la waterkeeper: using biological objectives to monitor water quality
Aidan Butler | Flickr

Practicum Project | 2021

Creating Biological Objectives to monitor water quality in California

Protecting California’s water resources has never been more important. Climate change is pushing weather patterns to extremes, with scientists predicting increased floods and drought in California’s future. These events threaten the security of California’s water supply and the aquatic and terrestrial wildlife communities that rely on fresh water to survive. As water supplies diminish and aquatic ecosystems are degraded, there is an increasingly urgent need to restore the quality of existing polluted water bodies. In Southern California, 98% of streams in urban areas show signs of degradation to ecosystem health. Despite laws in place that require water quality assessments to use physical, chemical, and biological indicators, California assessments primarily rely on chemical indicators such as dissolved oxygen or nutrient concentrations. While chemical parameters are useful, they cannot be used to determine the combined effects of multiple pollutants on aquatic health. In contrast, biological indicators assess ecosystems holistically, focusing on the presence and diversity of aquatic organisms in the waters, which reflect the overall health of the water and synergistic impacts of different pollutants.

Our research with the non-profit Los Angeles Waterkeeper aims to determine if a specific stream condition rating index, known as the “California Stream Condition Index” or “CSCI,” can be used to create meaningful biological objectives for the health of waterways throughout the Los Angeles region. Los Angeles Waterkeeper’s mission is to protect and improve the ecological health of Los Angeles waterways to provide safe and accessible access to all. Research on biological indicators in the stream rating index is especially relevant to this goal. This rating index will account for the living organisms in a stream bed to drive forward restoration efforts of California’s degraded streams and waters by creating a comprehensive water quality indicator.

Client: LA Waterkeeper

Student Team; Corisa Wong, Sophia Bozone, Veronica Lu, Ayahna Mack, Colbert Manson, Francesca DePrima, Lester Diaz

Advisor: Dr. Ariel Levi Simons