Main Commercial Fish Species Research Articles

Mercury content and consumption risk of the invasive Arapaima gigas (paiche) in Bolivia

Mercury is a global pollutant present in the environment. The most frequent non-occupational human exposure pathway is fish consumption. Generally, fish species of large size and with carnivorous or omnivorous feeding habits have higher mercury concentrations. The invasive fish Arapaima (popularly known as paiche), an omnivorous large-sized species introduced in northern Bolivian Amazon about 50 years ago after escape from aquaculture in Peru, has successfully colonized this region and is now the main commercial fish species. Consumption of this species in Bolivia is increasing, and an evaluation of the risk of mercury exposure for human health is warranted. Muscle samples from 86 fish were taken from four different sub-basins (Orthon, Madre de Dios, Beni and Yata). 8.1% of the samples showed mercury content above the safe consumption recommendation of the World Health Organization (0.5 mg kg-1). Samples from the Madidi and Yata rivers scored the highest mean concentrations (0.367 and 0.306 mg kg-1, respectively), whereas individuals from the lower Beni subbasin showed the lowest (0.105 mg kg-1). According to our results, the maximum recommended paiche meat consumption is 316 g per week, divided into two meals, which is in agreement with international recommendations for fish consumption (227 g to 340 g per week), although this can vary according the place of origin of the meat. Following these recommendations, mercury exposure through paiche consumption should not represent a risk for human health.

Fisheries and biological characteristics and state of stocks of the main commercial fish species in Beloye Lake

The current composition of the ichthyofauna and the importance for fisheries of the main fish species in Beloye Lake (Vologda Region) is described in the article based on research materials from 2018 – 2022. The biological features and commercial use of twelve most valuable fish species are summarized as result of the composition of industrial and research catches studies. The size and age composition of catches, the age of puberty, the timing and conditions of spawning, and the feeding patterns of fishes were studied. The influence of net fishing gear with different mesh spacing on commercial fish populations and the magnitude of nets fishing productivity (fishing effort) were studied for the first time. The role of the most important fish species for industrial fisheries in Beloye Lake was assessed.

Status of the fish stocks and fisheries of the main commercial fish species of Lake Ladoga in the XXI century

In the 21st century, there has been decrease in stocks and catches of aquatic biological resources in Lake Ladoga as well as a change in the structure of the fish population in the Lake, primarily due to changes in the trophic capacity of the reservoir. Smelt dominates in the commercial catches. Stocks and catches of autumn-spawning whitefish and lakecisco show obvious downward trend. Biological and commercial indicators of the pike-perch population are at a low level. Stocks of bream, roach and perch are in good condition.

Cross-habitat utilization of fish in a tropical deltaic system as a function of climate variability and body size: Are mangroves fish nurseries in a tropical delta?

The temporal variability of fish habitat utilization is poorly understood in tropical deltaic systems due to high water turbidity, which limits visual censuses, and to the lack of long-term data incorporating climate variability events. We aimed to assess the influence of body size and El Niño Southern Oscillation (ENSO) variability on the cross-habitat utilization rate of 14 fish species of commercial relevance in the Ciénaga Grande de Santa Marta (CGSM). We estimated the utilization of mangroves and coastal lagoons based on relative catch frequencies from encircling gillnets used within a long-term catch monitoring program, and then tested for significant changes in each species' habitat utilization as a function of body size and climate variability. Six species showed a high dependence on mangroves and four on coastal lagoons for most body size classes (including juveniles) and ENSO conditions. One species (Elops smithi) showed a high utilization of mangroves in some ENSO phases and body size classes, while three species showed a high utilization of both mangroves and coastal lagoons. Mangrove utilization by six species (Megalops atlanticus, E. smithi, Centropomus undecimalis, Mugil incilis, Mugil liza, and Ariopsis canteri) increased in larger body sizes at low depths, which usually occurs under dry ENSO conditions, when predatory risk is higher in coastal lagoons. Another species (Caquetaia kraussi) increased its mangrove utilization from the body size at which its feeding habits change. Mangroves and coastal lagoons are important nurseries and habitats for adults of the main commercial fish species in the CGSM. Seascape habitats and fringe/riverine mangroves must be conserved in tropical deltas to promote not only nurseries but also fish lifecycles.

