wastewater treatment plants normally result in cleaner effluent through better technology, the potential improvements to aquatic systems are not being realized because streams are forced to assimilate more effluent. Secondary and cumulative impacts associated with additional infrastructure are also contributing to degradation of lakes and streams. The expansion of these utilities continue to destroy, degrade and fragment important fish and wildlife habitat.
There has been some preliminary work on new reservoirs, including Little River Reservoir. Buckhorn, West Fork Eno River and Randleman reservoirs are still in the environmental review stages. These three projects will have significant adverse effects on wetlands, stream habitat, protected species, and wildlife associated with high-quality bottomland habitats. We are working with other state and federal agencies to insure that impacts for these major projects are minimized. Most of this effort is in recommendations on compensatory mitigation packages.
Wetlands and wetland loss continue to be a major concern. Small losses are particularly significant in the Piedmont where wetlands are fewer in number and assaults come from many directions. The cumulative effects of these wetland losses will contribute to continued declines in wetland dependent species and in water quality, and increases in flooding. We are working with the Natural Heritage Program and the NC Forest Service to influence Forestry Best Management Practices that will help protect water quality and habitat in forested wetlands.
In the Mountain region, frequent and severe flooding has resulted in damage to many streams from debris blockages and erosion. We reviewed numerous proposals for work in streams sponsored by the Natural Resources Conservation Service (NRCS) as part of their Emergency Watershed Protection Program (EWP). EWP provides assistance to landowners to relieve imminent hazards to life and property from floods and other natural disasters. We were not concerned with proposals to return streams to their original course and remove downed trees and other debris from streams to avoid future damage to bridges and culverts; however, we were very concerned about proposals to dredge gravel and rock from streambeds and pile this material on banks for stabilization. These activities have the potential to degrade aquatic habitat, especially in trout streams, besides being short-term solutions to large problems in a watershed. Multiple flood events verified the short-term nature of this work. As a result, the NRCS has joined staff of the Wildlife Resources Commission and other state and federal agencies to examine more environmentally sound methods of stream restoration. Interagency flood response teams are being developed to respond rapidly to landowner needs while taking into account natural tendencies of streams and protection of aquatic habitat.
During the biennium, biologists reviewed 366 highway improvement projects and in many cases recommended design modifications or alignment shifts to minimize impacts to wildlife and fishery habitats. Linear roadway projects often have multiple stream crossings an can affect many different habitat types. Habitat fragmentation is a major contributing factor in overall wildlife habitat degradation. This is especially true when roadways are built on new location. Not only does the roadway cover valuable wildlife habitat, the roadway now acts as a barrier to wildlife movements or results in mortality as animals continue to access preferred feeding or resting areas by crossing the travel lanes.
We work closely with the N.C. Department of Transportation (NCDOT) to develop mitigation strategies to offset this loss of wildlife and fisheries habitat. We identify areas that should be preserved and help restore habitat on previously disturbed areas. In the Mountain region, one large highway project will result in as much as 10,000 feet of high-quality streams-either trout streams or tributaries to trout streams-to be placed in culverts. As mitigation for this loss of high-quality fishery habitat, the NCDOT has agreed to set up a restoration fund to be administered by the Wildlife Resources Commission for restoration of approximately 25,000 linear feet of degraded streams. Ultimately, the restoration will involve bank stabilization, fencing livestock out of the stream, revegetating stream banks, installing fish habitat enhancing devices, and purchasing conservation easements to protect the areas that have been restored.
We also worked with the NCDOT on wetland mitigation projects. In the Coastal Plain, improvements are ongoing along almost every major US highway. These roadways are being upgraded to deal with the increased amount of tourist traffic bound for the North Carolina coast. Although this makes a trip to the beach shorter and safer, it is not without a price. The bypass roadways around coastal communities often impact some of our highest quality rivers and wetlands. For example, improvements to US 17 will affect approximately 1,100 acres of wetlands that not only provide high-quality wildlife and fish habitat, but also perform important water-quality functions. US 17 crosses the Pasquotank, Perquimans, Chowan, Roanoke, Pamlico, Neuse, Trent, White Oak, New, and Cape Fear rivers. With impacts of this magnitude it is easy to understand why NCDOT projects require a great deal of wetland mitigation. During this biennium we have provided input on wetland mitigation sites in Currituck, Martin, Craven, Onslow, New Hanover, Brunswick, Wayne, Dare, Wilson, and Wake counties. These sites will be preserved as wetlands in perpetuity and some will provide recreational opportunities for the public.
