Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Little attention has been given to optimizing statistical power for monitoring stream fish assemblages. We explored the relationship between temporal variability and statistical power using 34 metrics from fish community data collected annually at six sites over 10 years via electrofishing. Metric variability differed by the life stage

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The widely accepted belief that hatchery-origin salmon survive less well than natural-origin or wild salmon can be, at least in part, an artifact of the way hatchery salmon survival is estimated. Hatchery salmon are often marked several months before release, while natural salmon are marked during their seaward migration. Underestimated

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Urban stormwater is responsible for recurrent mortality events of coho salmon (Oncorhynchus kisutch) documented in the US Pacific Northwest. Currently, the toxic mode of action is unknown; however, mortality is often associated with large increases in hematocrit (Hct). We found that hemoconcentration and red cell swelling may offer

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Stream habitat changes affecting primary consumers often indirectly impact secondary consumers such as fishes. Blooms of the benthic algae Didymosphenia geminata (Didymo) are known to affect stream macroinvertebrates, but the potential indirect trophic impacts on fish consumers are poorly understood. In streams of the Kootenai River

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Resource subsidies exert critical influences on recipient habitats with relatively higher perimeter-to-area ratios, such as headwaters in watersheds. However, little is known about how those subsidies contribute to the energy sources in recipient habitats where the perimeter-to-area ratio is low, such as large stream channels. Here

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. We tested whether Δ14C values of eye lens protein (crystallin) formed in early life could be utilized to validate marine bony fish age estimates via the bomb radiocarbon chronometer. The slope of the relationship between red snapper (Lutjanus campechanus; n = 8; 0 to 27 years old), otolith and eye lens core Δ14C values was not significantly

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Many fisheries and marine science organizations are working to determine how to meet their missions in the midst of the COVID-19 outbreak. As such, it seems prudent to exchange ideas, share knowledge, and initiate a discussion among us. As the scientific leadership team for NOAA Fisheries, we wanted to offer some perspectives. Others

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Pop-up satellite archival tags (PSATs) have been used to demonstrate habitat utilization and large-scale migrations of aquatic species and are a critical tool to manage highly migratory fish populations. Use of PSATs has increased in recent years; however, few studies have investigated the physiological and behavioral effects of carrying

Canadian Journal of Fisheries and Aquatic Sciences, Volume 77, Issue 12, Page iii-iv, December 2020.

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Intra-annual reproductive investments may not be predictive of male reproductive success because of the effects of intra- and intersexual interactions on sperm depletion. For long-lived iteroparous fish species such as lake sturgeon (Acipenser fulvescens), reproductive effort may affect lifetime reproductive success. Radio frequency

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Alternative reproductive tactics are widespread in fishes. In Pacific salmon, males either become a competitive hooknose, or a sneaker jack, which is undesirable in aquaculture when overabundant. Juveniles often experience accelerated growth prior to becoming jacks, potentially caused by increased competitiveness. We tested the behaviour

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The southern king crab (Lithodes santolla) supports one of the most important fisheries in southern South America. Lecithotrophic larvae hatch over an extended period, in which brooding females can be fished, but must be discarded due to regulations. Larval mortality by female fishing was evaluated. Samples of newly hatched zoeae I

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Information on biological status is essential for designing, implementing, and evaluating management strategies and recovery plans for threatened or exploited species. However, the data required to quantify status are often limited, and it is important to understand how assessments of status may be biased by assumptions in data analysis

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Management of Atlantic cod (Gadus morhua) off southern Newfoundland (Northwest Atlantic Fisheries Organization (NAFO) Subdivision 3Ps) entails allocated quotas and restrictions on fishing during late winter and springtime to protect presumed spawning aggregations. We present data collected from research trawls and handlines (1995–2014)

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Fraser River Pacific salmon have declined in recent decades, possibly from parasitism by sea lice (Caligus clemensi and Lepeophtheirus salmonis). We describe the abundance of both louse species infesting co-migrating juvenile pink (Oncorhynchus gorbuscha), chum (Oncorhynchus keta), and sockeye (Oncorhynchus nerka) salmon over 5 years