Stock dynamics and biological indicators of the main commercial fish species of the Kuibyshev reservoir for the period 2001–2021, their development by fishing

Based on materials from resource studies 2000–2021 a review of the dynamics of stocks and biological indicators of the main commercial fish species of the Kuibyshev reservoir was prepared. The data on their development by trade are given. The reserves of biological resources of this reservoir are shown. Recommendations on rational use are given: it is proposed to increase the catch of roach, silver bream, perch, crucian carp, blue breeze and other underutilized species, which will make it possible to obtain an additional 400 tons of high-quality fish.

Stock dynamics and biological indicators of the main commercial fish species of the Nizhnekamsk reservoir for the period 2001–2021, their development by fishing

Based on research materials from 2001–2021 a review of the dynamics of stocks and biological indicators of significant fish species in the fishery of the Nizhnekamsk reservoir was prepared. Data on their stocks, catches by users are given, and the resource potential of the reservoir is shown. Recommendations are given on the rational use of aquatic biological resources of the reservoir, it is proposed to increase the catch of roach, silver bream, perch, crucian carp, blue bream, tench and other underutilized species by 20%, which will allow obtaining additional high-quality freshwater fish.

Dynamics of stocks and biological indicators of the main commercial fish species of the Ivankovo reservoir for the period 1998–2021, their development by fishing

Ivankovskoe reservoir, the oldest of the cascade of Volga reservoirs. Based on research materials from 1998 to 2021, a review of the dynamics of stocks and biological indicators of the main fish species of the Ivankovo reservoir has been prepared. Data on their stocks and catch by users are given, the resource capabilities of the reservoir are shown. Recommendations are given on the rational use of aquatic biological resources of the reservoir, it is proposed to resume industrial fishing and increase the catch of roach, grouper, perch, crucian carp, tench, etc. underutilized species by 20%, which will allow obtaining additional high-quality freshwater fish.

Stock characteristics, dynamics and efficiency of using of the main commercial fish species, prospects of catching at the Gorky reservoir

Based on the materials of resource studies in 2003–2021 and stock databases of the Nizhny Novgorod branch of the Federal State Budgetary Scientific Institution «VNIRO», a history review of the development of the fisheries, the dynamics of stocks and biological indicators of the main commercial fish species of the Gorky Reservoir has been prepared. Data on the development of stocks of aquatic biological resources by industrial fishing are given. The water biological resources reserves of the reservoir are shown, which at least make up about one third of the modern industrial production (about 150 tons). Recommendations on rational management of fisheries are given.

The initial assessment of an important pelagic fish, Mackerel Scad, in the South China Sea using data‐poor length‐based methods

AbstractObjectiveScadsDecapterusspp. occur widely throughout tropical, subtropical, and temperate oceans and are both economically and ecologically important species. They are among the main commercial fish species caught by the light falling‐net fishery in the South China Sea, which is dominated by Mackerel ScadDecapterus macarellusand Shortfin ScadD. macrosoma. Stock assessment is an approach used to guide effective management and maintain fishery sustainability.MethodsTwo data‐poor methods, namely length‐based Bayesian biomass estimation and length‐based spawning potential ratio, were applied to assess the status of Mackerel Scad, the most dominantDecapterusspecies in the South China Sea. Electronic length–frequency analysis was used to estimate von Bertalanffy growth parameters (asymptotic lengthLinfand growth coefficientK) to serve as priors.ResultThe results show the estimatedLinfandKof Mackerel Scad in the South China Sea as 36.0 cm and 0.37/year, respectively. Estimated natural mortality was 0.74/year, and mean fork length at 50% sexual maturity was 24.29 cm. Length‐based Bayesian biomass estimation analysis showed that the estimated relative stock size had decreased from 1.3 in 2012–2014 to 0.7 in 2019–2021, indicating an overfished status. Length‐based spawning potential ratio analysis showed that the estimated spawning potential ratio for this fishery decreased from 13% to 12%, which is significantly below the limit reference point of 20%.ConclusionOur results obtained through length‐based methods indicate the lower SPR of Mackerel Scad stock was due to catching an excess of juveniles. Therefore, we highlight the need to increase the minimum mesh size in the fishing nets and strengthen international cooperation for conserving this shared stock in the South China Sea.

