High Definition Stream Survey information will improve the accuracy of habitat modeling.
Are you comfortable that the data obtained from a few site-based stream samples is adequate for your habitat modeling? Stream ecosystems are complex and conditions can change very rapidly, so habitat problems and their root causes can often be missed if assessments depend on site-based surveys. HDSS is designed to avoid this problem by collecting longitudinal geo-referenced data continuously over an entire stream corridor. Thorough documentation of all habitat issues will improve modeling effectiveness by incorporating more data about your stream.
Generally, habitat can be viewed as the home for stream animals. A healthy stream that can support a wide range of fish and invertebrates usually has a mix of different habitat types that provide the animals with their preferred living conditions.
HDSS documents changes to instream habitat conditions. Figure 1 displays a comparison of poor and excellent instream habitats. These locations are less than 1 mile apart on the same stream, and highlights how the variance in habitat conditions will be documented with longitudinal surveys.
HDSS also documents specific habitat conditions that can be reviewed in a dashboard format for context about the surroundings, or individually. Figure 2 shows an HDSS dashboard image that delineates habitat type (riffle, runs, and pools), substrate, substrate embeddedness, water depth, and instream cover. Scores for individual parameters can be combined to determine overall habitat condition.
Figures 3, 4 and 5 show individual examples of habitat type, embeddedness, and substrate types, respectively.
This video describes the methodology we applied to a habitat assessment on the Coosa River Bypass in 2018.