Allegheny and Ohio River Study
Rivers are valued as multiple-use resources due to their social, cultural, and economic benefits, but there is a very limited amount of information available to guide managers in decision making. This lack of information is of particular concern when there is an interest in also managing rivers for ecosystem values and as habitats for aquatic life.
To address this issue, the Western Pennsylvania Conservancy is developing a river information system to guide river conservation and decision-making. In order for this tool to be effective it must incorporate a wide variety of in-depth data about key aspects of river health. Examples include knowledge about water quality, river flow velocities, river depths, river bed types and conditions, populations of aquatic life, overlapping human uses of our rivers, and more. As this information is developed, it will be shared among government managers and conservation interests.
Progress to Date
Preliminary steps included building a comprehensive GIS catalogue of all relevant information about the Allegheny River. Navigational information (lock and dam structures, buoys, and marinas), obstructions (underwater cables, pipelines, and bridges), and water quality information (river flow, gauge height, and Pennsylvania Department of Environmental Protection data) were compiled into a robust database. Numerous Army Corps of Engineers navigation charts were scanned and georectified to build a river polygon into which all new depth data could be entered. Some important data sets did not exist and WPC is working to fill data gaps such as river depth data and information about freshwater mussel populations.
In an effort to better characterize depths and habitats found in the Allegheny and Ohio rivers, WPC has undertaken a large bathymetry mapping initiative, the first of its kind in the Upper Ohio River watershed. The objective is to build a visual representation of current depth profiles found in the Allegheny River pools section and to incorporate the information into a GIS where depth can be associated with other factors of river health. A pilot project was undertaken using a consulting firm to assess certain areas of the Ohio River prior to WPC developing the capability to conduct the study.
WPC uses a 23-foot research vessel for river research. WPC scientists use it for research projects that involve scuba diving and the need to learn more about what is happening below the surface of our rivers through river bottom mapping. The primary focus of the 2007 field season was to complete all necessary bottom mapping for mussel studies taking place in Allegheny River Pools 5, 6, 7, and 8. Mapping efforts began in May of 2007 and these activities were completed in 2010. We have discovered some localities that could be considered suitable habitat for freshwater species based on depth characteristics, although other important ecosystem attributes still require investigation, e.g., flow rates. In addition to relatively shallow habitats, we have also found locations that have been significantly altered by human activities. Future mapping efforts will be completed as time and funding allows. WPC plans to disseminate mapping products to other parties and is exploring the option of hosting this information on a WPC server which could be navigated from the internet.
Freshwater Mussel Survey Project
From 2005 to 2010, WPC/PNHP staff used funding from a Pennsylvania State Wildlife Grant and the United States Fish and Wildlife Service to conduct surveys for freshwater mussels in pools 4, 5, 6, 7, 8, and 9 of the lower Allegheny River.
Mussel sampling was conducted by pairs of SCUBA divers, following protocols developed by the Ohio River Valley Ecosystem Team (ORVET) Mollusk Group. Transects 100-meters long were placed perpendicular to river flow and each transect was divided into 10-meter segments. Paired SCUBA divers searched for a minimum of 10 minutes in each 10-meter segment, unless conditions or habitat were unsuitable. Mussels were gathered and placed into mesh bags according to transect segment. In addition to mussel searches, underwater habitat was assessed in each 10-meter segment. All mussels were brought to the surface and identified, counted, measured, photographed, and released immediately following processing. Representative samples of dead shells were collected as reference specimens to be deposited in the Carnegie Museum of Natural History.
Eighty-six dives were conducted over the course of the past three years. During these searches, we found over 1500 freshwater mussels and documented a total of 23 native species, including two federally endangered mussels, the northern riffleshell (Epioblasma torulosa rangiana) and the clubshell (Pleurobema clava). We also found several mussel species of conservation concern in Pennsylvania, including the rayed bean (Villosa fabalis), rainbow mussel (Villosa iris), round pigtoe (P. sintoxia), Wabash pigtoe (Fusconia flava), and longsolid (F. subrotunda). Pennsylvania State Threatened threeridge mussels (Amblema plicata) and salamander mussels (Simpsonaias ambigua) were also found.
Our SCUBA surveys have expanded our knowledge of the spatial distributions and habitat preferences of freshwater mussels in the navigational pools of the Allegheny River. Ultimately, this information will lead to protection efforts for remaining viable freshwater mussel populations as well as restoration efforts for species lost from portions of their historic ranges.
Habitat Restoration and River Ecosystem Management
All of the information being collected for the GIS river information system is providing a better understanding of the characteristics and health of the region’s working rivers. As this system is developed, it will be provided to a variety of government agencies and selected conservation groups for use in river management and restoration projects.
The ultimate goal of the Conservancy’s Upper Ohio River basin work is to protect and improve river environments that provide habitats for aquatic life, and that also allow aquatic life to move up and down the region’s rivers in a fashion that provides natural connections for populations of fish, mussels, and other aquatic organisms.
Other Projects and Partners
- Goals and objectives discussed with U.S. Army Corps of Engineers, Pennsylvania Fish and Boat Commission, U.S. Fish and Wildlife Service, The Nature Conservancy and others.
- Scope of pilot project developed with U.S. Army Corps of Engineers to research the potential to restore high-quality riverine habitat in the Lower Allegheny River, Allegheny County.
- Provision of bathymetry data to U.S. Fish and Wildlife Service and U.S. Army Corps of Engineers for use in designing a habitat restoration project in the Ohio River, Beaver County.
- Bathymetry data for Allegheny River Pool 6 provided to U.S. Fish and Wildlife Service for use in refining endangered species management decision-making.
- Data shared with the Port of Pittsburgh Commission for use in better representation and management of the resources that comprise the region’s “working rivers.”
- Bathymetry mapping provided to Pennsylvania Fish and Boat Commission for use in the review of permit applications regarding river mining projects.