US EPA

EPA announced the availability of the final report, Implications of Climate Change for State Bioassessment Programs and Approaches to Account for Effects. This report uses biological data collected by four states in wadeable rivers and streams to examine the components of state and tribal bioassessment and biomonitoring programs that may be vulnerable to climate change. The study investigates the potential to identify biological response signals to climate change within existing bioassessment data sets; analyzes how biological responses can be categorized and interpreted; and assesses how they may influence decision-making processes. The analyses suggest that several biological indicators may be used to detect climate change effects and such indicators can be used by state bioassessment programs to document changes at high-quality reference sites.

This report is intended for managers and scientists working on biological indicators, bioassessment, biomonitoring, and biocriteria, particularly in the EPA’s Office of Water and Regions, and also at state agencies. The report uses biological data collected by four states – Maine, North Carolina, Ohio and Utah – shallow or wadeable rivers and streams. The biological data are aquatic insects, clams, shrimp-like organisms, and worms known as benthic macroinvertebrates. These organisms are important biological indicators used to assess the condition of waterbodies.

This report shows that some of these biological indicators are more sensitive to changes in water temperature than others. While these indicators can be useful in determining effects related to climate change, they can also confound measurements that have traditionally been used to signal impairment to a stream or river. Because of this, it is not always clear whether changes in biomonitoring data are affected by climate change or other stressors. One way to distinguish these effects is through long-term monitoring of high-quality, generally undisturbed rivers and streams. Current monitoring is not designed to detect the effects of long-term changes in water temperature or streamflow on benthic macroinvertebrates or other organisms in rivers and streams. A more comprehensive monitoring design would enhance the ability of water program assessments to understand if climate change or other stressors is causing changes in biomonitoring data. This final report provides a foundation for understanding if biological indicators that are used to provide a signal of stream or river impairment are vulnerable to changes in climate. It also provides insight into how the effectiveness of monitoring and management plans can be maintained under changing climatic conditions.

The study investigates the potential to identify biological response signals to climate change within existing bioassessment data sets; analyzes how biological responses can be categorized and interpreted; and assesses how they may influence decision-making processes.

U.S. EPA. Implications of Climate Change For State Bioassessment Programs and Approaches To Account For Effects (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/036F, 2012.