Three Ghanaian reservoirs (Tono, Bontanga and Golinga) were compared through a food web modelling approach (Ecopath with Ecosim) to assess production characteristics and food web structures. The lakes differ in size and morphology, generating specific conditions for fish growth and production. While the two top fishery target species were Sarotherodon galilaeus (L.) and Oreochromis niloticus (L.) in

Within recent years, a slight but significant increase of European eel Anguilla anguilla (L.) recruitment has been documented, but it remains questionable whether or not the increased recruitment levels resulted in higher eel numbers at the regional scale. To detect the changes in yellow eel numbers, logbook data covering a 15-year time series of catch per unit effort (CPUE) data from the German Baltic

Climate change is predicted to cause increasingly frequent and intense storms. Northern Mongolia is already warming at a rate twice the global average, and thunderstorms, defined as intense, short, patchy rains associated with thunder, lightning and high precipitation rates, are becoming more frequent. Because Mongolia's fish populations are lightly exploited, Mongolia provides a model system in which

Barotrauma is a frequent event in fish captured from depth, and anglers often attempt to remedy this problem by venting fish. Barotrauma has been frequently assessed in fish during the warm water season, but no work has been done during winter ice angling, and the need and/or effectiveness of venting for ice-angled fish has not been quantified. To answer these questions, bluegill Lepomis macrochirus

Hatchery propagation techniques, such as pellet-rearing, can result in altered feeding behaviour. Walleye Sander vitreus (Mitchill) is a commonly propagated sportfish, yet little is known regarding its ability to switch to live prey post-stocking. The objectives were to evaluate temporal changes in diet composition and condition as well as evaluate the relationship between total length and presence

Hatch timing in autumn-spawning stream salmonids is poorly understood in the subarctic region because snow cover prevents direct sampling of cryptic early life stages. Otolith micro-increment analysis was used to infer hatch dates of white-spotted charr Salvelinus leucomaenis (Pallas) and masu salmon Oncorhynchus masou (Brevoort) in a mainstem-tributary network in northern Japan. Accuracy and precision

Fishers aim to optimise cost–benefit ratios of their behaviour when exploiting resources. Avoidance of interactions with marine predators (i.e. their feeding on catches in fishing gear, known as depredation) has recently become an important component of their decisions. How fishers minimise these interactions whilst maximising fishing success is poorly understood. This issue is addressed in a sub-Antarctic

Telemetry tags are increasingly used in management to monitor the migration timing of Atlantic salmon smolts (Salmo salar L.). It has been postulated that (1) effects from tagging and handling may alter migration behaviour, and (2) that the selection of fish during sampling is not representative of all migrating smolts, yielding bias in migration timing estimates. In the River Dale (Vestland, Norway)

Fishing with circle hooks along with prescribed hook-setting methods can reduce deep-hooking rates in some fisheries, but baited circle hooks have not been evaluated in stillwater trout fisheries. Deep-hooking rates and catch probabilities were compared for cutthroat trout Oncorhynchus clarkii​ (Richardson), rainbow trout Oncorhyncus mykiss (Walbaum), cutthroat × rainbow trout hybrids, and brook trout

Stocking and electrofishing occurrence and abundance data for northern pike Esox lucius L. in >3800 km of French rivers across 7 years were compared to assess the effect of recreational fisheries stocking programmes on wild pike populations. A positive relationship was found between the additive effect of stocking and the size of the stocked pike. However, the stocking programmes implemented in France

White (Carcharodon carcharias L.), bull (Carcharhinus leucas, Müller & Henle) and tiger (Galeocerdo cuvier, Péron & Lesueur) sharks are the primary species responsible for unprovoked shark bites. Historically, management practices were based on culling “target” shark species (i.e. white, bull and tiger sharks), which resulted in high levels of bycatch and mortality. Shark‐Management‐Alert‐in‐Real‐Time

