Identifying Benthic Macroinvertebrates for Assessment of Riverine Habitats

Presenter: Belle Ehrmantraut

Co-Presenter(s):
Daniel Pejoro, Sydney Pontius, Logan , Kelsey Dowdall

Presenter Status: Undergraduate student

Academic Year: 22-23

Semester: Spring

Faculty Mentor: Nick Geist

Department: Biology

Funding Source/Sponsor: Koret Scholars Program

Other Funding Source/Program: CEI

President's Strategic Plan Goal: Sustainability and Environmental Inquiry

Abstract:
Understanding how to accurately identify organisms is a highly effective tool for a biologist to have in their toolkit. In order to assess the water quality and overall habitat health of Copeland Creek (Sonoma County, CA), students in the Geist lab have gained these skills and applied them to identify over 1,000 benthic macroinvertebrates (BMI) collected from the local waterways within the Laguna de Santa Rosa Watershed. Identification of these invertebrates is revealing the condition of the habitats throughout the Laguna; specifically how increasing urbanization along the approximately 10-mile reach of Copeland Creek affects water quality and biodiversity.The abundance/diversity of BMI is a standard tool employed globally to assess an ecosystem health. A healthy waterway will typically provide habitat for larval phases of the life cycle of mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera, otherwise referred to as the EPT index; while urban creeks with relatively poor water quality tend to have denser populations of larval crane flies, midges, and mosquitoes, among other pollution-tolerant taxa. Rheophilic (current-loving) insects are key biological indicators and EPT presence indicates high levels of dissolved oxygen and diverse habitat conditions capable of supporting a range of other aquatic organisms. With the ongoing shift in the use of freshwater organisms/BMI to assess water quality compared to physicochemical measurements, these organisms can serve as significant biological indicators of habitat health in our vulnerable aquatic ecosystems and provide a key skill set for our students.