Climate change is altering the spatial and temporal patterns of temperature and discharge in rivers, which is expected to have implications for the life stages of anadromous fish using those rivers. We developed an individual‐based model to track American Shad Alosa sapidissima offspring within a coarse template of spatially and temporally variable habitat conditions defined by a combination of temperature

Accurate estimates of age composition are essential for fisheries management, but evaluation of protocols to estimate age data are rarely conducted. Herein, known‐age Pacific salmon from six hatchery stocks were used to examine accuracy of multiple scale aging protocols and to assess how errors in age assignment may affect age composition estimated from scale data. Accuracy reached 1.0 for one stock

We evaluated Silver Carp catch per unit of effort (CPUE fish/6,000 m3) using an electrified butterfly trawl (paupier) among various temporal (time of day, season) and spatial (location, habitat [shoreline and open water], water depth) factors likely to be influential in large lentic habitats. The paupier sampled the upper water column (1.5 m) in three locations (i.e., two Kentucky Lake embayments and

The detection of fish by using environmental DNA (eDNA) analysis has been shown to be more cost‐effective than traditional sampling methods are in certain situations, but this method has not been assessed under extreme winter conditions. We conducted a multiyear pilot study to test the effectiveness of eDNA for detecting fish under ice. In the spring of 2016, 2017, and 2018, we sampled for juvenile

Ceratonova shasta is an endemic myxozoan parasite that impacts salmonid populations in the Klamath River (USA). High densities of C. shasta actinospores negatively affect the survival of migrating juvenile salmonids. Each year, five million fall‐run Chinook Salmon smolts (Oncorhynchus tshawytscha) are released from a hatchery located below Iron Gate Dam, and travel through an infectious zone where

Biological data collected in commercial port sampling programs are a critical component of the assessment and management of Gulf Menhaden Brevoortia patronus and Atlantic Menhaden Brevoortia tyrannus. The menhaden port sampling program represents one of the longest, continuous commercial sampling efforts in the U.S; however, this sampling program has not been evaluated recently to determine if the

The feasibility of using sonar in Alaska's lower Kvichak River, a region with a 3.8 m tidal flux, to assess the abundance of adult Sockeye Salmon Oncorhynchus nerka was evaluated as a replacement for an in‐river gill‐net test fishery. Test fish indices are one tool that is used to manage commercial and subsistence fisheries in Bristol Bay. On this river, an observation tower project near the clear

Comparisons of local population growth rates to species averages are valuable for natural resource managers because growth rates provide an integrated evaluation of abiotic and biotic factors that regulate growth in a fishery and may inform management decisions. Thus, species‐specific standard growth models pave the way for fisheries scientists to efficiently compare, evaluate the status, and determine

Conservation and restoration of gar (Lepisosteidae) populations in North America are increasingly of interest to fisheries managers. Alligator Gar Atractosteus spatula are being stocked as age‐0 fish in efforts to re‐establish extirpated populations. However, gars are known to be highly cannibalistic in hatcheries, suggesting that age‐0 Alligator Gar introduced into natural habitats may face predation

One frequently desired outcome of Lake Sturgeon Acipenser fulvescens rehabilitation is to create a recreational fishery for the species. However, few waterbodies offer a recreational fishery where anglers can catch Lake Sturgeon regularly. Lake St. Clair and the St. Clair River (hereafter, “St. Clair system”) contain large, stable populations of Lake Sturgeon, and a recreational fishery allowing harvest

In Alabama, Alligator Gar Atractosteus spatula populations have experienced a decline in abundance and due to their limited distribution are classified as a nongame species of moderate conservation concern. Conservation management plans have included creel limits and stocking to augment a diminished population within the lower Alabama River. Our objective was to evaluate gill‐net efficacy on catch

Pass‐through PIT antennae are often used in river and stream habitats to monitor the movement of aquatic species. Where these habitats are prone to high flows that contain suspended debris, traditional pass‐through antennae designs are particularly vulnerable to damage, which can be time consuming and expensive to repair and lead to extended gaps in data collection. We designed and tested a novel pass‐through