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Although telemetry is commonly used to study fishes, researchers rarely design experiments that facilitate in situ quantification of tagging-related impacts to survival. We experimentally applied high (mean burden = 9.6%) and low (2.6%) acoustic tag burdens and gill clip biopsies to migrating juvenile sockeye salmon (Oncorhynchus nerka)

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Most previous systems for quantifying ventilatory flow in fish involve prior anesthesia and difficult surgery to sew or glue membranes to the animal, which are undoubtedly stressful. By modification of the original “van Dam box” design and incorporation of an electromagnetic blood flow probe, we have developed a less invasive system

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Sea lamprey (Petromyzon marinus) are invasive in the Laurentian Great Lakes and parasitically feed on valued fishes. Migration barriers and selective pesticides are used to control sea lamprey, but there is a desire to develop additional control tools such as traps with nonphysical deterrents. Sound has been used as a deterrent for

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The expression of anadromy in partially migratory salmonid populations is influenced by sex-specific interactions among an individual’s genotype, condition, and environment, but genotype–phenotype relationships prior to the expression of migratory type are poorly understood. We examined whether juvenile growth and condition differed

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Declining primary production has been proposed as an explanation for the declines in coho (Oncorhynchus kisutch) and Chinook (Oncorhynchus tshawytscha) salmon in the Salish Sea since the 1970s. Marine sediments maintain a continuous record of conditions in the overlying water. We used stable isotopes of organic carbon and nitrogen

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Strain performance evaluations are vital for developing successful fishery management and restoration strategies. Here, we utilized genotypes from 36 microsatellites to investigate hatchery strain contribution to collections of naturally produced lake trout (Salvelinus namaycush) sampled across Lake Michigan. Strain composition varied

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Understanding detection range is a key factor for the use of acoustic telemetry in fisheries research. Lakes have strong seasonal changes in thermal stratification, as well as short-term changes due to internal seiches. These thermal gradients in lakes imply strong sound-speed gradients that can refract and diverge acoustic signals

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Moving toward ecosystem-based fisheries management requires integration of biotic and abiotic factors into our understanding of population dynamics. Using blue crab (Callinectes sapidus) in the Chesapeake Bay as a model system, we applied Gaussian Graphical Models (GGMs) to understand the influence of climatic, water quality, and biotic

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. In recent decades, there has been a decline in the marine growth of Atlantic salmon (Salmo salar) over large parts of the distribution range. One hypothesis for this reduced growth is increased interspecific competition with other planktivorous pelagic fish in the ocean. Here, interactions between salmon postsmolts and other pelagic

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Worldwide declines in salmonid populations have generated major interest in conservation and restoration of wild populations and riverine habitats. Species reintroductions to previous habitats raise questions about their potential impact on these systems. In River Klarälven, landlocked Atlantic salmon (Salmo salar) have been extinct

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The number of effective breeders (Nb) has been touted as a means to monitor freshwater fishes, but the realized application of Nb has been limited. Using genetic monitoring data for two Arctic grayling (Thymallus arcticus) populations of conservation concern, we describe temporal trends in genetic variation and Nb, determine how sampling

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. We project how human population change (2018 to 2046) and aquatic invasive species (AIS) establishment events of bigheaded carps (Hypophthalmichthys spp.) and grass carp (Ctenopharyngodon idella) might combine to affect future Canadian recreational fishing activity for the Laurentian Great Lakes. Human population change is expected

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Fires are a natural phenomenon in the boreal forest, but their frequency is expected to increase over the coming century. Fires may affect water quality and invertebrates in lakes, but there have been few studies in the northern boreal forest to describe these impacts. We collected data on water quality, macrophytes, and invertebrates

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Fish recruitment is complex and difficult to predict. Data-driven approaches show promise for predicting recruitment and understanding its drivers. We used a random forest model to infer relationships between year-class strength and 17 variables describing potential recruitment drivers across 30+ years of walleye (Sander vitreus) data

