Bioassessment Research Plan

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

2020-2021 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 – independently of when stressor sampling may or may not occur. Bioassessment organisms also have differential sensitivity to various stressors, making possible focused forensic evaluations that tease apart which of the many stressors that can impact an aquatic ecosystem are the most managerially relevant. SCCWRP is focused on developing an overall bioassessment framework (e.g., survey design, interpretation methods) and associated tools to empower environmental managers to reliably and robustly use bioassessment to inform regulatory and management decisions linked to ecosystem health. SCCWRP’s vision is that bioassessment can serve as the essential tool for monitoring and managing diverse water body types across California and beyond.

Already, SCCWRP has made considerable progress developing bioassessment tools for streams, wetlands and marine environments that utilize a subset of bioassessment organisms, including benthic invertebrates, fish and algae. SCCWRP is continuing to work to provide managers with tools for comprehensive, headwaters-to-oceans bioassessments. This work includes development of multiple indicators for all priority habitat types (e.g., wadeable streams, estuaries, soft-bottom coastal waters) that cover a range of trophic levels and that characterize extent, structure and function of water bodies. To realize these goals, 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 working 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 2020-21 will be on:

  • Condition assessment: Building on past successes 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 and estuaries. In addition, SCCWRP will explore molecular methods such as DNA barcoding as a rapid, cost-effective alternative to laborious microscopic taxonomy for generating biological data that are traditionally challenging to assess (e.g., ichthyoplankton, benthic algae, and stream vertebrates). Finally, SCCWRP is exploring new ways to interpret and synthesize data from multiple indicators, such as ecological 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 focus on developing tools to make rapid causal assessment a reality and part of routine monitoring practices. One pathway SCCWRP is pursuing is development of stressor-diagnostic indicators based on life history traits and on molecular tools (e.g., RNA transcription as a measure of toxic stress). SCCWRP also will 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 stress.
  • 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, and 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 algorithms and development of easily understood dashboards and automated report cards – all utilizing open science principles to increase transparency. 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 around these goals.