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Standard Operating Procedures (SOP)

Field Collection Procedures for Freshwater Streams and Rivers

Combined Benthic Macroinvertebrates and Algae

  • Collection of Field Data for Bioassessments of California Wadeable Streams: Benthic Macroinvertebrates, Algae, and Physical Habitat (May 2016) - These documents are the combination of previous versions of the SOP's for both benthic macroinvertebrate and algae with the addition of the supplemental guidance document. These are the standard procedures designed to support general assessment of the ecological condition of wadeable streams and rivers based on the composition of the benthic macroinvertebrate and benthic algal assemblages. The procedures also produce standardized measurements of instream and riparian habitat and ambient water chemistry to support interpretation of the biological data.
    • Supplemental Guidance:
    • Field Data Sheets:
      • NEW! Bioassessment Field Data Sheets with Algae for the SWAMP v2.5 database are available. (Updated April 2022)
      • SWAMP Conversion and Data Reporting for Benthic Chlorophyll a, Pheophytin and AFDM_Algae (updated 01/26/12)
      • Note: In May 2010, SWAMP updated the document about the procedure for sampling stream algae assemblages for ambient bioassessment. There are three main updates to this document: (1) The labels for biomass and taxonomic identification have been updated to include additional information (page 20, figure 6); (2) If presence/absence of a microalgal layer cannot be determined with certainty, the scoring of microalgal thickness is now "UD" (page 39) instead of "Z"; and (3) the bioassessment field data sheets with algae are no longer included in the document. Please download the most recent version of the datasheets.

Field Collection for Freshwater Wetlands

Taxonomy Procedures

Calculating Bioassessment Indices

This document describes steps in calculating three different ecological indices used to quantity stream conditions in California based on biological and physical data. The instructions herein are provided as support for analysts requiring scores for the California Stream Condition Index (CSCI), Algal Stream Condition Index (ASCI), and the Index of Physical Integrity (IPI).
Additionally, these instructions will help analysts calculate landscape-scale measures of human activity, which are used to determine if streams meet criteria to quality as reference sites.

California Stream Condition Index (CSCI)

The California Stream Condition Index (CSCI) is a biological index used to score the condition of BMI communities in perennial wadeable rivers and streams. Developed in 2013 to include a broader reference data set and to ensure better statewide applicability than previous regional indices, the CSCI combines two unique types of index that have traditionally been used separately: an observed-to-expected (O/E) index and a multimetric index (MMI). The CSCI is the first index to provide a consistent statewide standard for interpreting bioassessment data and is the basis of the new statewide Biological Integrity Assessment Implementation Plan.

Algal Stream Condition Index (ASCI)

The Algal Stream Condition Indices (ASCIs) are biological scoring tools that help aquatic resource managers translate complex data about stream benthic algae into an overall measure of stream health. The ASCI complements the CSCI by providing an additional line of evidence for conducting stream bioassessments.

Index of Physical Habitat Integrity (IPI)

Indices of Biological Integrity (IBIs)- Archived

For most assessment applications, the CSCI should be used instead of these IBIs. The documents provided below are for informational purposes only.

Prior to the CSCI, several regional indices of biological integrity (IBIs) were developed for different portions of the state. An IBI uses multiple metrics to describe the biological condition of a stream or river. Included metrics vary by biogeographical region and benchmark values are based on reference sites considered to be relatively undisturbed by human activity.

To obtain a copy of archived IBIs, please contact shuka.rastegarpour@waterboards.ca.gov