Canadian Journal of Fisheries and Aquatic Sciences, Volume 78, Issue 2, Page 173-183, February 2021. A fundamental assumption of biotelemetry studies is that there are no adverse consequences from the surgical implantation or presence of the acoustic transmitter. In fisheries, most studies have evaluated this assumption over only short time periods (<2 years) in a laboratory setting. Here we compared

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. We develop a mechanistically motivated von Bertalanffy growth model to estimate growth rate and its predictors from spatial–temporal data and compare this model’s performance with a suite of commonly used mixed-effects growth models. We test these models with simulated data and then apply them to test whether concerns that high density

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Migrating adult Pacific salmon (Oncorhynchus spp.) are sensitive to warm water (>18 °C), with a range of consequences from decreased spawning success to early mortality. We examined the proportion of Yukon River Chinook salmon (O. tshawytscha) exhibiting evidence of heat stress to assess the potential that high temperatures contribute

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Climate change is altering hydrologic regimes, with implications for lake water levels. While lakes within lake districts experience the same climate, lakes may exhibit differential climate vulnerability regarding water level response to drought. We took advantage of a recent drought (∼2005–2010) and estimated changes in lake area

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. We evaluated the crustacean zooplankton size spectrum as an indicator of lake characteristics and ecosystem change. First, we used time series from seven Canadian Shield lakes to identify the factors associated with among-lake and among-year variability in the spectrum slope (relative abundance of small and large zooplankton) and centered

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Age composition is defined as the proportion of a fish population belonging to each age class and is an informative input to stock assessment models. Variations in somatic growth rates may lead to larger errors in age composition estimates. To reduce this source of error, we compared the performance of four methods for estimating age

Canadian Journal of Fisheries and Aquatic Sciences, Volume 78, Issue 2, Page 165-172, February 2021. Various abiotic and biotic factors affect fish and their habitats at macroscales. For example, changes in global temperatures will likely alter demographic rates, including growth. However, to date, there is no statistical framework for assessing the ability to detect macroscale effects on fish growth

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The River Continuum Concept (RCC) is a milestone in stream ecology because of its comprehensive evaluation of the structure and function of lotic ecosystems. Linking stream physical and geomorphological attributes with patterns in biodiversity, functional traits, and metabolism dynamics, this theory describes downstream gradients in

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Numerous laboratory and field studies have found that female Pacific salmon have higher mortality than males during their once-in-a-lifetime upriver spawning migration. However, the proximate cause(s) of this increased mortality are poorly understood. This study exposed sockeye salmon (Oncorhynchus nerka) to a mild capture and tagging

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Many animals undertaking long-distance migrations use Earth’s magnetic field as a “map” to assess their position for orientation. This phenomenon been particularly well-studied in salmonids using “magnetic displacement” experiments, in which animals are presented with magnetic field conditions that are characteristic of other geographic

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Introduced Pacific salmon (Oncorhynchus spp.) deliver novel, pulsed resource subsidies to Great Lakes streams. We explored interactions between native brook trout (Salvelinus fontinalis) and non-native brown trout (Salmo trutta) in the context of this resource pulse. Diets surveyed before and during salmon spawning showed that, regardless

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Behaviour that is adaptive in captivity may be maladaptive in the wild and compromise postrelease survival of hatchery fish. The understanding of behavioural variation displayed immediately after release could help to improve hatchery protocols and development of behavioural tests for assessing the fitness of fish reared for releases

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. In streams where water availability is limited, conservative flow ranges are often adopted by water managers to ensure that streamflow is available to meet the ecological requirements of aquatic organisms. However, a variety of natural and anthropogenic disturbances can influence stream channel morphology and in-stream wood characteristics

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. During stock assessment, fishery-dependent observations are often used to develop indices of abundance or biomass from catch per unit of effort (CPUE) and contribute catch at size or age information. However, fisher behavior, rather than scientific sampling protocols, determines the spatial and temporal locations of fishery-dependent

