Bioassessment Research Plan

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

2021-2022 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, certain organisms serve as particularly useful indicators of ecosystem health because they integrate conditions at a site over time. In this way, these organisms can directly measure management effectiveness at protecting aquatic life and other designated beneficial uses for water bodies. Organisms used in bioassessment commonly have limited mobility and cannot escape the stressors affecting them (e.g., algae, bottom-dwelling invertebrates). Thus, these organisms integrate the effects of chemical contaminants, habitat alteration and other non-chemical stressors over time. Different biological assemblages also have different sensitivities to individual stressors, allowing focused forensic evaluations that can identify causal impacts. SCCWRP is focused on the development of a comprehensive bioassessment framework, including survey design tools and interpretation methods, that empowers environmental managers to use bioassessment data to inform regulatory and management decisions. SCCWRP’s vision is that bioassessment can serve as the foundational tool for monitoring and managing diverse water body types across California and beyond.

SCCWRP has successfully developed bioassessment tools for streams, wetlands and marine environments that rely on an assortment of bioassessment organisms, including benthic invertebrates, fish, and algae. Additionally, SCCWRP is developing tools for comprehensive, headwaters-to-oceans bioassessments, including the development of novel indicators for priority habitat types (e.g., wadeable streams, estuaries, submerged aquatic vegetation, and soft-bottom coastal waters) that cover a range of trophic levels and that can serve as indicators of the functional health of water bodies. To support these efforts, SCCWRP is leading research projects in three broad areas: (1) assessing condition and support for beneficial uses by examining biological organisms, populations, communities and processes; (2) linking conditions to manageable stressors, both for water bodies in poor condition (i.e., causal assessment) and good condition (i.e., protective assessment); and (3) supporting the application of bioassessment data to management decisions (e.g., improving data access and interpretation).

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 2021-22 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. There will be a particular emphasis this year on refining the interpretation of bioassessment information for modified aquatic systems, both within Southern California and in other parts of the state. In addition, SCCWRP will continue to explore molecular methods, including DNA metabarcode sequencing and quantitative PCR (qPCR), as a rapid, cost-effective alternative to traditional microscopic taxonomy for fish, benthic algae, and stream vertebrates. Finally, SCCWRP is exploring 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 manageable 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 will also develop a framework to link causal assessment results with specific, practical 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.