Trap fisheries can provide catches of high quality, and unwanted bycatch can be released with high survival. Light attraction could be an effective way of increasing trap catches, but research results are largely lacking. Experiments to test the effect of LED lights in trap‐net fishing were conducted in two Finnish lakes where fishing targeted Eurasian perch Perca fluviatilis L. and roach Rutilus rutilus

Inland fisheries managers must account for multiple competing uses for aquatic resources; using methods such as ecosystem‐based management allows for different priorities for aquatic ecosystems to be accounted for. Declining abundance of kokanee salmon Oncorhynchus nerka (Walbaum) in Arrow Lakes Reservoir in the 1990s led to the use of large‐scale nutrient addition to improve productivity of kokanee

Downstream passage for juvenile Chinook salmon Oncorhynchus tshawytscha (Walbaum) and steelhead Oncorhynchus mykiss (Walbaum) through the fish weir at Foster Dam, Oregon, was evaluated to assess the weir's efficacy as a long‐term passage solution. Radio telemetry was used to estimate survival, passage and effectiveness for the fish weir, spillway and turbines. Survival of Chinook salmon through the

Migration behaviour, route selection and mortality of Atlantic salmon, Salmo salar L., smolts were studied at four different hydroelectric facilities in the River Mustionjoki, Finland, in May 2017. Radio‐tagged smolts were released upstream of the power stations and tracked by stationary antenna‐receiver systems and hand‐held receivers. Tracking revealed a general tendency of smolts to move downstream

Capturing the diversity of fishing fleets and identifying distinct subgroups is essential for effectively directing research and management efforts. In this study, the German Baltic gillnet fleet was split into distinguishable groups of vessels by applying a stepwise approach. Monthly landing profiles were classified using clustering techniques and arranged as annual landing sequences, as the basis

On the U.S. West Coast, reports of whales entangled in fishing gear increased dramatically in 2014. In this study, a time series of fishing activity maps was developed from 2009 to 2016 for the four fixed‐gear fisheries most commonly implicated in entanglements. Maps were generated using vessel monitoring system (VMS) data linked to port‐level landings databases, which were related to entangled whale

Allocating quotas among stakeholders requires an agreed‐upon formula. If the stock unit spans multiple management jurisdictions, the formula may require updated biomass estimates of the stock's spatial distribution with respect to those jurisdictions. Data for calculating stock biomass often come from fishery‐independent surveys. While stratified random sampling is a common design, strata boundaries

The accuracy of drift diving surveys of Atlantic salmon, Salmo salar L. and sea trout, Salmo trutta L., was evaluated by comparing the abundance and size distribution with catches in a fish trap over 6 years in the River Etneelva, western Norway. The population count from drift diving accounted for on average 96.3% of the salmon in the trap after accounting for the catches during fishing. Size structure

Atlantic salmon, Salmo salar L., stocks worldwide have dwindled, and stricter recreational fishing regulations have been implemented. This study estimates the recreational value of salmon fishing under different regulatory schemes and identifies factors explaining changes in net economic value of sport fishing. A Contingent Valuation mail survey in the Verdal River, Norway, asked anglers their willingness-to-pay

A nationwide recreational fishing survey in Sweden was used to estimate the benefits of recreational fishing in Sweden. The survey targeted the Swedish population and, consequently, the sample contained a large fraction of zero fishing days. To consider this, a zero-inflated Poisson model was used in the estimations. Swedes fished about 15.6 million days in 2013, of which two-thirds were spent on inland

Information about the population structure of Conger conger (L.) is scarce, being a limiting factor for fisheries assessment. To make available important baseline information and to test the hypothesis that the population in the mid‐North Atlantic (Azores region) represents a fishery management unit, fishery‐dependent and survey data relating to bathymetric distribution, length composition and movement

Despite their economic and ecological importance, migratory fishes of the Lower Mekong Basin (LMB) remain understudied, which hampers effective management to sustain valuable fisheries and address serious threats such as habitat degradation, development and overharvest. From a list of potential knowledge needs, a group of fisheries professionals most frequently identified six top priorities for managing