Canadian Journal of Fisheries and Aquatic Sciences, Volume 77, Issue 10, Page 1612-1624, October 2020. The Arctic nearshore surrounding Point Barrow, Alaska, is a dynamic system with complex oceanographic and meteorological processes that drive community composition to change rapidly in space and time. Nearshore fish and zooplankton communities were sampled in the summers of 2013–2015. Spatial, temporal

Canadian Journal of Fisheries and Aquatic Sciences, Volume 78, Issue 2, Page 184-192, February 2021. Certain spawning areas of the critically endangered Lake Saimaa landlocked Atlantic salmon (Salmo salar m. sebago) have been recently restored by excavator- and helicopter-scattered gravel, but the success of applied methodologies has remained open. Here, we monitored the spawning-related movements

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. The relationship between littoral macroinvertebrate communities and environmental gradients in Arctic lakes is poorly understood, making it difficult to predict whether these important components of lake ecosystems will be affected by emerging stressors such as permafrost thaw and road development. To better understand how littoral

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Despite the preponderance of exorheic lakes in rivers home to anadromous salmonids, little research has focused on how salmon, trout, and char use lakes as part of their anadromous life histories. The literature on this subject has so far revealed that some parr move into lakes to feed and grow before smoltification but that smolts

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Exotic prey fishes that have high thiaminase levels are associated with a thiamine deficiency and reduced fitness in many salmonids. If sensitivity to low thiamine availability differs among the three Atlantic salmon (Salmo salar) populations targeted for reintroduction into Lake Ontario, this could substantially influence their performance

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Eulachon (Thaleichthys pacificus), a culturally and ecologically important anadromous smelt (Family Osmeridae), ranges from Northern California to the southeast Bering Sea. In recent decades, some populations have experienced declines. Here we use a contig-level genome assembly combined with previously published restriction site-associated

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Median timing of reproduction in salmonid populations is generally consistent among years, reflecting long-term patterns of natural selection from characteristics of the local environment. However, altered selection from factors related to climate change or human intervention might shift timing over generations, with implications for

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. In fishes, physiological and behavioural traits can correlate with vulnerability to capture with fishing gears, highlighting the capacity of fisheries selection to drive phenotypic change in exploited populations. There remains a paucity of information regarding how different fishing gears may select on phenotypic traits and how relationships

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Restoration practices aimed at fish habitat enhancement often include installation of instream structures. However, mixed outcomes have been reported regarding structure effectiveness, while mechanisms underlying success remain unclear. The interactions between fish and flow conditions generated by instream structures and their subsequent

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print. Passage of hydropower plants by upstream-migrating salmonid spawners is associated with reduced migration success, and the need for knowledge of fish behavior downstream of dams is widely recognized. In this study, we examined fishway passage of landlocked Atlantic salmon (Salmo salar) in River Klarälven, Sweden, and brown trout (Salmo

Canadian Journal of Fisheries and Aquatic Sciences, e-First Articles. Two primary goals in fisheries research are to (i) understand how habitat and environmental conditions influence the distribution of fishes across the landscape and (ii) make predictions about how fish communities will respond to environmental and anthropogenic change. In inland, freshwater ecosystems, quantitative approaches traditionally

Canadian Journal of Fisheries and Aquatic Sciences, e-First Articles. Analysis of growth increments in the hard parts of animals (e.g., fish otoliths) can be used to assess how organisms respond to variability in environmental conditions. In this study, mixed-effects models were applied to otolith data simulated for two hypothetical fish populations with assumed biological parameters and known growth

Canadian Journal of Fisheries and Aquatic Sciences, e-First Articles. The ability of passive integrated transponder (PIT) tag data to improve demographic parameter estimates has led to the rapid advancement of PIT tag systems. However, ghost tags create uncertainty about detected tag status (i.e., live fish or ghost tag) when using mobile interrogation systems. We developed a method to differentiate

Canadian Journal of Fisheries and Aquatic Sciences, e-First Articles. Owing to declines in salmonid populations, in-stream restoration structures have been used for over 80 years to increase abundance of fish. However, the relative effectiveness of these structures remains unclear for some species or regions, partly due to contrasting conclusions from two previous meta-analyses. To update and reconcile