Bugs as Barometers: Invertebrates Help Measure Wetland Health
The Port of Portland began working with the Xerces Society, a Portland-based nonprofit dedicated to conservation of invertebrates and their habitat, in 2008. The Xerces Society used the Port’s wetland mitigation sites for research on wetland invertebrates, including insects such as dragonflies, mayflies, caddisflies, and beetles. Scientists from the organization conducted field surveys throughout the Willamette Valley to develop a biological assessment tool that evaluates the health and function of Pacific Northwest wetlands. The project also received support from the U.S. Environmental Protection Agency and Oregon Watershed Education Board.
For the Port, the tool will be a valuable resource for monitoring wetland mitigation sites and helping to determine whether mitigation efforts have improved wetland biological function. The results have already been gratifying to Port natural resources staff. According to Celeste Mazzacano, Ph. D., a staff scientist with the Xerces Society, “The Port’s Randall mitigation site was our dragonfly bonanza—the winner for dragonfly and damselfly diversity.”
Though the biological assessment tool research is complete, the Port and the Xerces Society continue to work together at the Port’s mitigation site on Government Island. The Xerces Society assisted the Port in developing the grassland mitigation plan and selecting plant species that will be seeded on the site. Many of the plant species were specifically selected to provide a pollen and nectar source throughout the year for pollinators. The Xerces Society will conduct pollinator surveys to evaluate the richness, abundance, diversity, and composition of native pollinators before and after native grassland enhancements and invasive plant removal.
Carrie Butler, Mitigation Site Manager, 503.415.6319
Port of Portland Mitigation Sites