Navigational Pools in the Ohio River
To gain an understanding of the natural resources of a large river with many human influences, WPC set out to survey the Ohio River’s freshwater mussels.
The upper river drains a 23,500 square-mile watershed in Pennsylvania, New York and West Virginia. Its basin encompasses diverse urban, agricultural and natural landscapes. Once a river of flowing riffle and runs dotted with islands, the Ohio River was converted to slow, deep pools when the navigational pools were created in the late 19th century. Since the industrial revolution, the river has received pollution from resource extraction (e.g., coal mining and timber), manufacturing (e.g., steel, glass and other materials) and storm water. Additionally, the river is also a route for the transport of goods. Barges buzz through the locks and dams, moving coal and other materials every day of the year.
Despite past and ongoing threats, the river has experienced improvements in water quality since the peak of industrial pollution. While many assume that there is little life in the deep, silty waters of the river, recent studies of fish indicate that the river is recovering.
Because mussel communities in the Ohio River are still under-surveyed, divers from the Pennsylvania Natural Heritage Program don SCUBA gear and descend to transect lines on the river bottom. Feeling for shells in the top layer of sediments and looking for the telltale shape of mussel siphons, divers pull up freshwater mussels from the sandy river bottom.
Mussel diversity, habitat preferences of species encountered and evidence of population recruitment are useful for managing the river’s resources. Information from surveys and distribution modeling about the freshwater mussel communities, particularly any discoveries of species not seen in the river in recent decades or those that prefer high-quality habitat, are also beneficial to the management of the river.
A model of species distributions in the Ohio River basin will be developed as a result of this project. The model will draw a connection between the landscape and watershed features that are typical of waterways with freshwater mussels. The results of species distribution modeling can be used for future targeted surveys and give insight into the factors related to mussel habitat.
Brook Floater and Eastern Lampmussel Distribution
To meet the need for informed management of freshwater mussels in the commonwealth, WPC biologists are updating information about the distribution of brook floater (Alasmidonta varicosa) and eastern lampmussel (Lampsilis radiata) and assessing the conservation status. The significant range decline and decrease in population sizes of the brook floater and eastern lampmussel suggest that the species are reaching a critical threshold for conservation.
In previous studies, PNHP biologists have failed to find brook floater and eastern lampmussel at many sites where they had occurred historically. Both species have documented declines in the habitats in the eastern United States but more information must be gathered to fully understand the extent of the habitats and threats to the mussels. In this project staff members are searching other locations that have not been visited in many years to determine what habitats remain for both species.
Over the course of this ongoing project, we are determining the gaps in distribution information and revisiting historic locations for brook floater and eastern lampmussel habitat. We will estimate population density and collect water quality and habitat information at survey locations. Models of distribution for both species will be created to better understand the relationship between landscape characteristics and each species’ habitat.
Information gathered from this project will ultimately aid in the development of species action plans and conservation or restoration projects. If necessary, the species’ conservation status will be assessed for potential state listing.