Mercury content in commercial fishes of the Barents Sea (based on long-term data)

The aim: to study the amount of mercury found in muscle tissue and liver of the main commercial fish species of the Barents Sea.Research material was comprised of fish samples collected during the expeditions of “PINRO” named after Knipovich in the Barents Sea in 2009-2020. The study was based on muscle and liver samples taken from cod, haddock, long rough dab, Greenland halibut, plaice and spotted catfish. Over 1500 samples were analyzed. Novelty: for the first time a comparative analysis of Hg concentration in six commercial fish species of the Barents Sea was run and background readings were provided using such a big amount of data.Methods used: the total content of Hg in fish samples was measured using Shimadzu (Japan) Cold Vapor Atomic Absorption Spectrophotometer (CVAAS). Statistical data processing and charting were done using MS Excel and application software package of Statistica 13.Results: it was shown that the mean amount of Hg in muscle and liver of the studied fish was below the maximum concentration of 0.5 pg/g of wet weight acceptable by sanitary standards. Content of Hg in liver was two times higher than in muscle. No evidence of anthropogenic contamination of the studied species by mercury was found. The total content of Hg in muscle and especially in liver demonstrated a considerable variability, which is probably linked to seasonal changes in the diet. There might be other factors influencing the mercury concentration, such as taxonomic affiliation, regional peculiarities, physiological state, and fattiness.Practical significance: the acquired results were used to determine whether the commercial fishes meet the sanitary standards used in Russia.

Extraction and characterisation of type I collagen from the skin offcuts generated at the commercial fish processing centres.

Effective use of underutilised fish processing by-products could open avenues for new industries if they are used to extract high-valued bioactive compounds. Therefore, discarded skin offcuts of three main commercial fish species of Sri Lanka were used to extract collagen with acetic acid and the extracted collagen was evaluated for industrial suitability. The yields of acid-soluble collagens from Yellowfin tuna (Thunnus albacares), Seer fish (Scomberomorus commerson) and Asian sea bass (Lates calcarifer) were 61.26%, 58.21% and 59.31%, respectively on a dry-weight basis. Fourier Transform Infra-Red spectra and X-ray Diffraction spectra confirmed that all collagens were in type I and preserved the native triple-helical structure during extraction. The UV absorption spectra confirmed a high collagen purity in all species. These results confirm that the extracted collagen consists of the characteristics required for collagen-based industries such as food, pharmaceutical, and biomedical. The high availability of skin offcuts from the processing industry and the higher collagen yields revealed in this study confirm the possibility of using discarded skin offcuts of the three fish species as a potential source of type I collagen for industrial purposes.

СУЧАСНИЙ СТАН ОСНОВНИХ ПРОМИСЛОВИХ ВИДІВ РИБ КРЕМЕНЧУЦЬКОГО ВОДОСХОВИЩА

The major quantitative and qualitative indicators of the main commercial fish species of the Kremenchug reservoir were analyzed in the study and the main parameters of the optimal commercial fisheries catch by gill nets were determined. Original materials for investigations were data of control commercial catches in the Kremenchug reservoir during 2021. Conservative techniques were used in sampling and analysis during ichthyological studies.
 Materials on the main commercial fish species in the Kremenchug reservoir were collected. Biological materials from commercial gill nets were selected and the fish productivity of the reservoir was determined.
 The work provides up-to-date information on the main biological indicators of commercial fish species of Kremenchug reservoir in modern conditions of anthropogenic press and calculates scientifically proven parameters of optimal commercial fish harvest.
 The article can be used by scientists, practitioners, fisheries patrol and the State Ecological Inspectorate to predict future catches and knowledge of the current situation with the main industrial fish species in the Kremenchug Reservoir. Modern material on the main commercial fish species will help to see the real picture in the reservoir and take necessary fish protection measures.

