Lee County, Virginia
Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated.
Pesticide Table for Freshwater Mollusks | Pesticide Table for the Slender Chub
About Freshwater Mollusks | About the Slender Chub
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Pesticide Table for Freswater Mollusks
Limitations on Pesticide Use
|1||Do not apply this pesticide within 20 yards of the water's edge within the shaded area for ground applications nor within 100 yards for aerial applications.|
|2||Do not apply this pesticide within 40 yards of the water's edge within the shaded area for ground applications nor within 200 yards for aerial applications.|
|20||Do not apply directly to water within the shaded area.|
|40||Do not apply this pesticide to cattle within 100 yards of the water's edge within the shaded area. Do not allow treated cattle to enter the water in such a way that fenthion could wash off their backs and sides, for 100 days after treatment.|
|41||Do not apply this pesticide within 1/4 mile of the water's edge within the shaded area for ground applications , nor within 1/2 mile for aerial applications.|
|43||Do not apply this pesticide within 100 yards of the water's edge within the shaded area for ground applications , nor within 1/4 mile for aerial applications.|
Pesticide Table for the Slender Chub
|All Other Uses||1||--|
*TAR = Threshold Application Rate (Pounds of Active Ingredient per acre per application )
|1||Do not apply this pesticide within 20 yards of the water's edge within the the shaded area for ground applications, nor within 100 yards for aerial applications.|
|20||Do not apply directly to water within the shaded area.|
|41||Do not apply this pesticide within 1/4 mile of the edge of water within the shaded area for ground applications , nor within 1/2 mile for aerial applications.|
|43||Do not apply this pesticide within 100 yards of the edge of water within the shaded area for ground applications , nor within 1/4 mile for aerial applications.|
|199||Do not apply this pesticide above the threshold application rate (TAR) indicated within 20 yards of the water's edge within the shaded area for ground applications nor within 100 yards for aerial applications.|
Freshwater mussel [Unionidae]
Freshwater mollusks found in this area include the Appalachian monkeyface pearly mussel, the Birdwing pearly mussel, the Cracking pearly mussel, the Cumberland monkeyface pearly mussel, the Dromedary pearly mussel, the Fine-rayed pigtoe pearly mussel, and the Shiny pigtoe. These mussels are in the family Unionidae, a family restricted to North America. A far larger percentage of this family are imperiled than any other taxonomic (species) group.
Freshwater mussels can live up to 50 years. In the parasitic larval stage of the mollusk lifecycle it is dependant on fish within its habitat for nutrients and mobility. However, only a few host fish are known. Mature mussels bury themselves in the riffles and shoals and feed by siphoning phytoplankton and other plant matter from the water. Reverse siphoning is used to expell undigestible particles from the shell. Silt in the water can kill mussels by clogging their feeding siphons.
Major factors affecting mussel populations are alterations in temperature, waterflow, and siltation caused by stream damming and channeling. Agricultural runoffs and industrial practices have also affected the mussel habitat by degrading water quality and causing siltation. Because mussels are filter feeders, the effects of pollution are intensified due to the large quantities of water drawn through their siphons in the feeding process. Another significant threat to this species is the widespread and rapid population growth of the introduced zebra mussel. The zebra mussel not only competes with native species, but also attatches to them, adding so much weight that the native species cannot open to feed. In the past, commerial harvests contributed to the decline of freshwater mussels but this industry has since been reduced.
Matthews, J.R. (ed.), The Official World Wildlife Fund Guide to Endangered Species, Beacham Publishing Inc, Washington, DC. Vol II, pp. 955-956.
Slender chub [Hybopsis cahni]
The slender chub is a small, elongated minnow that grows to a maximum length of about 7.7 centimeters (3 in). It is olive to brown above, silver on the sides, whitish below, and with a dark lateral stripe. It is also characterized by having a long snout, large eyes, a slightly underhanging mouth. Little is known about the slender chub's reproductive behavior but spawning is believed to occur in late April and extending into early June. Life expectancy is 3 to 4 years and it feeds primarily on insects and mollusks.
Slender chub habitat from spring to fall is large warm streams 30 to 125 meters wide, which have wide shoals of clean gravel. The winter habitat is unknown. This species is endemic to the upper Tennessee River basin and has been recorded from the Clinch, Powell, and Holston Rivers. However, the Holston River population has not been seen since 1941. This minnow has one of the smallest ranges of any eastern North American minnow, being found in only nine population centers on the Powell and Clinch Rivers in Tennesse and Virginia.
The Holston River population disappeared after completion of the Cherokee Reservoir. The river above the reservoir is now silted and polluted while the water below is too cold for chub survival. Clinch River populations have also suffered from reservoir development and from chemical spills and discharges. The Powell River headwaters are affected by the coal mining industry which contributes to siltation and pollution of the water. Gravel shoals have been dredged in the the Clinch and Powell rivers which has also resulted in loss of habitat. Recovery of the slender chub relies heavily on the concerted effort of industries and authorities to lessen the contamination of the watersheds.
Matthews, J.R. (ed.), The Official World Wildlife Fund Guide to Endangered Species, Beacham Publishing Inc, Washington, DC. Vol II, pp. 885-886.
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