In the western United States, the ability of non‐native lake trout (Salvelinus namaycush) to attain large sizes, > 18 kg under favorable conditions, fueled the popularity of lake trout fisheries. In the past, restrictive regulations were adopted to increase lake trout abundance and produce trophy specimens. More recently, lake trout have become increasingly problematic because they prey upon and potentially compete with native and sport fishes. We review the experiences of agencies in seven western states which are considering or implementing strategies to address lake trout impacts despite management difficulties due to mixed public perception about lake trout's complex interactions with native or introduced fauna. Special regulations protecting lake trout have often been liberalized or rescinded to encourage their harvest and reduce their negative effects. More intensive methods to control or reduce lake trout abundance include promoting or requiring lake trout harvest, commercial‐scale netting, disrupting spawning, and stocking sterile lake trout.

To quantify movement and abundance of lake trout Salvelinus namaycush in Lake Pend Oreille, Idaho, large trap nets were fished during two periods (

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To evaluate biological potential of a commercial fishery for an unexploited Lake Whitefish Coregonus clupeaformis population in Lake Pend Oreille, Idaho, we estimated population parameters related to production and yield. The length frequency based on trap‐netting in autumn 2005 was normal with a mean of 448 mm TL, whereas the length frequency based on gillnetting in spring 2006 was bimodal with a mean of 390 mm TL. Sex composition was skewed toward females (0.66) during autumn trap‐netting. Shape parameters β of weight–length models for females (β = 3.38) and males (β = 3.45) were similar to those of other unexploited populations. Instantaneous growth rates K for females (K = 0.144 per year) and males (K = 0.153 per year) were among the lowest for unexploited populations across the species’ range. Age at 50% maturity (females: 6.5 years; males: 6.0 years) and length at 50% maturity (females: 390 mm TL; males: 378 mm TL) were high for unexploited populations. The natural mortality rate M (0.149 per year, ages 11–36) was among the lowest observed for unexploited populations. Adult population density was lower than that of other populations based on total surface area (mean = 1.35 fish/ha; 95% confidence interval [CI] = 1.11–1.78 fish/ha) but was average based on lake area shallower than 70 m (4.07 fish/ha; 95% CI = 3.35–5.35 fish/ha). Population density of juveniles and adults averaged 84 fish/ha (95% CI = 52–143 fish/ha) over the entire surface area and 278 fish/ha (95% CI = 173–474 fish/ha) over depths shallower than 70 m. The difference between the low M of the unexploited population in Lake Pend Oreille (M = 0.149 per year; annual mortality rate A = 14%) and the high sustainable total mortality Z of exploited stocks in the Laurentian Great Lakes (Z = 1.204; A = 70%) suggests a large scope for sustainable fishing mortality F (1.055 per year; exploitation rate u = 61%) that is equivalent to a sustainable Lake Whitefish harvest of 55,000 individuals (50,000–60,000 individuals) and 49,000 kg (45,000–54,000 kg) from Lake Pend Oreille. Received February 24, 2014; accepted June 25, 2014

Common Carp Cyprinus carpio is a nonnative species that often has deleterious effects on aquatic systems. As such, there is interest in suppressing nonnative Common Carp populations in areas where humans have introduced them. The objectives of this study were to 1) provide insight on efficient techniques for capturing Common Carp, 2) describe their population demographics and dynamics, 3) evaluate whether temperature and water elevation were related to growth and recruitment, and 4) develop an age-structured population model for evaluating different management scenarios of Common Carp removal in Lake Spokane, Washington. Catch rates of Common Carp varied among sampling gears with slightly higher catch rates in monofilament (mean 6 SD; 15.5 6 9.8 fish/net night) vs. multifilament (12.7 6 7.3 fish/net night) gill nets. Catch rates of Common Carp with nighttime electrofishing (0.3 6 0.4 fish/min) were higher than daytime electrofishing (0.1 6 0.2 fish/min). Common Carp in Lake Spokane exhibited variable recruitment, rapid growth, large-length structure, high longevity (i.e., age 18 y), and low total annual mortality (17.0%). Air temperature was positively associated with annual growth increments (R 2 0.25). Neither air temperature nor water elevation was highly correlated (R 2 0.20) to recruitment of Common Carp. A Beverton-Holt yield-perrecruit model suggested that yield declined with increasing exploitation. Recruitment overfishing would occur at exploitation rates of 20-40% for all targeted minimum length categories (i.e., 150, 300, 450 mm) except 600 mm. Results from this study provide important information on the ecology of Common Carp that can be used to guide management efforts (e.g., suppression) in western systems.