BIOLOGICAL CHARACTERISTICS OF THE FISH FAUNA IN THE SEVERNAYA DVINA ESTUARINE AREA

The Severnaya Dvina is rightfully considered one of the largest rivers in Russia’s European North and is the main catchment for fisheries in the Arkhangelsk Region. Its lower course is under enormous pressure from numerous pollution sources located along its tributaries and in the estuary. This situation leads to changes in fish habitat conditions, their species diversity, as well as biological parameters, population structure, population dynamics, and stock. This article presents the results of a study of the fish population in the estuarine region of the Severnaya Dvina in 2019 by classical ichthyological research methods using passive (stake nets) and active (draft nets) fishing gear. The species composition and taxonomic diversity of the fish fauna are presented. We determined the affiliations of the fish with faunistic complexes and ecological groups differing in dietary and natural reproduction characteristics (spawning substrates, egg-laying methods, and spawning periods). The economic significance of the fish fauna was assessed, rare and scant fish species listed in the regional Red Data Book were identified. The biological characteristics (length-weight structure, age and sexual composition) of the populations of the main commercial fish species are described. The dietary habits of the two most important species groups, coregonids (whitefish) and cyprinids (bream), are considered. The fish species diversity in the Severnaya Dvina estuary is quite high. The list totals 36 fish species. The biological characteristics of the fish were found to be within the average range for the given species. The commercially important whitefish and bream are benthos feeders (potential competitors for food). But the tension of this competition is reduced due to their different dominant feed items.

Mapping and Assessing Commercial Fisheries Services in the Lithuanian Part of the Curonian Lagoon

The spatial distribution of biomass of main commercial fish species was mapped to estimate the supply of a provisioning fishery service in the Curonian lagoon. Catch per unit effort (CPUE) was used as a proxy to estimate the efficiency of commercial fishing and, subsequently, the potential biomass of fishes. The relationship between distinctive characteristics of the fishing areas and corresponding commercial catches and CPUE was analyzed using multivariate analysis. The total catch values and CPUE used in the analyses were derived from the official commercial fishery records. RDE analysis was used to assess the variation of both catch and CPUE of commercial fish species, while the percentages of bottom sediment type coverage, average depth, annual salinity, and water residence time in each of the fishing squares were used as explanatory variables. This distance e-based redundancy analysis allowed for the use of non-Euclidean dissimilarity indices. Fisheries data spatial distribution map indicated the lack of coherence between the spatial patterns of commercial catches and CPUE distribution in the northern part of the lagoon. Highest CPUE values were estimated in the central-eastern part of the lagoon as compared to the western part of the lagoon where CPUE values were substantially lower. Both total catch and CPUE appeared not to be related to the type of bottom habitats statistically while being spatially correlated in-between. However, the impact of salinity and water residence time calculated using the 3D hydraulic circulation model on the distribution of both CPUE and commercial catches was statistically significant.

Analysis of nowadays fisheries and the recommendations of the regulation of the main commercial fish species stocks exploitation in the Dniestrovskiy liman