Simultaneous management actions often are used to improve the status of imperiled species yet the effects of these actions can be difficult to determine. The endangered Rio Grande Silvery Minnow is a short‐lived fish with a dispersive life history and thus requires‐ but does not occupy‐ unfragmented habitat for recruitment and survival. We used Rio Grande Silvery Minnow as a model system for an individual‐based

Continued management interest in using White Sucker Catostomus commersonii population manipulations to improve the growth of Northern Pike Esox lucius and potentially competing panfish species provided an opportunity to evaluate White Sucker removal and supplementation in Michigan lakes. Overabundant White Suckers from one lake were transferred into two lakes where higher populations were desired,

The success of fish stocking programs is dependent on poststocking survival. However, survival can be influenced by size‐selective mortality, where larger individuals are expected to be less vulnerable to predation. Walleye Sander vitreus is a commonly stocked sport fish, but little is known regarding the role of size‐selective predation on age‐0 Walleye (90–290 mm TL) that are stocked in the presence

Floodplains are an important part of large‐river ecosystems; the frequency, timing, duration, and spatial extent of inundation drive habitat quality and determine the suitability of these habitats for both aquatic and terrestrial organisms. Managers have traditionally had very limited information with which to evaluate and quantify the dynamics of large‐river floodplains. Alligator Gar Atractosteus

The Lake Sturgeon Acipenser fulvescens is native to three major watersheds in the USA: the Great Lakes, Hudson Bay, and Mississippi River drainages. However, they have declined across much of their range due to overfishing, pollution, and major river alterations. After their near extirpation in Missouri, the Missouri Department of Conservation initiated a reintroduction program to restore the Lake

In temperate waters, growth and mortality of bony fishes are frequently estimated from age information derived from the examination of annular rings on hard structures (e.g., otoliths). However, determining ages from hard structures can be time consuming, often requires sacrificing fish, and has associated costs for supplies and personnel time in processing or reading structures. Subsampling based

Sustainable fisheries management is built on effective management strategies and informative data that are usually well defined for data‐rich fisheries. However, their counterparts in data‐limited fisheries remain inadequately evaluated due to insufficient data for stock assessments. This raises two questions: (1) can data‐limited management strategies achieve sustainable fisheries and (2) are certain

Programs to control predatory fishes have successfully increased the survival of imperiled prey fishes in some cases, but efficacy depends on the population dynamics and ecological interactions between the predators, prey, and the rest of the community. In California's Sacramento–San Joaquin Delta, extremely low survival of downstream‐migrating juvenile salmonids has been ascribed in part to predation

Advances in underwater camera technology provide an affordable means to quantify the environmental conditions under which fish spawn. This information is important for investigating spawning ecology, managing habitat, or providing information for captive breeding programs. We deployed 12 modified security cameras underwater to identify environmental conditions related to the spawning behavior of the

Recreational fisheries are often managed to provide satisfying fishing experiences for anglers while conserving wild fish stocks. However, managing recreational fisheries is difficult because fish populations are often infrequently monitored and fishing effort is uncontrolled; moreover, a satisfying fishery may draw many anglers, which may lead to enhanced risk of overfishing. Furthermore, external

Stocking Walleye Sander vitreus is a common management tool to augment populations where natural reproduction is limited. Some hatcheries have progressively raised larger fingerling Walleye to improve poststocking survival; however, little is known about the poststocking survival and behavior of large fingerling Walleye. We sought to evaluate the poststocking daily apparent survival, depth use, dispersal

Stock enhancement programs often involve the introduction of hatchery‐reared fish into wild environments, with the goal of increasing the abundance of a particular stock. To measure the success of stocking efforts for depressed populations, hatchery‐reared individuals must be distinguishable from naturally spawned fish, potentially many years after release. Biological tags are attractive due to their

