Bioassessment Research Plan

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

2018-2019 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 tend to be concentrated. Unlike traditional chemical-based monitoring, which provides only limited information about a relatively narrow set of environmental stressors at a discrete point in time, bioassessment integrates exposure of living organisms to multiple chemicals and other stressors (such as altered habitats and changes in life-sustaining water-flow patterns) over extended time periods. Consequently, bioassessment provides a more comprehensive reflection of the condition of an aquatic ecosystem; bioassessment also is more closely tied to environmental managers’ focus on ecosystem protection. 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’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 three main research areas: (1) assessing the condition of different water body types using multiple indicators, (2) identifying potential causes of poor condition and vulnerabilities to healthy resources, and (3) using the data to support management activities, such as prioritization and effectiveness assessments. To assess condition, SCCWRP develops standardized sampling protocols, characterizes reference conditions, and develops assessment tools that transform complex biological data into simple measures of condition. Additionally, SCCWRP focuses on creating appropriate interpretive frameworks for understanding bioassessment outcomes, including connections to beneficial uses, and for incorporating multiple indicators into integrative assessments. To identify potential causes of degraded condition, SCCWRP uses causal assessment, a process that relies on creating rigorous evaluation procedures to understand the relationships between stressors and condition. The goals of SCCWRP’s causal assessment research are to: (1) develop causal assessment diagnostic indicators via traits-based analysis and molecular methods, (2) improve stressor measurements such as habitat condition indices, (3) explore relationships between stressors and biological responses, such as flow and nutrient responses, and (4) investigate the relative constraints on biological condition that come from different natural and anthropogenic sources. To ensure condition and causal assessments are used to guide management decisions aimed at improving overall condition, SCCWRP develops synthesis and integration tools that can translate assessment results to actionable information. In this way, SCCWRP products can be used to protect healthy waterbodies and effectively reverse the historically negligible role that biological data have played in informing key management decisions, such as designation of new conservation areas and selection of sites for restoration.

This year, SCCWRP will continue its work to develop, refine and expand its capacity to conduct both condition assessments and causal assessments, as well as pursue development of guidance and decision support tools to inform management actions. SCCWRP’s focus for 2018-19 will be on:

  • Condition assessment: SCCWRP is working to develop a broad suite of condition assessment tools, with a long-term goal of having bioassessment tools based on invertebrates, algae, vertebrates or molecular indicators that can be applied in streams, wetlands, coastal lagoons, and/or ocean ecosystems. This year, SCCWRP will focus on finalizing a statewide stream condition index for algae, a critical bioassessment indicator for evaluating impacts from nutrients, flow, temperature and habitat alteration. The new algal index, known as the Algal Stream Condition Index (ASCI), will directly incorporate molecular data into the index development process for the first time. SCCWRP is also continuing its development work on bioindicators for ephemeral streams (i.e., streams that flow for short durations immediately following rain events), where a lack of tools precludes assessment. SCCWRP is also exploring how to develop additional species, including freshwater fish and ichthyoplankton (larval marine fishes), as new bioindicators of water body condition. Ichthyoplankton holds tremendous promise because of next-generation measurement methods, including genetic barcoding, that are allowing scientists to link water quality and natural resources to the California Cooperative Fisheries Investigation (CalCOFI), one of the longest-running fish monitoring programs in the nation. Additional work will be started this year to develop environmental DNA (eDNA) methods for vertebrate monitoring and for assessing biological communities associated with eelgrass beds.
  • Causal assessment: To identify potential causes of degraded condition, SCCWRP applies and adapts the U.S. EPA’s Causal Analysis/Diagnosis Decision Information System (CADDIS) framework. This year, SCCWRP will continue to work toward developing an integrated and tiered approach to causal assessment. Rapid causal screening tools are being tested to achieve a streamlined approach for identifying major classes of stressors (e.g., flow vs. habitat alteration vs. contaminants). This will be followed by development of stressor-specific metrics based primarily on life history traits and molecular assessment tools, as appropriate, that are designed to improve diagnostic ability. This framework is being demonstrated through ongoing case studies that provide roadmaps for broader implementation of the tools throughout the region and state.
  • Integration and implementation: Although SCCWRP’s research on condition and causal assessment provides the technical foundation to support management decisions, this technical foundation must be informed by the development of guidance and decision support tools. SCCWRP is conceptualizing (1) tools that will allow for the development of report cards and similar data synthesis methods, (2) decision support tools that help locate high-value areas for protection and prioritize management actions, and (3) screening tools that help evaluate the restoration potential of degraded water bodies and establish appropriate management targets.