The notothenid Patagonotothen ramsayi is one of the most abundant fin fish species on the Patagonian Shelf and it is an important prey species and central to the trophic ecology of the shelf ecosystem of the region. 353 otoliths and the parasites analysed from 80 fishes collected in January 2010, and 2004 and 2006, respectively, from the Falkland Islands Shelf and in an area north of the Falkland Islands

Fish populations with spatial structure inherently violate the assumption of a single well-mixed stock, necessitating the use of spatially-structured population dynamics models. Accounting for spatial structure accurately and easily is a major goal for the next generation of stock assessment software development. Reference points (e.g., limit or target harvest rates and their associated biomass) are

Lumpfish (Cyclopterus lumpus) are the target of commercial fisheries in several countries. However, the collection of biological data for stock assessment purposes is both logistically difficult and expensive. The fishery takes place far from major population centres, over a wide geographical area, and, the roe is extracted at sea and the carcass is not landed in the majority of countries where lumpfish

Fishing in Oklahoma’s rivers and streams provides a unique experience for anglers in the state. Despite its popularity, information on total demand and economic benefits associated with stream fishing is limited in the state. Research on the role of site quality indicators, such as fish size and quantity, on recreational fishing has shown mixed results. Whether fish size or quantity plays an important

Stream fishing plays a key role in provisioning services for obtaining fish, and also provides cultural services in terms of enjoyable walking along streams while listening to the sounds of flowing water. However, in Japan, the economic value of stream fishing has been emphasised mainly from the viewpoint of the fishing industry. Few attempts have been made to estimate the socioeconomic importance

Parapenaeopsis stylifera (H. Milne Edwards, 1837), popularly known as Kiddi shrimp, constitutes an important fishery resources along the Indian coast with wide geographical distribution. Despite its economic importance, the genetic stock structure of the species is not investigated so far. Knowledge on genetic structure is essential for formulating sustainable management and conservation measures.

Shortfin mako sharks, Isurus oxyrinchus, were listed under Appendix II of CITES in 2019 in part due to the results of the last stock assessment for the North Atlantic population, which determined the population is overfished and experiencing overfishing. With population numbers expected to continue to decline, the managing body, the International Commission for the Conservation of Atlantic Tunas (ICCAT)

Tropical fish stocks are perceived not to exhibit seasonality in growth. For this reason the standard von Bertalanffy growth function (VBGF) has been used widely to fit the growth of tropical fish populations compared to the seasonally-oscillating VBGF (soVBGF), which is seldom used in tropical fisheries. To advocate for the use of the soVBGF in assessment of tropical fish stocks, this study compared

Considering that stock assessment requires iterative work including exploratory calculations and discussion, efficiency in completing projects is the key to a successful contribution to stock management. However, if the production speed of each process of the project is inconsistent, a faster process may be worse than a slower process because a large amount of information produced by a faster process

Atlantic herring was commercially captured with purse seine in catches of 100–400 Mt. During crowding 0–30 min individual fish were sampled from the purse seine, killed by a percussive blow to the head and blood lactate was measured. Muscle pH and rigor index was measured over 24 h. Additionally, 100 fish sampled before and after crowding were stored in tanks, filleted, and analyzed for flesh quality

Identifying spawning sites of fish often involves extensive egg and larval sampling surveys over potential spawning sites, or by backward-tracking advected larvae to their source. Due to the vastness of the Barents Sea capelin spawning areas, back-tracking methods have limited application. Egg and larval surveys that provide information about spawning sites have also been discontinued in recent years

The main Hawaiian islands Deep 7 bottomfish fishery is a multispecies fishery that uses hook-and-line gear to catch seven primary species and is currently managed and assessed as a single population. Management plans support, and recent assessment reviews recommend, assessing species on an individual basis. When fisheries catch multiple species, but information about abundance is desired for a single

Naturalized rainbow trout (Oncorhynchus mykiss) populations are an important recreational fishing resource in the Araucanian lakes of southern Chile, but few reproductive studies have been undertaken to assess their sustainability. It is important to address this issue, since this analysis may provide information for improving management activities. In this study we carried out a biometric and reproductive

The northeast US fishing industry and other stakeholders have considerable interest in the quality of bottom trawl survey results because of their importance in the setting of quotas, especially those directly derived from bottom trawl indices measured in catch per area swept by the survey net. Net spread (also referred to as wing spread) impacts catches and thus indices and, for the federal northeast

Over the last decade, an increase in the annual rate of shark bites on people has stimulated the development of new techniques aimed at reducing their occurrence, while minimising negative impacts to marine wildlife. One such technique is the SMART (Shark-Management-Alert-in-Real-Time) drumline, which allows for the capture and relocation of white sharks (Carcharodon carcharias), bull sharks (Carcharhinus