The use of hydroacoustic techniques is increasing as scientists search for less invasive ways to monitor fish populations, and using recreational side‐scan sonar (SSS) imagery for monitoring has become more common in aquatic resource management over the last 15 years due in part to its low cost and user‐friendly interface. The time‐consuming nature of manually counting fish targets has limited the

The management of fish populations often requires an understanding of how density‐dependent effects influence population dynamics. In systems where natural populations are supplemented with stocking, the question of “how much food is available” becomes increasingly important. One typical approach for assessing density‐dependent interactions is to identify disparities between fish consumption rates

Fisheries managers regularly use catch‐per‐effort (CPE) statistics and length‐frequency distributions from standard gill‐net surveys to inform future management activities. The data from these surveys is implicitly tied to the net's selectivity, and caution should be used when not accounting for selectivity. We combined indirect and direct methods for estimating the parameters of absolute selectivity

We tested the ability of venting and descender (recompression) devices to increase the relative survival of released Black Sea Bass Centropristis striata, a physoclistous reef species with high discard rates in hook‐and‐line fisheries that operate in the U.S. Atlantic Ocean and Gulf of Mexico. We caught fish via hook and line from waters that were 38 m deep, a depth where Black Sea Bass often exhibit

Introduced Utah Chub Gila atraria were first sampled in Henrys Lake, Idaho, in 1993, and their presence in the system is a concern given possible interactions with sport fishes. Our objective was to describe the population dynamics of Utah Chub in Henrys Lake. A total of 362 Utah Chub was sampled via gill nets, with an average catch rate of 20.5 fish/net‐night (SE = 6.0) during May 2016. Average TL

The routine assessment and monitoring of aquatic habitat characteristics, such as submerged aquatic vegetation (SAV), is a fundamental tool in fisheries management. The relative low cost and availability of recreation‐grade side‐scan sonar (SSS) systems has made capturing high‐resolution (<10 cm) underwater imagery a practical and viable tool for improving these assessments. Using Humminbird SSS and

The Snake River, Idaho, between Swan Falls and Brownlee dams supports a popular fishery for Smallmouth Bass Micropterus dolomieu. Recently, anglers have expressed concern about harvest of Smallmouth Bass associated with seasonal congregations in and near the lower reaches of several major tributaries. Little is known about Smallmouth Bass movement in the system, and a better understanding of movement

Measuring the burst speeds of fish has long been problematic due to the lack of in situ measurements. Using boat‐mounted cameras, we recorded video of invasive Silver Carp Hypophthalmichthys molitrix in the field as they were leaping from the water and measured their leap height, horizontal distance, and angle of escape and estimated their escape velocity. Leap characteristics, fish morphometrics,

In freshwater fishes, the nitrogen and carbon stable isotopes ratios in tissues commonly reflect the environment in which a fish is feeding, assimilated through its diet. For many species, small‐bodied or younger individuals generally feed lower in the food chain, while large‐bodied mature individuals feed at higher trophic levels. This is reflected in the stable isotope (SI) ratios within fish tissue

Management agencies are often charged with providing fisheries that lead to angler participation. Catch rate is one of the primary drivers of angler participation but can be influenced by a suite of factors, including population structure (e.g., density and size structure). The complexity of understanding how population structure influences angler catch rate is typified in kokanee Oncorhynchus nerka

A recent increase in the abundance of snook species (Centropomus spp.) in Texas has been generally associated with a broad‐scale warming trend of Texas’ inshore waters, closure of the commercial fishery in 1987, and fairly conservative restrictions on recreational catch implemented at the same time. Despite this observed increase in abundance, little is known about the snook species complex in Texas

Adult Pacific salmon Oncorhynchus spp. undertake energetically demanding migrations where they must have adequate energy reserves to survive to reach spawning locations and reproduce. Lethal proximate analysis provides insight into available energy stores (e.g., lipids), but the ability to monitor energetic status nonlethally may be useful for managers. Nonlethal monitoring may be more cost effective

