Heather Ainsley
ECB Publishing, Inc.
In response to several lawsuits brought on by the Center for Biological Diversity, the U.S. Fish and Wildlife Service proposed a designation of critical habitat to the Suwannee moccasinshell, which was previously feared to be extinct. The Center filed a scientific petition in 2010 to list the two-inch mollusk under the Endangered Species Act and followed up with several lawsuits to force decisions leading to the moccasinshell's protection. The Act prohibits federal agencies from authorizing activities that will destroy or harm a listed species' critical habitat, and species with federally protected critical habitats are more than twice as likely to recover than those without it.
This August, a ruling went out designating about 190 miles of stream channels in Alachua, Bradford, Columbia, Dixie, Gilchrist, Hamilton, Lafayette, Madison, Suwannee, and Union Counties in Florida, and Brooks and Lowndes Counties in Georgia as critical habitat for the Suwannee moccasinshell. This rule is final and was published on the first of September on the Federal Register.
The Suwannee moccasinshell is a small mussel that was recently rediscovered in the Suwannee, Upper Santa Fe and Withlacoochee rivers. This mussel can easily be distinguished from all other mussels in the Suwannee River Basin by its oval shell and sculpture on its posterior slope. The males are often longer and less wide than the females, and while young mollusks may have yellowish-green shells with faint rays, mature adults are usually olive brown to brownish black in color.
These animals typically live in larger streams where it can be found in substrates of muddy sand sandy gravel in areas with slow to moderate current. Individuals are also associated with large or woody material, such as fallen trees and embedded logs. Like other mussels, the Suwannee moccasinshell is a filter feeder, and obtains sustenance from its surroundings by taking in water through a siphon and filtering it over four specialized gills, which are used for both respiration and food collection. They feed on microscopic food particles, including algae, diatoms, bacteria and disintegrated organic debris.
The most significant cause of the Suwannee moccasinshell's population decline is the degradation of its habitat due to polluted runoff from agricultural lands, discharges from industrial and municipal wastewater sources and from mining operations. Additionally, decreased water-flow due to groundwater extraction and drought have impacted this species significantly. Another threat to this animal is competition and disturbance from the introduced Asian clam, which was introduced as a food source but has since become largely invasive, as it grows swiftly and reproduces in large numbers, forming colonies that can clog waterways and pipes.
While the ruling to designate critical habitat to the Suwannee moccasinshell is a huge step towards its recovery, the species has a long road to population recovery. Landowners who wish to help this species recover should consider best management practices when applying pesticides, fertilizers and irrigation water. Cities and towns in the basin can work to retain buffers and greenspaces along streams and rivers.
The Suwannee mocassinshell is considered “exceedingly rare” by NatureServe, according to their website: https://explorer. natureserve.org. Surveys conducted in 2013-2015 found less than 80 living individuals, and the species' fragility is reported to be highly vulnerable. At that time, only the population in the Suwannee River main-stem appeared to be viable, and was reported to be considered stable by the U.S. Fish and Wildlife Service in 2016. With the protection of its critical habitat, made official with the final rule in August, this species finally stands a chance at recovery.
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