Within the western Great Lakes (WGL) region of the USA (Michigan, Minnesota, and Wisconsin), the ecological impact that the North American beaver Castor canadensis (hereafter, "beaver") has on coldwater streams is generally considered to negatively affect salmonid populations where the two taxa interact. Beavers are common and widespread within the WGL region, while coldwater streams that support salmonid populations are scarcer landscape features; as such, all three states currently prioritize the habitat needs of salmonids in portions of each state by conducting beaver control in coldwater tributaries. In this paper, we review the history of beaver-salmonid interactions within the WGL region, describe how this relationship and management actions have evolved over the past century, and review all published studies from the region that have evaluated beaver-salmonid interactions. Our review suggests that beavers' impact varies spatially and temporally depending on a variety of local ecological characteristics (e.g., stream gradient and prevalence of groundwater inputs). We found that beaver activity is often deleterious to salmonids in low-gradient stream basins but is generally beneficial in highgradient basins and that ample groundwater inputs can offset the potential negative effects of beavers by stabilizing the hydrologic and thermal regimes within streams. However, there was an obvious lack of empirical data and/or experimental controls within the reviewed studies, which we suggest emphasizes the need for more data-driven beaver-salmonid research in the WGL region. Resource managers are routinely faced with an ecological dilemma between maintaining natural environmental processes within coldwater ecosystems and conducting beaver control for the benefit of salmonids; this dilemma is further complicated when the salmonids in question belong to nonnative species. We anticipate that future beaver-salmonid research will lead to a greater understanding of this ecologically complex relationship, allowing managers to be better informed of when and where beaver control is necessary to achieve the desired management objectives. found increased water temperatures downstream of dams, and Twork (1936) reported a decrease in temperature after dam removal; however, stream temperatures did not exceed the thermal limits for Brook Trout (20-24°C). 1208 JOHNSON-BICE ET AL. ate the three anonymous reviewers for comments that improved the manuscript.

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On June 20, 2021, the Northern Highland Fishery Research Area (NHFRA) celebrated its 75th anniversary of continuous fisheries population monitoring and compulsory angler creel census on five lakes in northern Wisconsin. In 1946, five lakes were designated as experimental fisheries research lakes and all anglers have been required to adhere to the compulsory creel census to record catch information. We review the history of the NHFRA, its role in evaluating experimental regulations, how data derived from the NHFRA were paramount in developing a critical Walleye Sander vitreus management plan for a joint tribal subsistence and recreational angling fishery, discuss the NHFRA as a training ground for early career fisheries professionals, and speculate on its future. By learning from the past and adapting to new challenges and emerging fisheries research needs, the NHFRA is poised to add to its 75‐year legacy of research and training to inform science‐based decision making and to prepare generations of new fisheries professionals. The 75‐year history of the NHFRA exemplifies the importance of adaptation, long‐term data, establishing sentinel lakes for observations of environmental change, field stations, and partnerships for successful fisheries management.

Angler trip success and catch rates are dependent upon a fishes’ vulnerability to angling. Angling vulnerability can be influenced by angler-specific attributes (i.e., bait choice, lure size, use of a guide), and individual fish traits (i.e., boldness, aggression, stress responsiveness, and memory retention). The mechanisms that function in a fishes’ angling vulnerability, and contribute to catch rate, are likely correlated with environmental factors however, the influence of environmental factors on angling vulnerability are not well understood. We used the long-term (1946 –present) compulsory creel dataset from Escanaba Lake, WI, USA to test for interactions between angling vulnerability (i.e., angler trip success and catch rates) and environmental factors to better understand these dynamics in recreational fisheries. Our objective was to test for the influence of angler associated variables and environmental factors on open water angler trip success (i.e., catch ≥ one fish) and catch rate of walleye Sander vitreus and muskellunge Esox masquinongy during 2003–2015 using a hurdle model approach. Fishing trip success and catch rates for both species were most strongly influenced by angler-related variables (i.e., guide status, bait type, the proportion of the fish population previously caught). Environmental factors associated with lower light intensity (i.e., diel period, mean daily solar radiation, solar-Julian day interaction) had a positive influence on walleye vulnerability. Lower air temperatures and lunar position (moon overhead or underfoot) and phase (gibbous’ and full moon) also had a positive effect on walleye angling. Muskellunge trip success and catch rate were positively influenced by light metrics (i.e., diel period and mean daily solar radiation) and increased with air temperature. Lunar variables (position and phase), as well as wind speed and direction also influenced muskellunge angling vulnerability. A better understanding of the influence of environmental factors on angling vulnerability is an important component of fisheries management as management goals focus on balancing fish populations and creating satisfactory catch rates to enhance the angling experience. Our results suggest that angler-specific variables, light, temperature, lunar, and weather conditions influenced species-specific angling vulnerability for walleye and muskellunge.

The Brook Trout Salvelinus fontinalis is a native salmonid that provides a valued and productive sport fishery in northeastern Minnesota. Revival of North American beaver Castor canadensis (hereafter, "beaver") populations since their near extermination and concern over their impacts on Brook Trout habitat prompted a reexamination of the complex ecological relationship where the two taxa interact. Suitable Brook Trout habitat is characterized by cold, spring-fed water with silt-free rocky substrate and abundant cover, all of which beaver may directly or indirectly affect. Data collection occurred on 79 stream sections (200 m each) and 21 beaver ponds spanning the North Shore of Lake Superior during the summer in 2017 and 2018. Habitat suitability index (HSI) models determined the average HSI and quantity of suitable Brook Trout habitat (m 2 /100 m 2 ) at stream and beaver pond sites, and a bioenergetics model calculated Brook Trout growth availability (m 2 /100 m 2 ) and mean growth (g/d) at stream sites. Classification regression trees identified significant thresholds at which beaver activity (e.g., number of dams upstream of sampled sites and beaver pond age) influenced the quantity or quality of Brook Trout habitat and growth. No significant variables were identified as affecting Brook Trout habitat or growth rates in stream sites. Alternatively, the quantity and quality of Brook Trout habitat in this region appeared to be influenced by microhabitat variables (depth, velocity, and temperature) that are eminent at individual stream sites. Brook Trout growth was strongly influenced by velocity (m/s) and mean prey concentration (mg dry mass/m 3 ). Results indicated that 12 of the 21 sampled beaver ponds contained suitable Brook Trout habitat, with dissolved oxygen (mg/L) identified as a threshold. This study recommends focusing on individual stream characteristics and beaver pond dissolved oxygen concentrations to achieve desired Brook Trout habitat and aid in the development of management strategies pertaining to these two taxa in Lake Superior's North Shore streams.