View SCCWRP’s full thematic Research Plan for Bioassessment (PDF)
2023-2024 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 policies intended to protect water body health.
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 2023-2024 will be on:
Expanding capacity to assess different waterbody types: Building on past successes developing bioassessment indices for freshwater and marine ecosystems, SCCWRP will focus on developing capacity to use bioassessment tools to assess other waterbody types, such as seagrass meadows, ephemeral streams, lakes, and estuaries. This research involves the development of sampling methods, taxonomic standardization protocols, creation of indices or other interpretive tools, data management improvements and training programs.
- Integration of molecular methods: Building on more than a decade of collaborative development of molecular methods, SCCWRP will continue to focus on the development and integration of molecular methods into monitoring and assessment programs. SCCWRP will further develop the use of environmental DNA (eDNA) technologies – including DNA metabarcode sequencing and quantitative PCR (qPCR) – as rapid, cost-effective molecular methods to augment traditional monitoring for priority taxa, such as invasive and endangered species, bioindicators such as benthic algae and macroinvertebrates, and harmful toxigenic algae. In addition to developing molecular methods for collecting and analyzing eDNA, SCCWRP will also be working to better understand fate and transport dynamics of eDNA in the environment, including eDNA shedding and decay rates. Finally, SCCWRP will explore new ways to interpret and synthesize data from multiple indicators, such as multi-trophic network models and functional gene assays, to improve understanding of ecosystem function and evaluate how they support policies aimed at protecting water body health.
- 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. Ongoing efforts focus on linking measures of biointegrity to indicators of eutrophication, freshwater salinization, and temperature alteration. Through the development of response models, managers can set targets for improving conditions in freshwater and marine ecosystems.
- Enhancing causal and protective assessment: SCCWRP’s bioassessment research not only facilitates the detection of waterbodies in poor biological condition, but it also helps identify stressors causing the impacts. For example, SCCWRP will continue to expand prototype Rapid Screening Causal Assessment (RSCA) tools that facilitate automated analysis of regional monitoring data to diagnose likely causes of poor conditions at sites of interest; this expansion will include additional stressors, such as hydrologic alteration, water or sediment toxicity, and invasive species. In addition, SCCWRP is developing 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, 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. For both causal and protective assessment tools, SCCWRP research will expand efforts to incorporate environmental justice concerns to ensure that managers can prioritize their activities in equitable ways that benefit underserved communities.
- 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.