Terminal tackle regulations can be a valuable tool for fisheries management, especially in multispecies fisheries where bycatch and discards are common issues. In the Gulf of Maine, recreational anglers frequently discard critically depleted Atlantic cod Gadus morhua L. as bycatch when targeting the abundant haddock Melanogrammus aeglefinus (L.) stock. The present study investigated species catch composition

Fisheries are the most common ecosystem service that fish provide to human populations, yet recreational fisheries are often overlooked when evaluating such services. Here, the socioeconomic profiles of fishers, the composition of their catches and catch per unit effort (CPUE) are described, to estimate the economic value of the recreational fishery on a stretch of the Cuiabá River in the Brazilian

Understanding the dynamic spatial distribution characteristics and evolving trends in recreational fisheries development is of great importance for formulating policy for responsibly managing recreational fisheries. However, regional economic differences among China's recreational fisheries have yet to be examined and quantified. In this study, a methodological approach applies a series of techniques

Fish stocking and regulation of fishing activities are widely implemented by freshwater fisheries authorities who have to protect aquatic communities. The effects of fish management on fish communities have not received sufficient attention. As a result of two datasets, one from EU Water Framework Directive (WFD) monitoring surveys, and one from a French survey targeting angler's associations, this

Malaysian fisheries employ multiple measures to improve management; however, not all are well‐suited to the multispecies fisheries. As part of a pilot project, an individual quota system was introduced for the purse‐seine fishery off the East Coast of Peninsular Malaysia (ECPM), but no assessment of this particular measure nor the feasibly of its implementation has been confirmed. Therefore, this study

Historically, cisco Coregonus artedi Lesueur was the predominant prey fish and target of commercial fisheries throughout Lake Superior, but most spawning stocks collapsed by the mid‐1900s. Stocks partially recovered by the early 1990s, but contemporary abundance is considered to be below historical levels and driven by intermittent recruitment. Stochastic, age‐structured simulation models were used

A mixed‐stock fishery occurs when multiple populations of a fish species are exploited together in a common area where they aggregate outside the breeding season (e.g. for feeding or overwintering), and the aggregation is known as a mixture. Recreational fishing often exploits such mixtures, and estimating the proportional contributions of populations to fisheries promotes more sustainable resource

Although freshwater fish stocking is widely used by managers, quantitative assessments of stocking practices are lacking in many countries. The general objective of the present study was to determine the quantity and characteristics of fish stocking in metropolitan France. Using a survey-based approach, stocking practices for 2013 by recreational angling clubs in France were quantified, which represented

Quantifiable estimates of predator–prey interactions and relationships in aquatic habitats are difficult to obtain and rare, especially when individuals cannot be readily observed. To overcome this observational impediment, imaging sonar was used to assess the cooccurrence of predator‐size fish and juvenile salmonids, Oncorhynchus spp., at the entrance to a floating surface collector (FSC) in the forebay

The three‐spot cichlid Amphilophus trimaculatus (Günther) is an ornamental fish known to be invasive but has not been assessed for India. The present study confirmed this non‐native species’ identity using conventional and molecular methods, as well as its occurrence in the River Cauvery, the first for this species in a lotic environment outside its native range. Gut content analysis indicated a diet

Warming water temperatures, combined with increased mortality following catch and release, could have synergistic consequences if rivers remain open to catch and release at high water temperatures, and catchability of fish remains similar across water temperatures. Here archived data for Atlantic salmon, Salmo salar L., were used to (a) quantify the influence of water temperature on catchability and

A 40+ year programme to monitor brown trout, Salmo trutta L. (populations at 25 groundwater‐fed stream sites in southeast Minnesota, USA, was initiated to identify population trends, evaluate management actions and test ecological theories regulating populations. Significant increases between 1970 and 2018 were found for total biomass (an average of 5% annually) and abundance of juveniles (7%), all

Understanding salmonid discharge requirements can help inform management to conserve wild populations in a changing climate. This study developed Bayesian hierarchical mixed‐effects models relating 0+ Atlantic salmon (Salmo salar L.) and trout (Salmo trutta L.) densities to different aspects of river discharge. Associations between these densities and nine hydrological variables representing the magnitude