Biological benefits of stream restoration
Biological benefits of stream restoration are derived from reestablishing important ecological functions on degraded streams. These are functions that can be observed and measured on high quality streams. Restoration accomplishes this by establishing a stable channel morphology which will support the development of a diverse stream ecosystem.
The stream channel includes the "normal flow" channel (between solid lines), the bankfull channel (large dashed line), and the floodplain channel above the bankfull elevation (variable width - depending on flood elevation). The quality of the stream ecosystem depends on these nested channels being present, stable and biologically functioning.
Biological benefits from stream restoration can always be assumed when a channel is taken from a degraded condition (as seen on the left) to a restored condition (right). The degraded channel has no riparian vegetation, is incised, has limited substrate diversity, and limited aquatic habitat. The restored channel shows diverse substrate, riffles and pools, a well vegetated floodplain and habitat enhanced by woody material. This stable condition and diverse habitat holds great potential for an excellent stream ecosystem to develop.
Stream restoration using natural channel design attempts to construct the proper width and depth relative to the bankfull elevation. A stable cross-section allows for the proper sorting of bed material. The map above shows how material sorts to create a diverse channel bed. This diversity provides habitat for organisms that utilize various size substrates. Sorting also orients the bed particles so that the upstream edge is embedded and the downstream edge is elevated, creating a refuge for aquatic organisms living in swift water.
Sorting also provides gravel beds that are free of sediment, which is important to gravel spawning species like trout. Trout lay their eggs in clean gravel during the late fall and early winter. The large eggs mature in the gravel for 2 to 3 months and, even after hatching, the fry remain in the gravel until the yolk sac is absorbed. If a heavy sediment load covers the gravel during this time the young trout will suffocate. Restoring a stable channel morphology that creates and maintains quality spawning habitat.
Diverse habitat in terms of varying depth, substrate and instream cover is essential for diverse fish assemblages. Darters and other benthic species need clean beds of large cobble for feeding, cover and reproduction. Most other fish species utilize the water column. Feeding is done by watching for food items from low velocity cover and moving into high velocity areas to pick out food particles. Predatory species like trout need hiding cover from which they can ambush their prey and hide from larger predators.
A condition common to many degraded streams is the absence of woody vegetation. Often these degraded channels will have herbaceous vegetation, but a shallow rooting depth limits the ability of this kind of vegetation to stabilize stream banks (see picture left). The picture to the right shows one tree on the bank of the Pigeon River in Haywood County. The root mass from this one tree is protecting the stream bank for over 100 feet. If this tree and its root mass were removed the channel would erode this bank laterally for some distance. Stream restoration projects provide for long-term stability of restoration sites by extensively planting stream riparian zones with native woody vegetation. This is particularly important around woody structures such as rootwads and vanes made of logs because this woody material will eventually decompose. Trees and livestakes planted around these structures will produce an extensive root structure before this woody material is completely broken down.
Aquatic invertebrates play an important role in stream ecosystems. They serve as the intermediate step between primary productivity and higher consumers. Because of their size and mobility they can survive in small areas of habitat and are often the first to colonize new or temporary aquatic habitat. Aquatic invertebrates have variable tolerances for differing water quality. This makes them excellent indicators of stream condition.
Flood plains are often called buffers because they buffer streams from upland water quality impacts. One way this occurs is shown in this photo. The stems of riparian vegetation slows the water flowing across the flood plain, allowing suspended sediment to be deposited. This quickly becomes vegetated, stabilizing the soil and reducing its impact on aquatic organisms.
Riparian vegetation also acts as a thermal buffer to the stream. Temperatures are as much as 5 degrees cooler during the day and slightly warmer at night inside the riparian zone. This thermal stability enhances the aquatic and terrestrial habitat quality.
Well vegetated flood plains are important to terrestrial organisms such as deer, bear, migratory birds and many others. The landscape in the 21st century is well developed. The ability of large mammals to move from one island of habitat to another safely is dependent on vegetated connections provided by riparian zones.
For restored streams to reach their full biological potential, they must be protected. This may be done through a conservation easement, a fee-simple purchase or some other method. It is only through protection that high quality habitat can be realized.
For some time natural resource managers have attempted to preserve and protect the biological functions of rivers and streams through regulation of activities within these habitats. However, the quality and quantity of this habitat continues to decrease. Stream restoration through natural channel design provides methods and opportunities for reversing this trend and for providing the public with the high water quality and natural areas they desire.
