Bioassessment Research Plan

View SCCWRP’s full thematic Research Plan for Bioassessment (PDF)

2022-2023 Executive Summary

Biological assessment, or bioassessment, is the science of evaluating the health of an ecosystem by assessing the organisms that live within it. In aquatic ecosystems, algae and invertebrates serve as particularly useful indicators of ecosystem health because they are relatively sessile and live along bottom habitats where chemical and other stressors often concentrate. Unlike traditional chemistry-based monitoring, which provides only limited information about a relatively narrow portion of the environment at a discrete point in time, bioassessment accounts for living organisms exposed to multiple chemicals and other stressors (such as altered habitats and changes in life-sustaining water-flow patterns) over extended time periods. Consequently, bioassessment has the potential to provide a more integrated reflection of the condition of an aquatic ecosystem; bioassessment also is more closely tied to environmental managers’ end-goal focus on ecosystem protection and serves as an important way to monitor and protect the populations of endangered species and fisheries. SCCWRP is focused on developing an overall bioassessment framework (e.g., survey design, interpretation methods) and associated tools that environmental managers can use to assess the health of aquatic ecosystems and inform regulatory and management decisions. SCCWRP has made considerable progress on developing bioassessment tools for streams, wetlands and marine environments for a subset of organisms, including benthic invertebrates, fish and algae. SCCWRP is also developing molecular methods for assessing each of these communities individually as well as interactions between communities. SCCWRP’s goal is to develop bioassessment tools for all aquatic habitats using a wide variety of organisms, as different organisms are uniquely suited to evaluate specific habitats.

SCCWRP’s bioassessment work revolves around four main research areas: (1) condition assessments, which encompasses developing multiple bioassessment tools and methods to evaluate and quantify the condition of multiple water body types; (2) development of molecular methods, eDNA in particular, to more cost-effectively conduct condition assessments, (3) causal and protective assessments, which encompasses applying bioassessment data and analyses to diagnose potential causes of water body impairment and vulnerabilities of healthy waterbodies to future impairment, and (4) bioassessment targets for improved water body health, which encompasses establishing scientifically defensible, quantitative benchmarks and targets for maintaining and/or working toward attainment of beneficial-use goals. To ensure condition and causal assessments are used to guide management decision aimed at improving overall condition, SCCWRP develops synthesis and integration tools that can translate and interpret bioassessment data and findings to actionable information. In particular, SCCWRP focuses on developing bioassessment interpretation frameworks to help managers understand how to use bioassessment results to inform decision-making, and how to connect bioassessment results to designated beneficial uses for water bodies.

This year, SCCWRP will continue to develop, refine, and expand its capacity to conduct both condition assessments and causal/protective assessments, as well as pursue development of guidance and decision support tools to inform management actions. SCCWRP’s focus for 2022-2023 will be on:

  • Condition assessment: Building on past successes in developing bioassessment indices for freshwater and marine ecosystems, SCCWRP will focus on adapting these indices for climate change, and continuing development of bioassessment indices for priority habitats, including ephemeral streams, lakes and estuaries. SCCWRP also will continue to expand assessment tools to focus more on ecosystem function and on refining the interpretation of bioassessment information for modified aquatic systems, both within Southern California and in other parts of the state.
  • Integration of molecular methods: Building on more than a decade of collaborative development of molecular methods, SCCWRP will focus on continued development and integration of molecular methods into monitoring and assessment programs. We will focus on using environmental DNA (eDNA) analysis, DNA metabarcode sequencing and quantitative PCR (qPCR), as a rapid, cost-effective augment to traditional microscopic taxonomy for fish, benthic algae, and stream vertebrates. A focal area this year will be improving ability to interpret eDNA signals through better understanding of fate and transport and decay processes.   Finally, SCCWRP will explore new ways to interpret and synthesize data from multiple indicators, such as multi-trophic network models, that can provide better insights about ecosystem function and beneficial use support than single-indicator assessments.
  • Linking conditions to stressors: SCCWRP will continue to evaluate the relationship between biological condition measures and stressors (ranging from conventional pollutants such as chloride, to new and emerging pollutants) to help managers set stressor levels that will protect aquatic life. These relationships are foundational to SCCWRP’s ability to develop tools that make causal assessment a reality and an integrated part of routine monitoring. For example, SCCWRP is developing prototype Rapid Screening Causal Assessment tools that include a web-based dashboard to enable application/interpretation of bioassessment data. These tools and their data interface will speed up the traditionally time-consuming process of analyzing stream bioassessment data to pinpoint which stressors are responsible for poor stream condition. SCCWRP also will continue developing a framework to link causal assessment results with specific management actions to improve water body condition. Finally, SCCWRP will work toward developing tools that use bioassessment data to support protective management actions, including identifying water bodies that have high conservation value and water bodies that are healthy but vulnerable to future stressor exposure.
  • Supporting applications to management: Perhaps the greatest obstacle to using biological data is their relative complexity compared to other types of monitoring data. To get around this obstacle, SCCWRP is developing tools capable of high-level syntheses of complex data sets, while also supporting deeper investigations for audiences requiring high levels of detail about their biological monitoring data. This work will be mainly accomplished through improved data science tools, such as easily understood data interfaces and automated report cards that advance open science principles, including analytical transparency and repeatability, as well as clear communication of results. Finally, SCCWRP will continue to support the consistent production and use of bioassessment data through the development of protocols for standardizing monitoring data, and through participation in workgroups focused on these goals. This includes development of web-based and video training materials that facilitate consistent application of bioassessment tools.