Algae-based stream scoring tool to be finalized this fall

An assessment tool that will score the ecological health of California wadeable streams by analyzing algal communities is scheduled to be finalized and published as early as this fall.

The Algal Stream Condition Index (ASCI) will complement the California Stream Condition Index (CSCI) by providing an additional line of evidence for conducting stream bioassessments, and will help form the technical foundation for a proposed statewide stream biointegrity-biostimulatory policy.

An expert science panel is scheduled to review and provide final feedback on the ASCI this summer; public comments also will be solicited.

The ASCI will make use of algae taxonomy data obtained via both DNA sequencing methods and via traditional morphological analysis under a microscope.

The work builds off algae-based stream scoring tools known as Algal Indices of Biotic Integrity, which SCCWRP co-developed about five years ago for use in coastal Southern California.