Importance and Issues
Aquatic biota have long been recognized as an important resource in the Blue Ridge, with brook trout playing a major role in the initial establishment of Shenandoah National Park in the 1920s. The relatively pristine and high elevation streams found in Shenandoah currently support cold water aquatic communities that are increasingly rare in Virginia and the Southeast. Because salmonids are sensitive to environmental change and are widely distributed in Shenandoah, brook trout populations are used as a measure of Shenandoah's cold-water ecosystem function.
Some threats to aquatic resources in Shenandoah are well documented -- acid deposition has long been recognized a threat to the ecological function of lotic habitats. In addition, recreational activities in the park frequently involve angling (primarily for brook trout), and public interest in fish population health is high.
An independent review by scientists and park managers indicated that, out of 43 potential vital signs that were assessed for Shenandoah, brook trout and fish communities ranked as the 3rd and 5th most significant based on combined ecological, management, and policy interests.
The relative rarity of cold water fish resources, along with the identification of known and persistent threats and management implications, in addition to a high level of public interest suggests that monitoring of fish populations is important for tracking vital signs.
- Determine long-term trends in fish species abundance, biomass, and community composition within sample sites over time.
- Determine long-term trends in biological condition (i.e. length and weight) and reproduction of game fish within sample sites over time.
- Determine relationships between physical and biological parameters (i.e. benthic macroinvertebrates) and fish community and population dynamics (species abundance, community composition, biomass, condition, reproduction, etc.) within sample sites over time.
- Establish thresholds of fish community or population metrics that inform management actions or initiate additional research activities.