Now showing items 21-40 of 4727

    • Pesticides of modern classes in water and bottom sediments of Veselovsky, Proletarsky and Krasnodar Reservoirs

      Valiullin, Vasil A.; Zinchuk, Olga A.; Karpushina, Yuliya E. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      Veselovsky, Proletarsky and Krasnodar Reservoirs are located in the area, extensively used for various agricultural purposes. This industry requires the use of means to protect cultivated plants from pests. When land is treated with pesticides, these substances can enter water bodies of fisheries importance through the air and soil, accumulate in bottom sediments and have a negative impact on the vital functions of hydrobionts. Using the method of high-performance liquid chromatography (HPLC), 20 active ingredients (AI) of pesticides of modern classes that are used in agriculture of the region and the half-life of which can exceed six months have been investigated. In preparation for chromatography, pesticides were extracted from the samples of water and bottom sediments with dichloromethane, followed by drying and purification of the extracts. It has been established that the concentrations of pesticide AIs in the aquatic living environment of the investigated reservoirs are more than an order of magnitude lower than the established maximum permissible concentrations (MPCs).
    • Stock assessment of the European anchovy and European sprat in the Russian waters of the Black Sea in 2022–2023

      Shlyakhov, Vladislav; Negoda, Sergey A.; Piatinskii, Mikhail; Shlyakhova, Olga V. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      The results of the stock assessments of the European anchovy and European sprat, exploited by the Russian Federation in the Black Sea exclusively or predominantly, are presented. Based on the results of production modeling in 2022, the biomass value of the “Azov Sea” anchovy stock unit was in the buffer zone, between the target and limit biological reference points (Btr=BMSY=123.3 thousand tons, Blim=61.6 thousand tons); the time of stock recovery to the target level is 4 years. The fishing mortality rate (annual fishing loss, F) in 2022 is estimated to be F2022=0.20, which is lower than the biological reference point (Ftr=0.23). The estimation based on the lampara net surveys is more favorable: spawning stock biomass (exploitable) SSB2022 exceeded Btr calculated using Ricker’s “stock–recruitment” relationship by 19 %. The Azov Sea stock of the European anchovy has been characterized as “showing the evidence for recovery under heavy exploitation; subjected to the environmental effects”. In the 2022/2023 fishing season, fishing operations on the Black Sea stock of the European anchovy were mostly absent due to the state-imposed limitation in the Northwestern Black Sea and the western waters along the Southern Coast of Crimea (SCC). The biomass of the “Black Sea” anchovy stock unit in 2022, based on the results of JABBA trend modeling in “catch-only” representation, has been estimated as B2022=22.5 thousand tons, which is 3 % lower than the target reference point Btr=BMSY=23.2 thousand tons. The ratio between the current fishing mortality and its biological reference point was F2022/FMSY=0.467, which is indicative of its low exploitation. The catch composition of the European sprat in 2022–2023 was characterized by the prevalence of the 2+ and 3+ age classes (71–87 % by abundance). Based on XSA, in 2022, the spawning stock biomass (exploitable biomass) SSB2022 was 67.2 thousand tons, the recruitment was 56 billion ind., and the fishing mortality was F2022=0.29. The spawning stock biomass was in the buffer zone between the limit and target biological reference points by the biomass (SSB2022/SSBtr=1.433, SSB2022/SSBtr=0.841), while the fishing mortality was considerably lower than its biological reference point (F/F0.1=0.479). In 2022, the current Black Sea stocks of anchovy and sprat were officially characterized as “declining, little exploited”, with the possibility for underestimation of their biomass.
    • Characterization of the zooplankton community of the western part of the Proletarsky Reservoir in the spring season of 2021–2022

      Шляхова, Наталия (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      The Proletarsky Reservoir located in the Kuma–Manych Depression is a water body that is highly important for the fisheries in the Southern Russia. Its western part is the most economically valuable, which necessitates the investigation of its zooplankton serving as a food source for the larvae and planktivorous fish. This work presents the results of investigation of the zooplankton community in this area during fish spawning campaign in the spring seasons of 2021–2022. In spring, the zooplankton was represented by 4 groups of organisms (30 species), which include rotifers, copepods, cladocerans, and meroplankton. Among them, the copepods were the most diverse, with the species of Cyclopoida suborder being the most prevalent. The rotifers were the most abundant, comprising 67 % of the total zooplankton abundance. The cladocerans comprised the major part of the zooplankton biomass; their share in the total biomass consistently remained at 79 %. The total biomass of the zooplankton exceeded 300 mg/m3, which is sufficient to provide the planktivorous fish species and their larvae with a food source.
    • Results of the rearing of zander Sander lucioperca (L.) and roach Rutilus rutilus (L.) juveniles in the hatcheries of the Krasnodar Territory in 2023

