***Funded by the Alaska Sustainable Salmon Fund #56012, a part of the Pacific Coastal Salmon Recovery Fund Synopsis During the summers and falls of 2023-24, staff from the Alaska Department of Fish and Game (ADF&G), Division of Sport Fish, Alaska Freshwater Fish Inventory (AFFI) program will conduct a rapid, systematic inventory of anadromous and resident fish distribution and associated aquatic and riparian habitat in select drainages of the Copper and Bering rivers. This proposal addresses a critical area in Alaska - adjacent to or within land units such as Wrangell-St. Elias National Park & Preserve and the Chugach National Forest - that supports significant sport, commercial, personal use, and subsistence fisheries within expansive glacial fed watersheds that are experiencing glacial retreat, potentially leading to increased stream habitat available to migratory and resident fishes. AFFI program staff will identify and survey streams most likely to expand coverage of the State of Alaska's Catalog of Waters Important for the Spawning, Rearing or Migration of Anadromous Fishes (AWC) and when anadromous fish are observed, AFFI staff will nominate those waterbodies to the AWC. Introduction In Alaska habitats that support migrating, spawning, or rearing anadromous fish are protected under state, federal, and local administrative jurisdictions. Alaska Statute (AS) 16.05.871 (the Anadromous Fish Act) is the keystone statutory protection for freshwater habitats of anadromous fish in Alaska, requiring the ADF&G to "specify the various rivers, lakes, and streams or parts of them" of the state that are important to the spawning, rearing, or migration of anadromous fish in the Anadromous Waters Catalog (AWC) and Atlas. It is important that water bodies used by anadromous fish are listed in the AWC because only listed water bodies are protected from potentially harmful activities. To be listed in the AWC, water bodies require site-specific, direct, unambiguous observations of anadromous fish by a qualified observer (Giefer and Blossom 2021a). Anadromous fish habitat protection and management in Alaska are predicated on explicit knowledge of the distribution of species and life stages. Although the AWC currently lists 20,846 total water bodies (18,772 streams, 2,074 lakes) as being important for the spawning, rearing, or migration of anadromous fish, the documented extent of these waters and their tributaries as critical habitat to anadromous life histories is far from complete. Based on current areas surveyed, this number of AWC-listed water bodies likely represents a small proportion of the total number of streams, rivers, and lakes used by anadromous species statewide. Until these habitats are inventoried, they will not be protected under Alaska’s Anadromous Fish Act. Further, as landscapes respond to climate change and glaciers retreat, the AWC may increasingly underestimate salmon habitat without focused sampling of sensitive glacial watersheds such as those draining into the Gulf of Alaska or Prince William Sound (Pitman et al. 2021). Knowing where, and when anadromous fishes and resident species use habitats in Alaska, is crucial to respond to natural or manmade disturbances, manage fisheries, mitigate development, and understand regional ecology. Without this knowledge, managers have limited ability to respond to potential shifts in species use of habitat such as those in response to glacial retreat associated with climate change. Predicted near-term impacts of glacial retreat on salmon and fish habitat may manifest in at least two major ways (Ogden 2018; Pitman et al. 2021): 1) increased upstream access for salmon populations that already use glacier-fed rivers; 2) fish community shifts whereby some streams previously devoid of fish may start supporting one or more species of salmon that stray or colonize the streams exposed and lengthened by glacial retreat. However, long-term effects of glacial retreat are less predictable to fish populations that may be affected by more dynamic hydrography in the absence of stable summer glacier-fueled flows. Additionally, mining, and other land uses in or along currently glaciated streams may also exploit newly exposed resources. In the Copper River basin and other watersheds draining into the Gulf of Alaska, salmon distributions are predicted to gain 1,000 km of accessible waters due to glacial retreat – an increase in stream habitat greater than other glaciated drainages in the Pacific Northwest (Pitman et al. 2021). Therefore, the time is ripe to establish where salmon distributions have changed in the Copper and Bering rivers within both a contemporary timeframe (e.g., comparing this study’s findings to previous extents of AWC waters from historical sampling) as well as providing a current baseline of extents for reference to future predictions of shrunken glacial coverage in the region. The knowledge provided by this research would be integral into putting glacial retreat into a regulatory context protecting significant subsistence, commercial, personal use, and sport fisheries while also providing a metric that could assess accuracy of current and future predictions of how glacial retreat will affect Alaskan salmon populations. Knowing contemporary distributions of anadromous and resident fishes is especially critical to current and future management of glacial areas such as the Copper River basin and the Bering River These watersheds support subsistence and commercial fisheries for chum, Chinook, coho, pink and sockeye salmon amid intensifying effects of climate change including permafrost or glacial thawing that has associated hydrological changes in streams. Despite cultural, ecological, and economical interest in this climate-sensitive region, the Copper River basin not been investigated for anadromous and freshwater fishes at a landscape level and consequently, current AWC coverage may underestimate salmon habitat (Bidlack et a. 2014; Giefer and Blossom 2021a). From July 20-August 1, 2023 and 2024 AFFI staff will sample fish communities using AFFI protocols in selected tributaries of lower Copper River. Sampling target survey sites will include backpack electrofishing wadeable smaller headwater streams and raft-mounted electrofishing un-wadeable medium-sized streams. This timing will maximize the ability to detect juvenile and spawning or migrating Chinook and sockeye salmon in upstream areas as well as spawning or migrating pink and chum salmon in lower reaches. Then, depending on run