These metals were thought to have potentially deleterious effects on aquatic life in Smith River and on the sport fishery downstream in Philpott Reservoir. However, the bioassessments revealed certain habitat-poor areas due to livestock watering and other deleterious farming practices. Increased silt loading and fecal coliform were observed downstream of these areas resulting in poor spawning habitat for the stocked kokhanee rainbow trout in the reservoir. Thus, elevated metal concentrations in this watershed appeared to have little or no ecological impact. On the contrary, biological approaches demonstrated that higher management priority should be given to mitigating and preventing habitat destruction in the riparian zone and instream.
Lower scores signify impairment.
In-Situ Bioassays, Ambient Water Testing, and Toxicity Identification Analyses Biological techniques can not only help prioritize watershed areas in need of remediation, as indicated in the above example. Benthic macroinvertebrate and fish biological assessments of this watershed, using a probabilistic and targeted sampling design, indicated ecological impairment in the town of Pulaski and downstream of an abandoned chemical manufacturing facility. Both habitat assessment data and results of in-situ bioassays suggested that the Pulaski site was impaired by poor riparian habitat and channel alteration whereas the abandoned factory site was impaired by toxic storm water runoff. Percent survival of indigenous species in in-situ bioassays in Peak Creek during dry and wet weather near Pulaski and at an abandoned factory. Ceriodaphnia survival in differently treated fractions of storm water collected downstream of the factory site.