      Poroshina, E. A.; Polin, A. A.; Shevchenko, V. N.; Sergeeva, S. G. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      This work presents quantitative data collected in the course of zander and roach artificial reproduction in the hatcheries of the Krasnodar Territory in 2023. Based on the surveys, 4.68 t of roach and 17.5 t of zander entered the reservoirs of Yeysk Experimental Hatchery for spawning. For the first time during the long-term observations, young individuals of low reproductive quality prevailed in the roach spawning stock. During the downstream migration, roach juveniles were absent in catches, and zander juveniles occurred very sporadically, which indicates their increased loss during all stages of early ontogenesis. The data collected in Beysug Hatchery gives evidence of 2.484 t of roach and 2.557 t of zander entering its reservoirs for spawning. In June–July, during the downstream migration, 16.48 million ind. of roach juveniles, which weight ranged from 0.3 to 1.2 g, were recorded; for zander juveniles these values were 0.140 million ind. and 0.91–1.53 g. The downstream migration of juveniles continued in August. At the floodgate of East-Akhtarsk Hatchery, the monitoring of breeders recorded 0.457 t of roach and 0.088 t of zander. The breeders were of low reproductive quality. Based on quantitative evaluation, the reproduction yield in the East-Akhtarsk Hatchery reservoir was 153.4 million ind. of roach (weight ranging from 0.3 to 0.96 g) and 102.25 million ind. of zander (weight 1.28–2.07 g). The monitoring of breeders entering the limans of Chernoerkovsk Hatchery recorded 8.0 t of roach and 12.85 t of zander. Chernorkovsk Hatchery showed the highest results: 426.32 million ind. of roach juveniles (weight 0.3–0.9 g) and 218.16 million ind. of zander juveniles (weight 0.47–3.37 g). Analysis of the obtained data has shown that low reproductive efficiency of both roach and zander is indicative for almost all investigated reservoirs of the hatcheries.
    • Results of artificial reproduction of the starry sturgeon in the Azov–Don Region in 2021–2022

      Pavlyuk, A. A.; Sergeeva, S. G.; Gorbenko, E. V.; Vorobyeva, O. A.; Shevchenko, V. N. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      Over the course of the monitoring surveys conducted in 2021–2022, the specific features of the starry sturgeon reproduction have been investigated, which covered the span from the adaptation of breeders to the release of juveniles into a natural water body. The results of this study indicate that the starry sturgeon females from the broodstock have low reproduction capacity, as well as decreased embryo survival rates and larvae yield. The starry sturgeon juveniles reared in tanks were characterized by low growth rates, decreased feed conversion efficiency, and acceptable physiological status. It has been shown that rearing the starry sturgeon juveniles in tanks is less expedient than using a combined method.
    • Estimated contribution of the breeding facilities of the Azov Sea Basin into the recruitment of the natural populations of the sturgeon species

      Bugaev, Leonid A.; Nebesikhina, Natalya; Mirzoyan, Arsen V.; Vojkina, Anna (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      Over the course of long-term studies, the contribution of some sturgeon hatcheries into the population abundance of the sturgeon species in the Azov and Black Sea Basin has been investigated. For this purpose, the genotypes of the Russian sturgeon and starry sturgeon breeders from the hatchery broodstocks have been analyzed and compared with the sturgeon juveniles caught in the natural water bodies to identify their relation. It has been found out that the frequency of occurrence of the juveniles spawned by the breeders from the hatchery broodstocks does not correlate with the number of juveniles released by the corresponding breeding facility. The largest share of the investigated Russian sturgeon juveniles originated from the breeders from the Don Sturgeon Hatchery (77 %); the offspring of the breeders from the Temryuk Sturgeon Hatchery comprised 20 % of the total number, and 3 % of the juveniles originated from the Grivensk Sturgeon Hatchery. Out of the investigated starry sturgeon juveniles, the share of the offspring was 37 % for the Don Sturgeon Hatchery, 61 % for the Grivensk Sturgeon Hatchery, and 2 % for the Temryuk Sturgeon Hatchery.
    • Challenges in artificial reproduction of the sterlet sturgeon in the Azov–Don Region at the present time