The dynamics of the catch of the main commercial fish species of the Dniesterovskiy liman are presented. The sizeage composition of the gibel carp Carassius gibelio (Bloch, 1783), common carp Cyprinus carpio (Linnaeus, 1758), common bream Abramis brama (Linnaeus, 1758), roach Rutilus heckelii (Nordmann, 1840) and common pike-perch Sander lucioperca (Linnaeus, 1758) from commercial catches in the Dniesterovskiy liman in 2012–2021 was analyzed. The obtained data were used to analyze the state of fish stocks and to obtain the recommended optimal indicators of their exploitation using modern models BSM, LBB and LB-SPR. The overexploitation of gibel carp in the Dniesterovskiy liman was observed accordingly BSM, LBB and LB-SPR results. A sharp increase in the level of exploitation of gibel carp has led to its stock decline. The level of common carp exploitation in 2018–2021 has approached the optimal value. The currently state of its population in the Dniesterovskiy liman is relatively good. Commercial exploitation of the common bream and roach remains at an excessive and at a relatively moderate level respectively. The catch and CPUE of the pike perch have been declined significantly in recent years. The stock of this species is in a very unfavorable condition. The recommendations for further use of the main commercial fish species in the Dniesterovskiy liman are given. Accordingly obtained results the value of the maximum sustainable yield (MSY) of gibel carp is 813 tons with the optimal average commercial length in the catch – 18.5–19 cm. MSY of common carp is set at 92.7 tons with the optimal length in the catch – 39.9 cm, common bream – 148 tons with an optimal length in the catch no less than 30.0 cm. MSY of roach is set at 57.7 tons. The value of pike perch biomass is significantly lower than the critical value of Bpa=0.5 BMSY – its catch should not exceed 5 tons. The strict compliance with the Rules (1998) and Regimes of commercial fishery, as well as commercial fishing regulating by limiting the use of fishing gear are the most effective methods of the abundance increasing and rational use of water biological resources of the Dniesterovskiy liman.

THE STATE OF THE ICHTHYOFAUNA OF THE SELETA RIVER

The Silety River originates in the territory of Akmola region near the village of Bozaygyr in the Shortandinsky district and flows into the lake Silety-Teniz, located on the territory of the Ualikhanov district of the North Kazakhstan region. In a number of localities, the Silety River is a drinking reservoir. In addition, the Silety river is of great recreational importance, and serves as a place for amateur fishing. In a number of localities, the Silety River is a drinking reservoir. In addition, the Silety river is of great recreational importance, and serves as a place for amateur fishing. In a number of localities, the Silety River is a drinking reservoir. In addition, the Silety river is of great recreational importance, and serves as a place for amateur fishing. All mass species of fish living in the Sileta River, they are found throughout its entire length, thus, the composition of the commercial ichthyofauna has similarities in all commercial areas. The article provides information about the features and current state of the ichthyofauna of the Sileti River. The assessment of the current state of stocks of the main commercial fish species is given.

Length-Based Assessment of Fish Stocks in a Data-Poor, Jointly Exploited (China and Vietnam) Fishing Ground, Northern South China Sea

The Beibu Gulf is one of the most important fishing grounds in the South China Sea (SCS), and the fisheries resources in this area are exploited by both China and Vietnam. In recent decades, some indications of overfishing have appeared, including declining catch rates, frequently changing catch composition, and shrinking body sizes in main commercial fish species. Due to limited data availability, only a small subset of exploited fish stocks in this area has been assessed. Here, we applied two length-based methods, electronic length frequency analysis (ELEFAN) and length-based Bayesian biomass estimation (LBB), to stock assessment of nine exploited fish species in the Beibu Gulf. There were total 53, 652 length records of 30 target stocks used in this study during the survey period from 1960 to 2015. The results showed that the two length-based methods presented different ability in estimating exploitation rate (E), and the estimated E ranged from 0.34 to 0.87 using ELEFAN method while ranged from 0.26 to 0.86 using LBB method. The prior information from ELEFAN method was effective for LBB method, as there were significant differences in 66.7% of the 30 target stocks in estimated Linf, and 93.3% in estimated B/BMSY, using LBB method with and without prior information. The estimated Lc/Lc_opt and B/BMSY of LBB method suggest a pressing situation for the fisheries in the Beibu Gulf, as 86.7% of the 30 target stocks had been suffering from growth overfishing (Lc/Lc_opt < 1), and 83.3% had been overexploited or fully exploited (B/BMSY ≤ 1.2). In addition, we suggest using both ELEFAN and LBB methods to fit length-frequency data of data-poor fish stocks because they are complementary in estimating management reference points. We also emphasize collaboration mechanism should be established by China and Vietnam for the sustainability and recovery of fishery resources in the Beibu Gulf.

