Corbicula fluminea and native freshwater mussel competition for food resources

North Carolina Wildlife Resource Commission biologists and state and federal partners have noted the rapid continual decline of native freshwater mussel populations throughout NC.

The factors driving these declines are diverse and may include:

   • changes in land-use patterns

   • related increases in erosion and sedimentation

   • varied pollutants

However, declines in native mussels have been noted in some areas that have been relatively unaltered by human activity.

The introduction of invasive species has been related to the decline of other aquatic fauna, and the introduction and presence of Corbicula fluminea, the Asian clam, may be contributing to declines in North Carolina’s native mussels. Once introduced into suitable habitat C. fluminea populations can expand rapidly both in density and geographically.

C. fluminea feeding is relatively nonselective, and their use of both suspension and pedal feeding may provide an ecologic advantage when food resources are scarce. High densities of non-native species could significantly impact the availability of food resources for the native unionids.

The goal of this project is to examine the role C.  fluminea may play in limiting dietary resources available to North Carolina’s native freshwater mussels.

Specific objectives include:

            1) Measuring the effect of varying densities of C. fluminea on the comparative growth of selected species of captive-reared native mussels

            2) Assessing the comparative relationship between selected native mussel and C. fluminea comparative gill surface morphology and food particle ingestion.