      Gorbenko, E. V.; Vorobyeva, O. A.; Pavlyuk, A. A.; Sergeeva, S. G. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      The abundance of the sterlet population in the Don River is maintained by means of annual releases of its juveniles. For the reproduction, the breeders from the broodstock created in the Don Sturgeon Hatchery are used. Over 2019–2022, sturgeon hatcheries of the Azov-Don Branch of the FSBI “Glavrybvod” (Main Basin Department for Fisheries and Conservation of Aquatic Biological Resources) at the Don River downstream from Tsimlyansk Reservoir released 6.893 million sterlet juveniles exceeding 1.5 g in weight. Analysis of the data has shown that the efficiency of reproduction in this sturgeon species depends on the quality of the reared juveniles and the breeders involved in reproduction.
    • Physiological and biochemical status of the European anchovy Engraulis encrasicolus (Linnaeus, 1758) in the Azov and Black Sea Basin in 2020–2022

      Vojkina, Anna; Bugaev, Leonid A.; Negoda, Sergey A.; Kirichenko, Olga V.; Yurchenko, Kseniya A. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      The dynamics of lipid content in the body of anchovy (Engraulis encrasicolus) at various stages of its life cycle has been analyzed for the time range from 2020 to 2022. This article indicates that the content of constructive and energy-bearing substances in the anchovy body is discernibly dependent on the fish’s age: the lipid content in fingerlings is lower than in older individuals. Based on the analysis of the inter-seasonal dynamics of the lipid content in the anchovy body, it has been identified that the lowest lipid content is typical for this fish in April, and the highest lipid content is observed in October. The analysis of the inter-annual dynamics of the lipid content in the anchovy body at the end of its feeding period has shown that, for the last three years, there has been a trend towards a gradual increase in the content of lipids to 16–18 %.
    • Reproduction and conditions determining the generation yield in the Azov Sea stocks of the Black Sea–Caspian sprat (tyulka) in 1993–2022

      Nadolinskiy, Roman V.; Mirzoyan, Zinaida (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      Variability in the yield of the Azov Sea tyulka (Azov Sea stocks of the Black Sea–Caspian sprat) generations affected by the environmental changes in 1993–2022 has been estimated. Stock assessments of the ichthyoplankton have been conducted in the Azov Sea in June for more than 50 years. Evaluation of the fingerling abundance is carried out in the course of the surveys with lampara nets in August. During the survey period, considerable environmental changes attributable to natural and anthropogenic factors have been identified; they heavily influence the yield of the Azov Sea tyulka generations.
    • The use of a newly-designed purse seine for exploitation of the sparse aggregations of the Black Sea–Caspian sprat (tyulka) in the Azov Sea

      Stafikopulo, Aleksei; Andronov, V.A.; Vtyurina, N.V.; Gorbatyuk, Ya.I. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      This paper considers the issues of the Black Sea–Caspian sprat (tyulka) fishing in the Azov Sea, which stem from various factors preventing formation of its dense aggregations at present and, as a consequence, inhibiting its exploitation with purse seines. Purse seines traditionally used for the Black Sea–Caspian sprat fishing have been designed as multipurpose, which includes anchovy fishing in deep waters of the Black Sea, so they have considerable disadvantages for their application in the relatively shallow Azov Sea. When fishing operations are conducted on sparse aggregations of the Black Sea–Caspian sprat at shallow depths, the most crucial role is played by the seine length ensuring a large catch area. The current design of a purse seine does not allow for a considerable increase of the seine length because, in such seines, their length is directly dependent on their height. Implementation of midwater trawls for the Black Sea–Caspian sprat fishing occurring since 2013 has not improved the situation—all vessels engaged in it switched over to using trawls, but the catch values still tend to decrease. Meanwhile, the issue of reducing the by-catch of non-target species, mainly sturgeons which abundance in the Azov Sea remains on a long-term decline, in the midwater trawls becomes more and more pressing. Coastal fishing of the Black Sea–Caspian sprat with pound nets also shows the decrease in catch volumes. Increasing the efficiency of the Black Sea–Caspian sprat fishing off the board of fishing vessels should involve the implementation of selective and environmentally sound purse-type fishing gear for exploitation of its sparse aggregations in the Azov Sea that could be operated using current technical equipment on the vessels of the small-sized fishing seiner type with 165 kW capacity (Black Sea Medium Seiner 225). A new design of a fishing gear combining the elements of purse and beach seines has been developed. This fishing gear is comprised of a long, low-height and light-weight tow wing that, during hauling, should drive the fish to a shore wing where pursing of the seine occurs. The proposed purse seine design featuring a lengthened wing with the length of 1500 m along its headrope will allow for the 9-time increase in catch area with the same netting consumption as in a standard purse seine. Setting and hauling of such a seine can be conducted using the technical equipment already installed on the vessel.
    • Results of the monitoring of the Azov turbot (Psetta maeotica torosus Pallas) fishing operations in the first half of 2023