In the southern Gulf of St. Lawrence (sGSL), there is a mostly supplementary fishery for sea scallops (Placopecten magellanicus) concentrated on three primary scallop beds in the Northumberland Strait. The fishery is not subject to an enforced minimum size limit and small scallops (<90 mm shell height) are often removed from this population before they have had time to adequately contribute to population

The beam trawl fishery targeting sole is known for their substantial bycatch of flatfish below the minimum landing size. Pulse trawls were developed to improve the selectivity by replacing mechanical stimulation with electrical stimulation which immobilises fish in front of the footrope. Results are presented of an experiment on board of a commercial pulse trawler studying the effect of electrical

Tag recovery studies are commonly used to estimate survival and exploitation of fish populations. Angler nonreporting and tag loss can cause estimates from such studies to be biased. In this study high-reward tags and double-marking were used to estimate reporting and tag retention rates for Walleye Sander vitreus marked with Monel metal jaw tags. As a secondary mark, a dorsal spine was removed from

As live release black bass (Micropterus spp.) tournaments increase in popularity, stress associated with live-well confinement may result in increased mortality rates. Variation in number of bass in tournament angler live-wells is common due to a suite of factors (e.g., regulations, number of anglers per boat, angler success), but the effect on delayed tournament mortality relative to other environmental

With the development of satellite technology, vessel monitoring has entered a new era. In this study, through a comparison with better-recorded fishing logs, we analyzed the performance of vessel monitoring system (VMS) and nightly satellite data in monitoring fishing activities of a large-sized falling net vessel mainly targeting the purpleback flying squid (Sthenoteuthis oualaniensis) in the open

This paper deals with mathematical modelling of strategies in harvesting of fish populations. Since too aggressive harvesting may have severe consequences, a cautious control of the process is called for. The determination of optimal harvesting based on the biomass size is made even more challenging since there is considerable uncertainty in the estimation of the stock size, the so-called incomplete

The deep demersal snapper-grouper fishery in Indonesia is a data-poor fisheries resource that provides food security and a source of income to millions globally. Owing to an ongoing crew-operated data recording system implemented in Indonesia since 2015, the stocks of this fishery can now be assessed using length-frequency data and updated life-history parameters. Here, we use two length-based methods

The Chishui River is the first to have a complete fishing-closure in the Yangtze River basin. To explore how fish assemblages changed following the implementation of the fishing closure, field surveys were conducted biannually in three reaches (upper, middle and lower) along its longitudinal gradient during 2007 to 2019. A total of 143 species from eight orders and 24 families was collected. Diversity

Within fisheries, stakeholders often have varying viewpoints regarding natural marine resources, and use different sets information to evaluate their condition. Evaluating a resource with different sets of information can lead to different conclusions. Windowpane flounder (Scophthalmus aquosus) are a managed finfish species in the northwest Atlantic whose regulations have the potential to limit harvest

Fisheries stock assessments have traditionally modeled age and size composition data using the multinomial likelihood, however the multinomial cannot appropriately account for the correlations and overdispersion that exist in the observed data or in the model residuals. Not accounting for these phenomena can affect assessment performance. Methods to remedy this have included down-weighting composition

Integrated stock assessments depend on reliable catch and observational data to produce unbiased estimates of fish stock biomass and productivity. However, biases in catch data due to unreported catch are common among many of the world’s fisheries, especially those that are high value and therefore more vulnerable to illegal fishing. Some of these fisheries rely on tag-recapture data to support the

Trace elements integrated into fish fin rays from the ambient environment may represent a permanent record of the environmental conditions that an individual has experienced throughout its lifetime. Fish from hatcheries used for stocking may therefore carry a natural intrinsic tag of their origin, which can be then later used for assessing the efficiency of stocking measures. This study investigated

Warsaw grouper (Hyporthodus nigritus) in the Gulf of Mexico (GoM) are currently managed as a single-stock; however, patchy distribution of suitable habitat may promote the development of discrete populations with different life history characteristics thereby complicating conservation policy. We estimated ages and age-length relationships of Warsaw grouper from different geographic regions in the GoM

Assessment and monitoring of marine biodiversity, including fish populations, is essential for evidence-based conservation management of coastal marine resources. The effectiveness of monitoring techniques for stock assessment varies with sea conditions. In dynamic marine environments with high turbidity, such as those found in estuaries, mangroves, coastal straits, fjords, and bays, traditional assessment

