Distribution and Life History of Clinch Dace (Chrosomus sp. cf. saylori) in the Upper Clinch River Watershed, Virginia

Abstract

In 1999 Clinch dace, Chrosomus sp. cf. saylori, was discovered in the Tennessee drainage of Virginia. Subsequent sampling of southwest Virginia and portions of Tennessee indicated that Clinch dace populations are small, fragmented, and of question viability. Further, riparian landuse and mining posed significant threats to critical habitat. As such, Clinch dace were listed as a Federal Species of Concern and on Virginia’s Wildlife Action Plan as Tier II- Very High Conservation Need. A management plan and species description for Clinch dace is of utmost importance, but data on distribution and life history is needed before these objectives can be realized." "The objective of this study was threefold: 1) more narrowly describe the distribution of Clinch dace in the upper Clinch River watershed, particularly in Russell and Tazewell counties, Virginia, 2) describe internal and external morphology to determine diet and life history characteristics, and 3) make in-situ breeding observations to determine timing and mode of reproduction. To complete these objectives, we sampled 60 streams and measured 12 habitat" "variables in 2011 and 2012. During sampling, we preserved 82 specimens which were used tomeasure internal and external morphological characteristics. We also used streambank observations and underwater videos to document spawning behavior. We conclude that Clinch dace are restricted to eight small tributaries to the Clinch River. Multivariate analysis of habitat correlates indicated that Clinch dace most commonly inhabit small, high elevation streams with gravel substrate and forested watersheds. Morphologic, meristic, and size-at-age characteristics were similar between Clinch dace and other Chrosomus; however, significant differences in digestive anatomy suggest Clinch dace occupy a different trophic niche than congeners. Like many Chrosomus, Clinch dace had an observed nest association with central stonerollers (Campostoma anomalum); however, gonad weight and mature egg counts were significantly lower for Clinch dace compared to congeners. Small population sizes coupled with several habitat threats suggest that Clinch dace viability is low in the present condition. As such, a proactive management protocol must be implemented in an attempt to conserve and recover remaining populations. We suggest that management be approached from three outlets including continued research, implementing conservation initiatives, and listing at the state and federal level. Future studies should focus on assessing perceived threats, in particular watershed development and barriers to connectivity, while maintaining a routine sampling protocol to determine spatial and temporal trends in populations. Conservation of Clinch dace habitat through preservation of riparian land and removing barriers to migration will increase juvenile viability and recruitment. Further, additional listing at the state and federal level could offer more legal protection for Clinch dace and allow for mandated riparian conservation.