      Aleksandrova, U. N. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      This article summarizes the data collected during the fishing of the Azov turbot in the five-kilometer coastal area of the Azov Sea in the first half of 2023. At present, the environmental conditions here are favorable for turbot reproduction and development. Turbot stock reached 2.9 thousand tons, which allowed for its successful exploitation.
    • Results of the monitoring surveys of the so-iuy mullet (Planiliza haematocheilus) fishing operations in the Azov Sea in the first half of 2023

      Shelestyukova, A. A. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      This article summarizes the data collected during the monitoring surveys of the so-iuy mullet fishing operations in the five-kilometer coastal area of the Azov Sea in the first half of 2023. The environmental conditions and increased salinity in the Azov Sea were favorable for so-iuy mullet reproduction and development in 2023. At present, the trend for the restoration of so-iuy mullet stocks made it possible to start a gradual restitution of the exploitation of this species.
    • DNA identification of the fish belonging to the Gobiidae family from the Azov Sea

      Nebesikhina, N.A.; Bugaev, L.A.; Alimova, A.Sh.; Gaydamachenko, V.N.; Meshchankina, V.S. (2023)
      Труды АзНИИРХ / Proceedings of AzNIIRKH
      This article presents the results of DNA identification of the fish belonging to the Gobiidae family, with the COI and CytB gene fragments used as a molecular marker. The calculated average intra- and inter-specific genetic distances differed by more than an order of magnitude. Molecular markers of the COI and CytB genes can be effectively used for the identification of the Gobiidae fish species.
    • Release of juvenile sturgeons in the Azov–Kuban region by sturgeon hatcheries of the Federal Agency for Fishery in 2016–2022

      Polin, A.A.; Shevchenko, V.N. (2023)
      Aquatic Bioresources & Environment
      By the end of the 20th and the beginning of the 21st century, artificial reproduction had taken up a key role in the sturgeon stock recruitment in the natural water bodies of the Azov–Kuban region. The major part of artificial reproduction of sturgeon species is conducted in the fish hatcheries of the Azov–Kuban region under the authority of the Federal Agency for Fishery (Rosrybolovstvo). The aim of this study was to analyze the volumes of rearing and release of juvenile sturgeons into water bodies of fisheries importance in the Azov–Kuban region by fish hatcheries subordinate to the Federal Agency for Fishery. This article is based on the data recordings of the Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”) for the time range from 2016 through 2022. The data on 4 sturgeon hatcheries (Adygea, Achuevo, Grivensk, and Temryuk) are presented and analyzed. Results. An increase in the total number of juveniles of sturgeon species released into the natural habitat has been revealed. The highest values were recorded in 2021–2022. There has also been a disproportion in the number of released juveniles belonging to different species. Each year, sterlet Acipenser ruthenus accounted for a large share of released juveniles, for which the percentage ranged from 47.6 % in 2018 to 64.4 % in 2022. In recent years, the volumes of rearing and releasing the juveniles of this species have been increasing both quantitatively and in percentage terms. This fact can be explained by the earlier maturation of sterlet breeders, shorter intervals between repeated spawning, and the resultant larger number of “active” breeders of this species in the hatcheries. From 2019 through 2022, the share of the juveniles of sturgeon species released by the hatcheries of the Federal Agency for Fishery into the Protoka River, as compared to the Kuban River, increased from 55.0±0.10 % in 2016–2018 to 68.9±0.44 % (2019–2022). It resulted from the increase in the number of the sturgeon juveniles released into this water body, and not from a redistribution of release volumes between the Kuban and Protoka Rivers. In general, the artificial reproduction of sturgeon species by the fish hatcheries of the Federal Agency for Fishery in the Azov–Kuban Basin has shown a positive dynamics. However, it has also been found necessary to increase the scale of artificial reproduction of the most commercially valuable anadromous species: Russian sturgeon Acipenser gueldenstaedtii and stellate sturgeon Acipenser stellatus.
    • Artificial reproduction of semi-anadromous fish species under different development scenarios of hydrological situation in the Azov Sea

