Citation:

Ebersole, Joe AND M. Snyder. Fish everywhere, all the time: modeling fish in the riverscape. Coho Salmon Recovery workshop, Portland, OR, September 07, 2017.

Impact/Purpose:

State and federal agencies in the Pacific Northwest are exploring ways to improve effectiveness of salmon habitat monitoring. The Oregon Dept. of Fish and Wildlife (ODFW), National Oceanic and Atmospheric Administration (NOAA), EPA and partner organizations have learned a great deal about the condition of Oregon Coast coho streams and watersheds through monitoring and research. Partner agencies are hoping to better support management decisions around coho salmon recovery and persistence by thinking about the status of current habitats and the range of plausible futures, simulating different management action scenarios, identifying refuge habitats, and understanding the magnitude of threats in a model-based context. This talk will summarize EPA research on Oregon coastal watershed habitats and fish populations and relate what we’ve learned to ongoing research that is examining watershed resilience and recovery potential. Specifically, we will present modeling tools being developed and implemented by EPA that can help inform habitat and population monitoring and recovery planning. This Presentation contributes to SSWR 3.01C.

Description:

From 2002-2006, EPA’s Western Ecology Division conducted innovative research on the population dynamics of fish within an entire stream network. Employing individual tagging and tracking technology, we examined spatial patterns of juvenile coho salmon (Oncorhynchus kisutch) overwinter survival and size across an extensive stream network, and related observed patterns to stream habitat characteristics that varied seasonally and among different parts of the watershed. This work provided several important findings, including: 1) the under-appreciated role of intermittent streams, 2) the importance of seasonal movement to coho salmon population dynamics, and 3) the chronic effects of summer rearing conditions, high water temperatures, and parasite loads on survival and health of fish through the following winter and spring. These findings highlighted the need to better incorporate both spatial and temporal variability into both watershed and population models. Toward that end, EPA is continuing work to develop and apply watershed models that capture important seasonality, and population models that allow incorporation of important spatial structure. These models include broad classification schemes (Hydrologic Landscapes), hydrologic process models (VELMA), fish assemblage models (SMURF), and individual-based models (HEXSIM). We will briefly describe these tools and potential applications to population modeling and habitat monitoring for Oregon Coastal Coho Salmon.

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