Coloring in the Lines: Mapping surface water presence in a rapidly changing climate
Wednesday, October 20, 2021
1:00 pm Eastern Time
The Russian River historically provided habitat for tens of thousands of anadromous fish, including coho salmon (O. kisutch), whose populations have declined drastically as a result of habitat loss and degradation. Significant population declines in the Russian River and other central California rivers led to the designation of the Central California Coast (CCC) evolutionarily significant unit (ESU) of coho salmon as an endangered species at the state level in 2002 and the federal level in 2005. State and federal recovery plans have been developed for the CCC ESU of coho salmon and the Russian River is a focal point of recovery efforts. In 2004, the Russian River Coho Salmon Captive Broodstock Program (Broodstock Program) began releasing juvenile coho salmon into tributaries of the Russian River with the goal of re-establishing populations that were on the brink of extirpation from the watershed. The Russian River Salmon and Steelhead Monitoring Program (RRSSMP) emerged through the collaborative efforts of federal, state, and local Broodstock Program partners. Under the direction of California Sea Grant—a unique collaboration between the National Oceanic and Atmospheric Administration, the State of California and universities across the state, including Scripps Institution of Oceanography at UC San Diego—RRSSMP tracks the abundance, survival, and distribution of wild and hatchery-released fish in order to inform adaptive strategies for the Broodstock Program and to identify factors limiting the recovery of Russian River salmonid populations.
Like the majority of global streams, many Russian River tributaries are intermittent and experience low summer streamflow that leads to the isolation of pools or the complete drying of the streambed. We developed wetted habitat surveys as a way to document the impacts of stream drying on salmon and steelhead. Wetted habitat surveys are conducted during the dry summer months (May-October) to map the presence of surface water in salmon-rearing tributaries. Documenting the extent and timing of stream drying, as well as water temperature and dissolved oxygen conditions in remaining pools, helps us to inform the management of fish populations and water resources in these important salmon streams.
Comparing wetted habitat and fish distribution data has allowed us to estimate the impacts of water scarcity on threatened and endangered fish populations, particularly during the recent historic droughts. Through our work, we have identified low summer streamflow as the biggest single bottleneck to salmonid recovery in the Russian River basin. Data from wetted habitat surveys have also been used by partner agencies to identify potential habitat and streamflow enhancement project sites, rescue stranded coho salmon, and guide the juvenile coho stocking efforts of the Broodstock Program. Though the number of returning adult coho salmon has increased from less than 10 to an average of 400 to 500 a year in the last decade, there is a long way to go to reach the recovery target of >10,000 individuals. Wetted habitat surveys have proven to be a useful, straightforward monitoring technique that are invaluable for making management decisions in the context of recovery targets.
Elizabeth Ruiz (they/them/theirs)
From the Hudson to the Russian River, Elizabeth has been working to conserve freshwater ecosystems since 2012. After receiving a bachelor’s degree in biology from Vassar College, Elizabeth moved back to their home state of California to do science at the intersection of people, water, and salmon. As a fish biologist with the Russian River Salmon and Steelhead Monitoring Program they conduct salmonid life cycle monitoring, contribute to outreach efforts, document water quality conditions, and lead summer habitat projects.
Despite being raised in the Russian River region, Troy traveled halfway around the world before finding his focus on salmonids in California. Troy graduated from Massey University in New Zealand with a Bachelor of Science in Environmental Science & Geography. After working in the environmental restoration field, Troy joined the Russian River Salmon and Steelhead Monitoring Program as an AmeriCorps Watershed Stewards member. Today Troy conducts year-round fieldwork monitoring endangered salmonids and specializes in summer habitat surveys as a staff biologist for the program.