The Kvichak and Nushagak watersheds support some of the largest sockeye salmon runs in Bristol Bay, which is the largest sockeye salmon producing region in the world. Stream habitats in these watersheds support all five species of Pacific Salmon in addition to at least 24 other resident and anadromous fish species. These valuable fishery resources are under threat from both mining and climate change. The goal of this project is to characterize reference conditions, defined as the expected current condition of unimpaired streams, to use as a benchmark for detecting future changes in key indicators of first through fourth order streams of the Nushagak and Kvichak Rivers. Indicators were chosen to detect important changes in aquatic habitats expected to potentially arise due to impacts from mining development or from climate change. The project expands on previous targeted monitoring efforts in the region by providing a statistically sound basis for inference to the broader region and improving resolution in space and time.

About the Data
In 2015, a generalized random tessellation study design was used to probabilistically select and sample 30 sites from all first through fourth order streams in the Lime Hills ecoregion of Bristol Bay. An additional ten sites were sampled strategically. Data collection in 2015 included a detailed water chemistry suite, physical habitat measurements, macroinvertebrates, diatoms, and fish. Five probabilistic and five strategic sites were sampled annually from 2016-2019 for selected indicators. The Information on Data Files.docx includes additional information on each dataset.

Acknowledgements
Project funders included the Southwest Alaska Salmon Habitat Partnership, the Bristol Bay Heritage Land Trust, the Alaska Department of Environmental Conservation, the National Fish and Wildlife Foundation, the World Wildlife Fund, the Center for Science in Public Participation, the U.S. Fish and Wildlife Service, the Bureau of Indian Affairs, and the Nondalton Tribal Council. We are grateful to Tim Troll for supporting our research objectives and soliciting funding support for this project. We would like to thank Stan Hermens with Hermens Helicopters for safely transporting field crews each summer.