      Mirzoyan, A.V.; Belousov, V.N.; Shevchenko, V.N.; Polin, A.A.; Rybalchenko, A.D.; Poroshina, E.A. (2023)
      Aquatic Bioresources & Environment
      Semi-anadromous fish species of the Azov Sea were the primary fishing targets before the regulation of the flow of the Don and Kuban Rivers, after the anthropogenic transformation of which artificial reproduction became the main source of recruitment for the populations of these species of aquatic biological resources. Unprecedented climate-induced reduction in the volume of freshwater runoff in 2006–2023 aggravated the deterioration of the conditions for reproduction of anadromous fish species in the aquatic areas associated with fish feeding and rearing facilities and contributed to the decline of their feeding conditions in the sea resulting from a sharp increase in salinity, which led to a reduction in their population abundance. Relevance. In the context of a record reduction in freshwater runoff and increasing salinity of the Azov Sea, the Azov Sea ichthyocenosis undergoes a fundamental restructuring, which requires making a forecast of the possible changes in the habitat of semi-anadromous fish species, as well as evaluating the prospects for artificial reproduction of zander, roach and bream for their preservation in new conditions, which, in turn, serves as the aim of this work. To predict possible changes in the hydrological regime of the Azov Sea, the expert evaluation method has been used. The expert assessment of possible scenarios of the impact exerted by the modern climate change on the habitat of the aquatic biological resources in the Azov Sea has been done with the regard to the provisions of the Climate Doctrine of the Russian Federation. Under all predicted scenarios for the period up to 2030, the salinity of the Azov Sea will exceed the values optimal for the juveniles and mature individuals of semi-anadromous fish species. Preservation of biologically valuable populations of zander and roach is possible with the continuous operation of hatcheries (spawning and rearing facilities), both in limans and on floodplain. To preserve the population and increase the stock of bream, it is necessary to restore artificial reproduction of this species. In the medium term (until 2030), only roach has a prospect for the sufficient recovery of its stocks, which could happen under the favorable hydrological scenario involving the water content increase in the basin. In all other cases, bream, zander and roach will not be in position to considerably increase their abundance.
    • Morphological characteristics and biological features of Smith's barb Puntioplites proctozystron (Bleeker, 1865) in the Mekong River Delta

      Karpova, Evgeniia; Iskiv, Aleksandra; Shavriev, Dmitry; Dinh Cu, Nguyen; Ba Hai, Truong (2023)
      Aquatic Bioresources & Environment
      Fisheries in the Mekong River are characterized by high pressure and extremely low selectivity towards fishing targets, which greatly complicates the conservation and possible restoration of the region's biodiversity. Relevance. Knowledge of fish population structure and biology is essential for fishery management and rational use of resources; however, the fisheries of the region are predominantly artisanal, for which the information on catches is scarce. This work is aimed at a study of the morphological characteristics of Smith's barb Puntioplites proctozystron (Bleeker, 1865) and the distribution of its quantitative parameters. The data have been collected from the bottom trawl catches in the Mekong River Delta that were conducted using a beam trawl in the low water and flood periods of 2018–2022. The average abundance and biomass of this species in fresh waters were 8.3±20.8 ind./ha and 114.7±229.4 g/ha, and in the estuary they were 0.6±2.7 ind./ha and 12.1±63.5 g/ha. These quantitative parameters for Smith's barb in the relatively shallow and low-flow Hau River and its estuarine channels were statistically significantly higher than in the rest of the delta estuary system (8.5±22.2 ind./ha and 110.7±248.7 g/ha as compared to 1.4±6.5 ind./ha and 25.0±90.1 g/ha). Examination of morphological characteristics showed a very low variability of traits in mature individuals; the coefficient of variation was less than 10 %. The obtained results indicate the absence of sexual dimorphism and different morphotypes in the population, provide the ground for minimum landing size recommendations, and can serve as a foundation for the further population research of this species.
    • Scientific, Technical and Economic Committee for Fisheries (STECF) - Evaluation of fishing effort and catch regime for demersal fisheries in the western Mediterranean Sea (Part XI) (STECF-23-11)

