Assessing fish habitat, productivity, and nutrient enrichment in the Henry’s Fork River Headwaters
Date:
August 2018-August 2022
Abstract:
Macrophytes and strong trout fisheries overlap at a surprising frequency, yet the connections between macrophytes and fish habitat for ecologically, economically, and culturally important trout populations remain uncertain. The Henry’s Fork of the Snake River in east Idaho is one such river with healthy macrophyte beds and a world-class trout fishery. The goal of this project is to reduce uncertainty about the relationship between macrophytes and trout habitat both within the Henry’s Fork system and in other large rivers in general. We are starting at the microhabitat scale and: 1) study fish habitat selection to understand what habitats trout prefer in macrophyte containing streams and 2) utilize bioenergetics to investigate potential mechanisms behind fish habitat selection. Next, we will shift to the reach scale to 3) connect macrophyte growth, nutrient fluxes, and productivity, and 4) investigate the potential role of lake-based migratory fish, allowing us to understand potential controls on fish habitat availability, quality, and fishery productivity. Methods will include observational comparative studies among different reaches of the Henry’s Fork, snorkel and physical habitat surveys, drone imagery, and use of a long-term water quality monitoring dataset. Our results will aid resource managers by supplying information on the drivers of fish habitat availability and quality in the Henry’s Fork ecosystem and other macrophyte-rich riverine fisheries.
Funding:
- Henry’s Fork Foundation
- Utah State University Department of Watershed Sciences
- Utah State University – The Ecology Center
- Western Division AFS
- Idaho Fish and Game
- Reservoir Fish Habitat Partnership
- U.S. Geological Survey – Utah Cooperative Fish and Wildlife Research Unit (In-kind)
- The Ecology Center at Utah State University
Investigators:
- Jack McLaren, PhD candidate
- Dr. Phaedra Budy, USGS UTCFWRU, USU-Watershed Sciences, Ecology Center
- Dr. Soren Brothers
Other Collaborators:
- Dr. Rob Van Kirk
A large rainbow trout (Oncorhynchus mykiss) in clear water positioned just upstream of a macrophyte bed in such a way as to utilize the hydraulic “cushion” created by the macrophytes as resting and feeding habitat.
Jack McLaren holding a quality female Kokanee Salmon (Oncorhynchus nerka) during fall field season in the Henry’s Fork upstream of Island Park Reservoir.