DNA barcoding reveals fraud in commercial common snook (Centropomus undecimalis) products in Santa Marta, Colombia

The common snook Centropomus undecimalis is one of the main commercial fish species in the Caribbean region, including Colombia, where its populations have drastically decreased due to overfishing and environmental degradation. Thus, there is a market imbalance between the availability of snook products and their demand by consumers, which creates an opening for fraudulent actions such as species substitutions. Legislation in Colombia (and most Caribbean countries) lacks effective tools for the easy and rapid detection of frauds. Furthermore, there are very few studies published in scientific journals addressing this issue, of which none include C. undecimalis as the target species. Therefore, in order to investigate the existence of mislabeling in common snook products in Santa Marta, the present study analysed 44 frozen snook fillets from the five commercial brands available in the city. Moreover, 15 fresh snook fillets from six of the main fish markets were also analysed. To discover the frequency of possible frauds in labeling, samplings were carried out in July, September and November of 2019. Sample analyses involved the identification of each fillet at species level through molecular barcodes (16S-rRNA and COI), whose sequences were verified using BLAST and BOLD, and corroborated by a phylogenetic analysis. As a result, an astonishing 98% of the supermarkets fillets were found to be fraudulent, contrasting with a single case registered in the fish shop samples. The species used to substitute snook include the Pacific bearded brotula Brotula clarkae (38 samples), the Nile perch Lates niloticus (4 samples) and the acoupa weakfish Cynoscion acoupa (1 sample). Based on these results, there is a high rate of fraudulent labeling in the marketing of common snook in the city of Santa Marta, which calls for urgent actions to be taken by the corresponding authorities.

АНАЛИЗ СОСТОЯНИЯ ЗАПАСОВ ОСНОВНЫХ ПРОМЫСЛОВЫХ РЫБ КУЙБЫШЕВСКОГО ВОДОХРАНИЛИЩА ЗА ПЕРИОД 2000–2018 ГГ. И ЭФФЕКТИВНОСТЬ ИХ ИСПОЛЬЗОВАНИЯ ПРОМЫСЛОМ

The article presents a review of the main commercial fish stocks of the Kuibyshev Reservoir based on the long-term research data (2000–2019). The Kuibyshev Reservoir is the leading fishery reservoir in the Republic of Tatarstan, Mari El, Chuvashia, Ulyanovsk and Samara Re-gions. There have been given the data of regular observing species, sex, size-weight and age composition of fish, their reproduction efficiency, distribution, abundance and reproduction of aquatic biological resources, their habitat, as well as control over their fishing and conservation. The analysis of the influence of environmental factors (level and temperature regimes) and fishing on the fish stocks formation is presented. Based on the presented materials, there have been shown the data about the stocks of the main commercial fish species of the Kuibyshev Reservoir (bream, zander, pike, carp, catfish, sterlet) and of the small-sized ordinary fish stocks, the optimal development of which will bring the catches up to 10 thousand tons and more. It has been inferred that for rational fishing in the reservoir, it is necessary to develop a strategy for the integrated effective development of biological resources of the reservoir on an ecosystem basis for better use of the bioproduction capabilities of its biological resources.

Промыслово-биологическая характеристика сиговых рыб бассейна р. Пясины

This publication presents the results of ichthyologic studies obtained during
 the inventory of the flora and fauna of the Pyasina river and The pyasinsky
 Bay of the Kara sea in 2016-2018. The organizer of the work is the Federal
 state budgetary institution "United Directorate of Taimyr nature reserves".
 The observed size and age characteristics of muksun, nelma, whitefish,
 and chira are presented. Their demographic characteristics are shown. The
 existing fishing on the Pyasina river is described.
 Purpose: to show the current size, age, and demographic characteristics of the
 main commercial fish species of the Pyasina river.