      Bitetto, Isabella; Certain, Gregoire; Döring, Ralf; Garriga Panisello, Mariona; Gourguet, Sophie; Grati, Fabio; Lehuta, Sigrid; Mahevas, Stephanie; Merzéréaud, Mathieu; Murenu, Matteo; et al. (Publications Office of the European Union,, 2023)
      Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines. This report is the 11th of a suite of STECF EWG reports dedicated to the evaluation of the implementation of the Western Mediterranean Sea Multi-Annual management Plan (hereafter, MAP), following EWG reports 18-09, 18-13, 19-01, 19-14, 20-13, 21-01, 21- 13, 22-01, 22- 11 and 23-01. The group was requested to update the graphical representation of fishing effort time series evolution by MS, GSA, vessel length and gear with the latest data obtained from the FDI datacall (TOR 1). Together with the fishing effort time series the group was requested to update the F-E analysis by stock and gear using the outputs from STECF EWG 23-09 (TOR 2). The group was also requested to collect qualitative information on the fuel related situation to potentially estimate cost changes in 2022-2023 (TOR2). Finally, the group was requested to implement mixed fisheries bio-economic models to run a number of different scenarios up to 2030 to test a combination of measures taking into account all the effort reductions, closure areas and maximum catch limits (MCLs) introduced in the western Mediterranean MAP since 2020 (TOR 3-4). Within the scenarios a combination of effort reductions and MSLs were tested, together with the introduction of spatio-temporal closures and selectivity restrictions to obtain compensation mechanisms by MSs. A total number of 13 scenarios were requested, 6 of which were considered priority scenarios. For TOR 1 time series of fishing effort in fishing days, days at sea, hours at sea, GT x fishing days, and kW x fishing days by Country (Spain, France, Italy), EMU (1 and 2), GSA (1, 5, 6, 7, 8, 9, 10, 11), gear (OTB, OTT, GNS, GTR, LLS, other), and fleet segment (<12m, 12-18m, 18-24m, >24m) were produced. Graphs for fishing days are reported in the report while the rest of the data are submitted in Annex I as an Excel table. The comparison of fishing days for trawlers (OTB, OTM, OTT, PTB, PTM and TBB as per EU regulation 2019/2236) declared in the FDI official datacall and reported in the 2020, 2021, 2022 and 2023 regulations were reported this year as well. Across fleet segments, the fishing effort from the regulation is greater, for most segments, than that estimated through the FDI database. This could be due to the regulation values being calculated considering the maximum fishing days possible for the year and also difficult to estimate the possible transfer among fleet segments. An additional analysis (section 2.3) was added to provide a broad context of the state and evolution of the fishery in EMU-1 (encompassing GSAs 1,5,6,7), through the detailed examination of weights, values and prices landed by stocks and fleet segments using the FDI data submitted to the group. It was observed that during the implementation of the MAP, all fleet segments have not evolved in the same way. If all demersal trawlers seem to face a substantial contraction of their landed values, deep-water trawlers are increasing their landed value, most likely thanks to an increased ARA price. Still, for many other fleets, the transition rates before and during the plan remains similar. For TOR 2 the F-E analysis was updated and as in previous years a linear relationship consistent across GSAs and stocks was not found for any gear. Those stocks were there seem to be a linear relationship, such as HKE, ARA, DPS (except for DPS 1), it was shown that there is an effect of the GSA level which should be accounted for in future modelling exercises potentially using mixed effect models. Concerning fuel prices the group noted that marine fuel prices are significantly influenced by global oil prices which are driven by factors like international agreements, supply disruptions, or changes in demand. Geopolitical tensions and conflicts, sanctions or embargoes on certain countries can affect the availability and cost of marine fuels. Technology and efficiency improvements can impact fuel efficiency and investments in energy-efficient vessels and propulsion systems can lead to cost savings. Also, environmental concerns, such as reducing carbon emissions and promoting sustainable fishing practices, are affecting fuel usage and prices. It's also important to consider that marine fuel prices can vary significantly by region and port, depending on local factors, taxes, subsidies, transportation costs and regulations. In particular, governments may