Conserving Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri by suppressing invasive Lake Trout Salvelinus namaycush in Yellowstone Lake is a high priority for Yellowstone National Park resource managers. Here, we tested whether targeting telemetered Lake Trout could increase the efficacy of Lake Trout suppression by gill netting. Mobile acoustic tracking surveys were performed to identify

The natural mortality rates and fecundity of Red Snapper Lutjanus campechanus vary substantially by age, so the age composition of catch is an important consideration when quantifying the relative effects of catch on the Red Snapper population across different fisheries. For example, the shrimp fishery catches many (but younger) Red Snapper, whereas directed commercial and recreational fisheries catch

Steelhead (the anadromous form of Rainbow Trout Oncorhynchus mykiss) exhibit a complex life history that is described by variable freshwater and ocean residency and maturation schedules. This diversity confers resilience but complicates their monitoring and management. The Situk River in Southeast Alaska has the longest running set of biological data and scale samples for steelhead in the state, and

Supplementing fish populations at the egg stage is a low‐cost alternative to hatchery rearing that is presumed to improve adaptation to local natural conditions. The Shoshone‐Bannock Tribes began supplementing Chinook Salmon Onchorynchus tschwytscha in Panther Creek, Idaho, at the eyed egg stage in 2014. The Chinook Salmon eggs were artificially fertilized and reared to eye‐up in the hatchery and then

Translocations, defined herein as the human‐assisted movement of individuals from a source population to other waters within their historical range, are prevalent in recovery plans for endangered fishes. Many translocations fail to establish new populations, however, and outcomes are often poorly documented. Endangered Humpback Chub Gila cypha persist as a self‐sustaining population in Grand Canyon

Natural and anthropogenic sources of sedimentation have the potential to degrade spawning habitat and negatively affect incubating fish embryos. Walleye Sander vitreus are lithophilic broadcast spawners that use specific spawning habitats that are vulnerable to degradation caused by deposition of suspended sediments. We measured the effect of different types of sediment cover on hatching success of

Evaluation and monitoring of stocking effectiveness is essential to make informed fisheries management decisions. Chemical marking, such as oxytetracycline (OTC), is often used for differentiating stocked from wild fish but has inherent error in mark longevity and otolith evaluation. Genetic analysis of recaptures provides a viable alternative. In this study, fingerlings (~50 mm TL) of F1 intergrade

We used sibship analysis to further our understanding of Alligator Gar Atractosteus spatula reproductive biology. Quantifying the relative contributions of spawners and spatial patterns of reproduction is important in making management decisions, especially with regard to long‐lived, large‐bodied fish like Alligator Gar, for which exploitation of large females may negatively impact recruitment. Using

Habitat segregation and hypothesized biotic interactions among coexisting gar species may confound attempts to describe the distributions of these species by using only macrohabitat availability in the presence of conspecifics. However, the strength of interactions among gar species and the spatial scale at which they occur are largely unknown. We used an existing data set to evaluate the co‐occurrence

Water temperature influences both morphological and physiological development in fishes. However, the effects of water temperature on the early development of Alligator Gar Atractosteus spatula and Spotted Gar Lepisosteus oculatus are not well understood. Both gar species were collected from natural environments and spawned in a hatchery setting. After spawning, fertilized embryos were collected and

Within a population, larger individuals tend to have higher fecundity and produce higher quality eggs. For this reason, larger, older females often disproportionately contribute to recruitment. However, increases in body size and age have also been shown to correlate with increased bioaccumulation of environmental contaminants, which negatively impact reproduction and larval survival. In this study

Considerable efforts have been undertaken to characterize population dynamics of the Alligator Gar Atractosteus spatula. Accomplishing this task required identification of suitable structures to estimate age. Buckmeier et al. (2012) validated sagittal otoliths to 31 years—the oldest fish in their study. However, they noted that interpreting annuli became increasingly difficult with age and cautioned

