Workshop on Predicting Salmon Habitat in Alaska

The goal of this workshop was to advance the development of valid models for predicting salmon habitat distribution in Alaska in order to expand the coverage of the Anadromous Waters Catalog (AWC) by:(1) Enhancing Alaska Department of Fish and Game (ADFG) and TNC’s knowledge and ability to use spatial models; (2) Improving the capability of ADFG to effectively survey potential habitat; (3) Providing information for ADFG to gain funding support for their program to expand the AWC.

Alaska’s Wild Salmon Management

Alaska is the last stronghold for Pacific salmon in North America. Most other salmon populations along the Pacific Coast have drastically declined. The State’s Constitution mandates management of wild salmon to provide sustained yields. By law, the mission of the ADFG is to protect, maintain, and improve the fish, game, and aquatic plant resources of the state, and manage their use and development in the best interest of the economy and the well-being of the people of the state, consistent with the sustained yield principle. To sustain production, salmon spawning, rearing and migratory habitat must be protected. The principal legal tool in Alaska for protecting salmon habitat is the AWC. Only when a stream that has salmon is formally listed in the AWC does it receive the full statutory protection afforded under AS41.14.870.

Alaska’s Geographic Scope

Alaska’s 1.5 million km of streams makes it extremely difficult logistically in most portions of the State to obtain on-the-ground salmonid habitat information. The AWC has documented anadromous fish in about 16,552 streams throughout Alaska. On average, less than half of the streams that exist on the ground are actually delineated on a map and fewer yet are documented for presence or absence of the various fish species.

Resource managers need to know where important aquatic habitats exist, and which waterbodies contain anadromous species in order to ensure their adequate protection. Traditional remote-sensed data products (e.g. stereo aerial photography) used to map and update the hydrography across Alaska are often limited by the terrain and dense vegetation in delineating the numerous smaller tributary streams. These small unmapped systems are often vitally important habitats for various lifestages of both resident and anadromous salmonid species. The problem simply stated is that conservation measures, such as provided by the AWC, cannot be applied to these streams until they are surveyed and anadromous fish presence is documented.

The threat of increased development coupled with the constraints of difficult logistics and the limited knowledge on the distribution of salmon habitat have heightened the need to predict the distribution of salmon in Alaska’s unsurveyed freshwaters in a timely and efficient method.

Photos and GIS mapping by Mike Wiedmer.

Sessions

• Executive Summary, Agenda, Abstracts  
• Session I: Alaska's Wild Salmon Program
• Session II: Existing Approaches
• Session III: Statewide Spatial Datasets
• Session IV: Geospatial Tools for Estimating Salmon Distribution
• Session V: Statistical Approaches and Field Sampling Design

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