timing based on data from Division of Commercial Fisheries, AFFI staff will sample fish communities using aerial surveys and AFFI protocols in selected streams of the Copper and Bering rivers during late-August, September, or early October. The timing of these late-season sampling events is to maximize encounters of spawning and migrating coho salmon. Location(s) Sampling will be performed in select drainages of the Copper River with base camps enhancing access longitudinally throughout the basin (from downstream to upstream): · Cordova (60.541053, -145.757522) · Glenallen (62.108639, -145.527079) Objectives Objective 1: To maximize the spatial increase of documented anadromous fish habitats depicted in the AWC within the study area (annually sampling a minimum 72 headwater target streams, and 8 un-wadeable target streams) to reach 144 headwater site visits and 16 un-wadeable stream site visits in total across two years (160 sites total). Objective 2: To record characteristics, using established protocols, of aquatic habitats (including riparian zone) at each sampling location. Objective 3: To provide the fish distribution and associated aquatic habitat information to State & Federal agencies, participating communities, and the public. Study area selection The long-term goal of the AFFI program is to complete a statewide baseline inventory of fish assemblages and associated aquatic and riparian habitats. At its inception, the AFFI program developed a systematic approach to rank and prioritize Alaska’s 139 subbasin level hydrologic units. Subbasins were chosen because they most closely match the scale of the project study area of a typical helicopter-supported, regional baseline fish inventory. A survey priority index (SPI) of the subbasins was then developed based on; amount of past survey effort in the subbasin, removing lands considered to have adequate protection from anthropogenic degradation such as National Parks & Preserves, the ratio of current AWC coverage to the total length of all mapped streams within the subbasin, and a Human Activity Index (HAI) created by The Nature Conservancy (Feirer et al. 2006), assessing 4 types of human activities that could impact Alaska ecosystems. At the time of this proposal, the AFFI program has surveyed 91 of the 139 subbasins that were originally prioritized. This prioritization method has been documented by AFFI staff in an unpublished internal document that is available upon request. The Copper River study area drains 67,480 km2, including four subbasins (HUC8 level). The Bering River drains an additional 1,991 km2 of glaciated lands. This proposed study would add 5 subbasins to the total sampled by the AFFI program. Target stream selection This project is guided by the AFFI program’s survey site selection protocol, which uses a Geographic Information System (GIS) to rank potential survey sites across the study area based on upstream catchment area and potential mileage to be added to the AWC. Target stream selection will be initially carried out using the AFFI published method of using GIS to identify previously unsampled (or not rigorously sampled) streams that can be safely accessed and effectively electrofished while maximizing potential additions to the AWC (e.g., Giefer and Cathcart 2019). Based on past AFFI projects, it is estimated that a minimum of 72 headwater and 8 un-wadeable streams could be sampled annually by a two-person field staff during helicopter-assisted efforts in July-August (12 field days) and late August, September, or October (6 field days). However, these estimates of total sites are conservative (e.g., this equates to only 4 headwater sites per day) and contingent upon no weather or logistical problems preventing sampling. Additionally, opportunistic sampling via the road systems will be done as able. The number of headwater streams in the study area will exceed the project’s limited sampling effort capacity; therefore, a subset of mapped streams, comprising the longest stream segments not listed in the AWC will be selected as targets. The headwater team will sample on average four streams per day and, when operating, the raft or riverboat team(s) will float and sample one to two un-wadeable streams per day. Sites will be prioritized according to logistics (i.e., fuel and time needed to reach location) and potential for addition to the AWC. Further, sites within the study area that have the highest potential for habitat degradation will be identified and prioritized after consultation with local land owners (e.g., native communities), the ADF&G Habitat Section and federal land managers and biologists. Sampling methods Fish surveys using methods that can target a broad range of fish species, both anadromous and resident, are useful to identify critical habitat supporting important fish populations. Following ADF&G's AFFI protocols (Giefer and Cathcart 2019), crews will use a helicopter or boat to access streams and sample their fish communities during at least 20 days annually in 2025 and 2026. Target survey sites will include wadeable headwater streams sampled with a backpack electrofisher, and un-wadeable streams (including mainstem rivers) sampled with a raft-mounted electrofisher. At all target streams, a length of stream (referred to as a reach) standardized by stream width (i.e., 40 or 120 wetted-channel-widths in wadeable and un-wadeable target streams, respectively), will be sampled to include all aquatic habitat types within that reach. Collected fish will be identified to species, tallied, fork length measured, and examined for external abnormalities. At selected reaches, the fish community will be sampled with standardized methods and effort, according to AFFI protocols. Fish will typically be collected by single-pass electrofishing. Electrofishing is the principal fish collection gear because it is recognized as the most comprehensive and effective method for collecting fish in lotic systems. Opportunistic sampling with gillnets (especially for subsistence targeted species that have demonstrated catchability with gillnets), angling, minnow trapping and other gears will be performed as needed, such as if conditions prohibit safe or effective electrofishing. Additionally, standard water chemistry, channel morphology, and riparian habitat parameters will be recorded at each sample site. To enhance data quality and completeness and data entry efficiency, all collected data will be entered each day into an integrated database installed on a notebook computer.