The Cache River watershed has a unique community of slackwater fishes which are associated with low gradient, low velocity backwater habitats that typically have silt and organic detritus substrata. Most of these slackwater fishes are classified as Species in Greatest Need of Conservation (SGNC) because of their rare and declining status in Illinois. Historic records of 13 slackwater fish SGNC were used to determine species presence at locations with records over 10 years old and identify new locations. The lack of recent records for slackwater fishes may have resulted from deficiency in sampling bottomland habitats, or partially due to habitat loss, heavy sedimentation and hydrologic alteration.Survey sites were selected by identifying historic locations with multiple target species (> 2 species) and by identifying stream reaches with similar habitat characteristics to sites with known locations of target fish species. Similar habitat characteristics were determined by using existing ArcGIS datalayers associated with stream structure (e.g., discharge, watershed landuse) and modeled to all streams within the Cache River watershed.Nine out of thirteen slackwater species were present at slackwater survey sites \including five species at modeled locations. Modeling stream characteristics to locate fish SGNCwas successful and this technique could be applied to future research to assist with filling ecological and distribution information gaps of rare species in need of conservation. This research also supports the need for targeted surveys as a valuable supplement to existing fish sampling programs that do not regularly sample habitats that are specific tosome fish SGNC.
|Name||INHS Technical Report 2015 (44)|