Long-Term Trends in Brook Trout Habitat in Appalachian Headwater Streams

For lotic salmonids, pool habitats are critical to persistence and resilience. In the central Appalachians, brook trout (Salvelinus fontinalis Mitchill 1814) is an imperiled species that relies on pool habitats for refuge during drought and for spawning. We sought to study trends in pool habitats by studying habitat distribution and trends in 25 headwater systems over 18 years. Our analysis documented a significant decreasing trend in critical pool habitat (p = 0.006) and a significant increase in distance between these pools (p = 0.001) since 2003. Natural recruitment of large wood from second-growth riparian areas appears to be slower than losses. However, large wood recruitment from Superstorm Sandy in 2012, at least temporarily stabilized pool numbers. While salmonid populations can be highly resilient, disturbances can create unstable habitat conditions. These conditions could become more probable with projected alteration of flow regime due to climate change. These results highlight the need to further understand the potential impacts acute disturbances like drought, floods, debris flows, and other formidable events could have on temporal habitat availability.