The U.S. Fish and Wildlife Service and the Arkansas Game and Fish Commission (AGFC) stocked 288 endangered speckled pocketbook mussels (Lampsilis streckeri) in the upper South Fork tributary of Little Red River, Arkansas, May 12 and 13.
Both the Service and the AGFC work together to stabilize known populations of the mussel in the Little Red River basin. Service Deputy Field Supervisor of the Arkansas Ecological Services Field Office, Chris Davidson, was at South Fork in May.
“Augmenting populations can help the species re-establish sufficient numbers and distribution to sustain viable populations while biologists work with landowners in the upper Little Red River watershed to minimize and alleviate threats,” said Davidson. “Combined, these efforts will help recover the species and hopefully in the future it can be delisted.”
The mussel is grown in Greers Ferry Lake, with the help of the Greers Ferry National Fish Hatchery, until they are large enough to be placed into suitable habitat which helps the species maintain stable populations.
Although important to river ecosystems, many American freshwater mussel species are threatened and endangered. The speckled pocketbook mussel was federally listed as endangered in 1989 primarily due to loss and the decrease in quality of its habitat.
The mussel population disappeared in the main stem of the Little Red River from inundation following the construction of the Greers Ferry Reservoir dam, and cold water released into its tailwaters.
Furthermore, human activity in the Little Red River basin area, such as unpaved roads and the removal of trees up to riverbanks, has contributed excessive sedimentation.
“Some of the big boulders that they used to occur under have been totally buried under gravel and cobble,” said Davidson. “So, it is not only the fine silt and sand that we often think about making the river muddy, but also the courser sediments that come from unpaved roads and eroding streambanks.”
Many mussel species reproduce by infecting a host species of fish's gills with their parasitic young known as glochidia. They do this by using a lure that resembles a prey species that the host would likely eat.
The primary hosts for the speckled pocketbook mussel are largemouth bass and green sunfish, and their lures are evolved to attract them. The lures can sometimes resemble a small fish.
When the host fish takes a bite, the female releases the glochidia which attach to the gills where they will remain for a few weeks until they grow large enough to fall off. However, they must settle in the limited remaining suitable habitat to survive.
Erosion also causes rivers to widen, changing water temperatures, which is another threat to the species. According to Davidson, the threats the mussels face can be long lasting.
“Sediment is one of those that you can see legacy effects for decades after the initial input,” said Davidson. “It takes time for that excess sediment to work its way out of the system and for the river to reach equilibrium again.”
Since many listed species occur on or near privately owned property, the involvement of landowners in the conservation and recovery of species is crucial. Safe Harbor Agreements are just way you can help.
Landowners in the upper and lower Little Red River watershed interested in learning more about these voluntary agreements can contact us at the Arkansas Ecological Services Field Office.