Boating is a major vector for aquatic invasive species that cause significant economic and ecological impacts, necessitating biofouling control that goes beyond simply maintaining boat operations. However, new regulations restricting the use of antifouling paints—a common control tactic along with hull cleaning—have not considered the consequences to invasive species management. As a result, there

Alligator Gar Atractosteus spatula are increasingly being stocked to restore populations, making the need to identify stocked individuals important for monitoring. Oxytetracycline (OTC) immersion allows for large numbers of fish to be marked simultaneously, thus eliminating the need to handle fish individually, but protocols for doing so have not been investigated fully for this species. In this study

The quagga mussel Dreissena bugensis is a harmful aquatic pest that invaded the southwestern USA in 2007. Challenges with managing this pest have been encountered because the invaded systems are primarily open‐water sources used for human consumption and/or are connected to freshwater habitats containing threatened and endangered species. Existing chemical and physical control methods are undesirable

The Alligator Gar Atractosteus spatula (AG) is a long‐lived fish of growing management and conservation interest. Situated on the border of Texas and Oklahoma, Lake Texoma supports one of the last robust AG populations in Oklahoma; however, a genetic evaluation of this population is lacking. We genotyped AG individuals with 17 microsatellite loci, 7 of which also cross‐amplified in three sympatric

Chemical controls ranging from natural products to synthesized chemicals are widely used in aquatic pest management activities. Chemicals can be used to lure organisms to traps or can cause direct mortality by altering the physiological function of an organism. Much of what is known about controlling pests with chemicals is from research done on terrestrial pesticides. This paper focuses on how chemicals

Aquatic invasive plants and animals are increasingly becoming a problem, causing severe economic and ecological damage to critical freshwater systems. The best strategy for controlling an invasive pest employs an integrated pest management (IPM) approach using a combination of biological, physical, chemical, and social/cultural control methods. Here, we examine the history and development of IPM and

Annual increment periodicity has been validated in sagittal otoliths of Alligator Gar Atractosteus spatula; however, discontinuities (often referred to as false annuli or checks) are common in early years, potentially affecting both accuracy and precision. We used up to four injections of oxytetracycline (OTC) to induce time stamps associated with annuli (opaque zones) in the otoliths of juvenile Alligator

Implementing integrated pest management (IPM) approaches to prevent invasion, contain and control established freshwater aquatic invasive animals (AIAs), and mitigate the impacts of those species has been limited, in part, because of policy‐related challenges. Scientific tools are being developed and tested that are designed to enhance IPM effectiveness and efficiency for managing AIAs. However, policy

The distribution and relative abundance of Westslope Cutthroat Trout Oncorhynchus clarkii lewisi (WCT) in relation to habitat characteristics remains unknown across large portions of its range. The goals of this research were to provide a foundational understanding of WCT distribution and relative abundance related to habitat characteristics in tributaries of the St. Maries River, Idaho—a highly altered

Bycatch is a major problem in most commercial fisheries around the world and is among the biggest challenges for fisheries managers tasked with conserving, protecting, and sustaining marine resources. Bycatch of protected species is particularly problematic because even small levels of bycatch mortality can hinder conservation efforts. The federally protected Atlantic Sturgeon Acipenser oxyrinchus

Passage of downstream‐migrating fishes through hydropower dams poses a management issue in rivers throughout the world. As such, regulations have been enacted at many locales to understand and limit fish losses by requiring dam passage survival estimation. However, limiting estimates of survival to the dam and immediate tailrace presents a challenge to researchers. In this study, two alternative release‐recapture

Previous work relating adult age data to historic hydrology indicated that strong year classes of Alligator Gar Atractosteus spatula were rare, tied to major flooding events, and linked to the inundation and connectivity of floodplain habitats. While spawning habitat suitability criteria have been correlated with successful recruitment in Texas Alligator Gar populations, direct evaluation of recruitment