Initial development work completed for algae-based stream scoring tool

SCCWRP and its partners have completed initial development work on an assessment tool that will score the ecological health of California wadeable streams by analyzing the condition of in-stream algal communities.

The Algal Stream Condition Index (ASCI) is modeled after the California Stream Condition Index (CSCI), co-developed by SCCWRP and unveiled in 2015. While the CSCI uses bottom-dwelling macroinvertebrate communities as biological indicators of stream condition, the ASCI will use stream algal communities.

Draft versions of the core technical components of the ASCI will be presented in September to the project’s scientific advisory committee. The technical pieces already have been presented to stakeholders.

The ASCI scoring tool will complement the CSCI by providing an additional line of evidence for conducting stream bioassessments. Algae are sensitive to a different combination of water-quality stressors than are bottom-dwelling macroinvertebrate communities, underscoring the value of both tools to stream managers.

The ASCI is being developed to integrate algae taxonomic data obtained through both traditional morphological analysis and DNA sequencing methods. This approach is intended to ensure the long-term utility of the algal index.