Effective protection of migratory fish requires long‐term conservation encompassing active restoration and management measures with follow‐up studies. The main findings of long‐term (1995–2019) monitoring of anadromous and potamodromous brown trout Salmo trutta in the River Bidasoa are presented. The main aims were evaluating trout number and median migration date changes, and assessing the effects

Recreational fishing can result in deep hooking (e.g. in the gullet) of fish that are intended to be released, leading to the development of various tools intended to assist with hook removal. So‐called “hook disgorgers” are typically marketed as being a mechanism to retrieve the hook while doing so in a way that reduces harm to the fish, despite there being many studies that demonstrate that it is

Double‐crested cormorant Phalacrocorox auritus Lesson (cormorant) populations have increased throughout the Great Lakes region of North America causing concern related to the impact of cormorant predation on fish communities. A recent decline in yellow perch Perca flavescens (Mitchill) abundance within the Lake Winnebago System, Wisconsin, USA, prompted an assessment of cormorant diets to evaluate

Biological invasions are a major driver of global environmental change as invasive non‐native species can exert severe environmental impacts on invaded ecosystems. Estuaries are especially vulnerable to biological invasions, which in highly urbanised areas are further facilitated by introduction pathways linked to commercial activities. This study provides a risk screening of non‐native invasive species

Culture‐based fisheries (CBF) are increasingly accepted as strategies for enhancing inland fisheries, especially in tropical Asia. In Sri Lanka, CBF development in irrigation reservoirs has gained momentum due to concerted efforts of government fisheries authorities for inland fisheries enhancement. In the present study, production trends of five irrigation reservoirs of Sri Lanka before and after

One of the actions that has been implemented to support the recovery of the panmictic population of European eel is stocking of waterbodies where natural recruitment is low or null. However, growth conditions of the stocked eels can vary greatly. This circumstance emphasises the importance to determine ideal habitat conditions to contribute to the success of stocking actions and, consequently, to increase

Hydropower development can result in both environmental and social change. Modification of riparian environments and the creation of storage reservoirs can alter fish assemblages, change access arrangements and create new opportunities within and outside fishing. These opportunities may be perceived differently by different stakeholders, leading to changes in the fishery and, ultimately, with implications

This study evaluated the status of native and stocked fish species in 13 prairie lakes in central Canada over eight years (2007–14) using three metrics: resource‐use (benthic versus pelagic carbon via stable isotopes); body condition (relative weight index Wr); and parasite load (cestode gut enumerations). Analyses included game and non‐game fishes, like naturally occurring northern pike, Esox lucius

Mark‐release‐recapture trials were conducted to determine the exploitation rate of glass eel Anguilla anguilla (L.) by handheld dip nets in the Severn Estuary in the spring of 2020. The glass eel were marked with Rhodamine B at a concentration of 0.1 g/L, 200 glass eel/L for 4.5 hr and then placed in fresh water for 36–48 hr to monitor mortality. In trial 1, 891 ± 100 of the 20,455 glass eel were recaptured

River‐reservoir interfaces have been described as aquatic ecotones and contain strong environmental gradients of depth, turbidity and trophic resource abundance. These transitional habitats have traditionally been excluded by riverine and reservoir management schemes despite their prevalence in modern riverscapes. By systematically sampling shoreline habitats along a river‐reservoir interface gradient

Tournament fishing has risen in popularity over the last half a century. As such, social and financial incentives combined with technological advancements are expected to drive changes in angler's capacity to exploit tournament‐eligible fish stocks, as has been observed in commercial fisheries. The aim of this study was to quantify temporal trends in angler efficiency and their ability to exploit a

European eel, Anguilla anguilla (L.), migrating to sea encounter many man‐made structures that can hamper and delay migration or induce mortality. Three pumping stations in Friesland, the Netherlands, were covered with acoustic receivers. Ninety‐three silver eels tagged with acoustic transmitters were released in the polders upstream of the stations and 89% were detected passing a pumping station.

