Resources unveiled to boost utility, accessibility of stream bioassessment data statewide

SCCWRP has unveiled a comprehensive set of resources intended to overcome common end-user challenges associated with analyzing, accessing and interpreting stream bioassessment data – challenges that have stymied more widespread adoption of bioassessment in watershed management programs.

The resources, developed over the past year, will enable managers with limited training in statistical analysis and data interpretation methods to transform raw field bioassessment data into clear, managerially relevant insights. In recent years, as bioassessment analyses have been integrated into routine stream monitoring programs statewide, many end users have struggled with data analysis and interpretation.

The management-friendly resources include, among other things, step-by-step technical guidance on calculating stream bioassessment scores for users with limited familiarity with the R programming language, as well as practical advice on navigating site-specific considerations and challenges that can complicate analysis and interpretation of stream bioassessment data in the real world.

The resources also include a beta version of a web-based data portal that centralizes bioassessment data and offers built-in automations.

Bioassessment data, which provide insights into the various biological components of an aquatic ecosystem, are becoming an increasingly integral, routine part of assessing the health of wadeable streams statewide.

Over the past few years, SCCWRP and its partners have developed a trio of statewide assessment tools – the California Stream Condition Index (CSCI), the Algal Stream Condition Index (ASCI) and the Index of Physical Habitat Integrity (IPI) – to quantitatively score the health of wadeable streams. Although these statistically based predictive indices have become a foundational component of stream monitoring statewide, the tools can be technically difficult to use to produce high-quality analyses. Stream managers also have struggled to locate and integrate all of the data they need to perform bioassessment-based analyses.

Because bioassessment expertise has to date been concentrated among a limited number of experts, bioassessment data are prone to being misinterpreted by inexperienced users. For example, managers may misattribute poor bioassessment index scores to water quality degradation alone, when drought impacts are likely to be contributing factors.

In response, SCCWRP worked with the State Water Resources Control Board and multiple end-user groups to develop three key resources for increasing the utility and accessibility of bioassessment tools:

» SOP for calculating index scores: SCCWRP in October completed a comprehensive SOP document that walks end users through step-by-step instructions for using the CSCI and ASCI to calculate stream bioassessment scores. The SOP also includes instructions for calculating IPI, often used as a complement to the CSCI and ASCI in understanding the overall ecological integrity of a stream site. This SOP – available on the State Water Board’s Surface Water Ambient Monitoring Program (SWAMP) bioassessment data tools page – unifies and builds upon multiple SOPs that were previously published individually.

» Decision framework for interpreting scores: SCCWRP published a document last spring that provides guidance on how to properly interpret and report bioassessment scores when faced with complicating factors, such as having bioassessment data where a relatively low number of organisms were sampled, or deciding whether to attribute low scores to stressors caused by human activities vs. natural environmental conditions. These real-world considerations also extend to how to interpret the results of the Stream Classification and Priority Explorer (SCAPE), a SCCWRP-developed tool that predicts where managers are more vs. less likely to find success in improving stream condition. The guidance was originally developed for use in the San Gabriel River watershed, but is applicable across Southern California and beyond.

» Web data portal: SCCWRP in October unveiled a beta version of a web-based data portal that centralizes all bioassessment data generated by the Southern California Stormwater Monitoring Coalition (SMC). The user-friendly portal eliminates the need for stream managers to query up to three different databases to access bioassessment data. The portal also automatically calculates bioassessment scores, eliminating the need for multiple end users to independently calculate scores for a single site. Finally, the portal paves the way for the development of management-friendly dashboards and other data visualization tools for stream bioassessment data across Southern California.

SCCWRP will continue to refine and expand all of these bioassessment resources in the coming years in response to user feedback.

For more information, contact Dr. Susanna Theroux or Dr. Raphael Mazor.