The hypothesis that salinity and temperature influence otoliths of Atherinella brasiliensis populations was investigated by comparing the morphologies and shapes of otoliths from two contrasting estuaries (positive and hypersaline). Overall, 462 otoliths were extracted from adult fish collected in both estuaries. For each otolith, the morphometric measurements (height, width, and length) and were recorded

Bycatch of protected species, particularly small cetaceans, in gillnets is a worldwide concern. One hypothesis for this is that echolocating cetaceans entangle because they do not perceive conventional gillnets as impenetrable barriers, owing to the gillnet’s faint echo. A gillnet modified for improved acoustical visibility was tested in a first pilot trial in a commercial gillnet fishery targeting

The giant Antarctic toothfish Dissostichus mawsoni is one of the most economically valued fishery resources from the Southern Ocean. However, the distinctive biological characteristics and life history of this species, including large body size, long life span, late sexual maturity, and specialization to freezing polar waters, make it particularly vulnerable to overfishing and global climate change

Fishing activity in the Amazon basin has been declining in regards to fish production and the diversity of the catch has been altered due to anthropic interferences due to hydro-electric dams built on the main rivers of this region. Data were collected regarding the landings of the fisheries together with the fishing colonies in the Guaporé River basin for the decade before and after 2009. This benchmark

Data Envelopment Analysis (DEA) studies of fisheries usually apply output oriented capacity utilization based on physical measures. Although physical measures capture important input factors employed in fishing activities (such as boat size, engine power), economic measures directly reflect the cost of inputs employed. This case study investigates whether economic measures are vital or whether capacity

Numerous studies have investigated the impacts of catch-and-release on the post-release behaviour of fish during periods characterized by warm air and water temperatures. Comparatively little is known about the post-release behaviour of fish caught while ice fishing. Largemouth bass (LMB), a popular sportfish in North America, is sometimes encountered during ice fishing and is often released due to

We consider the challenge in estimating the natural mortality, M, in a standard statistical fish stock assessment model based on time series of catch- and abundance-at-age data. Though anecdotal evidence and empirical experience lend support to the fact that this parameter may be difficult to estimate, the current literature lacks a theoretical justification. We first discuss the estimatability of

The swimming crab is an important commercial fishery species in China, Korea and Japan. Overfishing and destruction of habitats in coastal waters mean that the natural resources cannot meet the swimming crab’s increased demands for food, caused by large-scale stock enhancement in Liaoning, China over the last eight years. The genetic response of the local wild populations to such a large-scale release

Increased foraging activity increases vulnerability of fish to angling. Foraging activity of free-ranging common-carp (Cyprinus carpio L.) is assumed to be mostly nocturnal. Thus, it is assumed that the number of carp caught in angling competitions will be higher during the night than during the day. Also, common carp are able to learn the position of new feeding spots that they exploit repeatedly

The Southern and Eastern Scalefish and Shark Fishery (SESSF) is the main domestic supplier of fresh wild-caught fish to the Sydney and Melbourne markets. The fishery is managed through a series of total allowable catches (TACs) for key species, with an objective of achieving maximum economic yield (MEY) with biomass and fishing mortality at MEY as management targets. However, the sensitivity of seafood

In China, fisheries include a combination of capture and aquaculture activities. In the context of China Fisheries and Aquaculture Statistics Yearbooks, the fisheries sector includes three economic sub-sectors: the fisheries primary sector (e.g., saltwater or freshwater, wild or farmed capture, and aquaculture), the fisheries secondary sector (e.g., aquatic processing, fisheries machine and tools manufacturing

Identifying the nursery origins of individual Pacific halibut (Hippoglossus stenolepis) is critical to a refined understanding of regional productivity, the effects of environmental forcing on population dynamics, and the spatial impacts of mortality and bycatch. Otolith microchemistry may provide a tool for identifying fish origins, but a precursor to using microchemistry-based assignment models is

The Potential Biological Removal (PBR) level serves as a threshold for management of marine mammal–fishery interactions under the US Marine Mammal Protection Act. The PBR protocol involves classifying fisheries based on the ratio of recent average bycatch mortality to PBR. A simulation-based framework is developed that quantifies the probability of incorrectly concluding that average bycatch mortality

Much emphasis has been placed on challenges related to estimating ages of old fish, yet accurately estimating age for young individuals has proved equally challenging for some species. Indices of recruitment are often based on assigning ages to young fish to estimate the strength of a given year class. Similarly, growth is most commonly estimated using age-based methods and has been proposed as a metric

Pikeperch (Sander lucioperca L.) is an important species for European aquaculture and recreation fisheries. The wide range overexploitation of its stock highlights the importance of supporting wild stocks, within its native range. Our study was therefore addressed to test the effectiveness of different artificial spawning nests in a natural habitat. Eight types of artificial nests, characterized with