Risk screening tools play a crucial role in identifying potential high‐risk non‐native (NN) fish species. In this study, potentially invasive NN fish species in the Anzali Wetland Complex (AWC), which is located on the south coast of the Caspian Sea (Iran), were identified using the Aquatic Species Invasiveness Screening Kit (AS‐ISK). Twenty‐nine freshwater fish species were screened of which 13 exist

Fisheries‐independent survey data are vital to stock assessment and management because they provide reliable information on stock status. Although survey data have been increasingly recognised for their contributions to fisheries management, they have often not been adequately used to provide quantitative management recommendations for China's fisheries that are subject to limited data. In the present

Accurate and consistent age readings are cornerstones of age‐based assessment and management of exploited fish stocks. Otoliths are the preferred structure for age determination, often performed by counting the number of completed 001 zones. Uncertainty regarding the identification of the first translucent zone and the timing of translucent zone formation can cause skewed age determination even in

Estimation of silver eel production, Anguilla anguilla L., is fundamental for the management of eel stocks. In the hydropower‐regulated rivers Shannon and Erne, Ireland, production is calculated using catch data from a conservation trap and transport programme. However, in both rivers gaps in silver eel catch datasets tend to occur, which can lead to biases in production estimates. Generalised additive

Several large Irish lake fisheries comprise both pike (Esox Lucius) and brown trout (Salmo trutta). Due to predation on trout, pike stocks are actively managed in several locations with the objective of enhancing the trout fishery, which is a policy strongly supported by some trout anglers but intensely opposed by pike anglers. In the context of scientific support for management decisions concerning

Understanding fishing participation assists sustainable fisheries management. Relative to commercial fisheries, however, accurate quantitative data on recreational fishing is often more challenging to collect. The quality and robustness of recreational fishing surveys to assess fisher numbers may be improved with cost‐effective remote sensing platforms, such as aerial drones. Here, the precision and

Foreign fishing tourism (FFT) is becoming increasingly popular in the developing world, where it often coexists alongside other important sectors involving domestic recreational anglers and dependant artisanal and subsistence fishing communities. Therefore, it is important that FFT operations use effective catch‐and‐release (C&R) angling to minimise negative impacts to locally important fishery species

Recruitment declines of walleye, Sander vitreus (Mitchill), observed in some northern Wisconsin lakes have resulted in management actions to evaluate and rehabilitate populations. An effective index for estimating relative abundance of yearling walleye is required. The objectives herein were : (a) to evaluate the relationship between yearling walleye electrofishing CPUE and density in northern Wisconsin

Trophic dynamics and conceptual niche spaces of top piscivores were assessed using stable isotope analysis following the introduction of hybrid striped bass Morone saxatilis (Walbaum) × Morone chrysops (Rafinesque) into an established reservoir fishery devoid of gizzard shad, Dorosoma cepedianum (Lasueur). Hybrid striped bass were initially stocked into Three Mile Lake, Iowa as an attempt to biologically

Results from an acoustic telemetry study revealed for the first time a northerly migration route for Atlantic salmon (Salmo salar L.) smolts leaving the east coast of Ireland. Atlantic salmon smolts were tagged in spring 2019 in the Castletown and Boyne rivers. Three tagged smolts registered on disparate deep‐water offshore marine receivers as they travelled northwards out of the Irish Sea through

Water competition in overallocated rivers is often extreme, and climate change exacerbates the challenge of balancing ecosystem and societal water needs. During a severe California drought in 2013–2014, storage in a strategic reservoir dropped to critically low levels, necessitating reduced downstream discharge during Chinook salmon, Oncorhynchus tshawytscha (Walbaum), incubation and rearing. In response

Catch rates were compared between gillnets with and without bait in the Greenland halibut Reinhardtius hippoglossoides (Walbaum) fishery off Baffin Island, Canada. Two different types of baiting techniques were compared: bait bags where squid were placed into 2‐mm mesh bags, and tied bait where squid were tied into meshes. Both types of baited gillnets significantly increased the capture of the target