Stock assessments are a key requirement supporting the sustainable harvest of fisheries resources globally. In this study, the population of an important south-eastern Australian halfbeak, Hyporhamphus australis targeted by a lampara-net fishery was assessed via hazard functions within a Bayesian framework (that was also compared to maximum likelihood). Fifteen-years of yield, effort and size-at-age

Sharks play important ecological roles in marine ecosystems. However, due to their life-history traits and low resilience, their vulnerability increases with overexploitation. The Eastern Pacific Ocean (EPO) purse-seine fishery catches several pelagic sharks as bycatch. Therefore, describing the environmental preferences of bycaught sharks is crucial to improve fisheries management. This study aims

The practice within recreational fisheries to release captured fish back to the wild, known as catch-and-release (C&R), is an increasingly important strategy to protect fish stocks from overexploitation. However, C&R is a stressor and since animal reproduction is particularly sensitive to stress there is reason to suspect that such a practice induces sublethal fitness consequences. Here, we investigated

Stock assessment models often require an external estimate of the natural mortality rate (M) that is usually assumed to be the same for all ages and years in the model. Although the fixed M assumption can be a major oversimplification, model diagnostics (e.g. profile likelihoods) that can help provide an understanding of how the choice of M affects model fit are often not used in practice. In the state-space

Forage fish and fish associated with particular benthic habitats (e.g., rockfishes, sand eels, sand lances) may be particularly difficult to assess through standard survey methodologies. Stereo-cameras, video, and automated visual data may serve as useful complementary tools to provide insight into the dynamics of these species. Visual methods may be used not only to estimate abundance and distribution

Biological body parameters of adult male West Coast rock lobsters, Jasus lalandii, of commercial size were analysed over two years to determine reserve accumulation during two moult (i.e. growth-) cycles. Two fishing areas were compared that were historically known for fast- and slow growth, respectively. In addition, setagenic development for moult stage determination and the biochemistry of the hepatopancreas

Catch-and-release is practiced in recreational fisheries under the premise that released fish will survive with negligible injury and stress. However, hooking injuries may prevent that outcome from being realized. One way to potentially minimize injuries and maximize survival in angled fish is to replace treble hooks on hard plastic lures with single hooks, but the effectiveness of this tactic has

For commercially important permits and pompanos, scant official information exists on fishery assessments, the reproductive seasonality and location of these species, which impede knowing the intensity of fishing pressure imposed at their spawning grounds. Fishers have acquired a substantial body of knowledge on these species as a result of their exploitation, which typically occurs at spawning aggregation

This study aimed to understand the size-specific spatiotemporal dynamics of bigeye tuna (Thunnus obesus) in the eastern Pacific Ocean from 1991 to 2017. A spatiotemporal delta-generalized linear mixed model was applied to catch rate data by size class collected from a Japanese longline fishery. The results showed that the density of bigeye tuna varied spatially across the eastern Pacific Ocean, with spatial

Trade in elasmobranch products is a circum-global practice negatively impacting elasmobranch populations. Although Asia is at the centre of the shark fin trade, countries like Bangladesh, remain data-poor regarding trade dynamics. In the Bay of Bengal region, Bangladesh has a long-standing history of producing and trading products from vulnerable and protected elasmobranchs both nationally and internationally

Many exploited coastal species rely on estuarine nurseries, however, the importance of different estuaries and their contribution to exploited populations can vary. Identification of connectivity between source nurseries and exploited populations is important for effective habitat and fishery management. We present a case study which employs otolith chemistry to investigate source-sink population dynamics

Model-based prediction of fish distribution at fine resolutions in space and time has the potential to inform area-based and dynamic forms of management, such as permanent marine protected areas or real-time temporary closures. A major limitation to the spatial and temporal mapping resolution that is achievable is the amount of high quality, standardised data that can be utilized for fitting statistical

Highly variable recruitment and a complex harvest strategy resulted in dramatic inter-annual changes in historical catches, including prolonged closure periods, for Bering Sea Tanner crab (Chionoecetes bairdi). Current management regulations, linked to recent frequent closures, led to an industry-initiated cooperative effort to reevaluate the harvest control rule (HCR) that forms part of the State

The seasonal and inter-annual variability in abundance of the main “local tropical tuna resources” in the EEZ of Côte d'Ivoire was analysed with catch and effort data from French and Spanish purse seiners over the period 2000–2019. A seasonal spatio-temporal model developed by Thorson et al. (2020a) was used to estimate abundance indices for the main tropical tunas by commercial category (<10 kg and>