provide subsidies or financial incentives to the fishing industry to mitigate the impact of high fuel prices or promote environmentally friendly practices. Within the group the EUMOFA and AER data are used to parameterize the models. On these data the group highlighted two issues for a correct interpretation of the model results: 1. The financial situation which the bio-economic models present for the year 2022 and beyond depend a lot on the assumptions regarding the development of fuel prices but include no mitigation measures for the fishing companies (like de minimis payments to cover parts of the increase in fuel costs 2022). STECF plenary (22-03) agreed not to include those support payments to allow distinguishing between the impacts of the MAP from external economic shocks. 2. STECF PLEN (22-03) observed that the nowcast for 2023 (that are now used as input data for the models) should be interpreted with caution due to the fact that the development in the second half of the year (energy and fish prices, inflation, interest rates etc.) is unknown and highly uncertain. FOR TOR 3 results for EMU 1 are obtained from the IAM and the ISIS-Fish models: from the IAM model only scenarios adjusting trawler fishing effort to reach Fmsy of Hake (i.e. scenarios A and D) foresee exploitation levels in line with the objectives of the plan, i.e. all stocks at Fmsy in 2025. With the two other simulated scenarios, in which only maximum catch limit on ARA was applied, with or without selectivity measures on deep water trawls, i.e. scenarios Status Quo and L, respectively, the stocks of Hake in GSA1567, red mullet in GSA1, red mullet in GSA6, Nephrops in GSA 6, and Blue and red shrimp in GSA 5 do not reach the objective of Fmsy in 2025. Scenarios allowing to reach Fmsy for all stocks foresee some significant negative socio-economic impacts for French and Spanish trawlers in the short and medium term, with a reduction in their Gross Value Added, Gross Profit, employment in terms of Full Time Equivalent (FTE), and average wages. From the ISIS-Fish model results showed that the SQ scenario did not achieve the objective of the plan regarding HKE, as fishing mortality stays way above Fmsy and the SSB below Blim. The four other scenarios, A, B, C and E, on the contrary succeeded in reaching Fmsy at the latest in 2028 and Hake SSB was above Blim but below Bpa starting in 2029. The determinant factor was the adjustment of effort to reach Fmsy, which implied reductions in effort level of more than 60% compared to 2022 FDI values. Economic indicators for ISIS- Fish could not be reported. In EMU 2 results are obtained from models BEMTOOL and SMART: from the BEMTOOL model for ARS, MUT9 and DPS the Fmsy level is reached by 2025 for all the scenarios explored. For DPS an increase in F is expected in 2024 for scenario L, due to the reallocation of the effort induced by the catch limit, but in 2025 the value is below Fmsy. For HKE and NEP9 only scenarios A, C and D (which are forced to reach Fmsy by 2025) allow to reach Fmsy in 2025, while SQ and L have F well above the reference point. It should be noticed that the change in selectivity implemented in scenario L show a slight improvement in respect to the SQ scenario for HKE, but it does not allow to reach Fmsy in 2025. As a general consideration, the scenarios most impacting on the effort highlight the risk of underutilization of the stocks that currently already are close or in line with the reference point. Results for the stock of MUT 10 and ARA in 9-10-11 should be taken with caution as no analytical assessment was available for these two stocks in the last two years. The results of the economic indicators showed that in the short term for all the alternative scenarios is expected a decrease, which generally is followed by an increase in the medium-long term. For the SMART model for four of the five stocks (ARS, DPS, HKE, and MUT) the scenarios associated with the best effect on the stock are A, C, D, E and L. For NEP, the situation seems to be much more complex and only scenario A allows you to get close to the BPA (Precautionary Biomass Level) value. However, all the simulated scenarios show a substantial reduction in Gross profit margin. Results suggest that in EMU 1 and 2 Fmsy in 2025 is reached for all stocks only when effort is decreased as much as 60% to 85% depending on the fleet segment observed, with bigger segments suffering a higher reduction. Scenarios accounting for an MCL on ARA and ARS do not allow to reach Fmsy for all stocks including HKE. In EMU 2, the ARS, MUT and DPS stocks are already close or at Fmsy becoming underutilized due to the reductions to bring HKE and NEP at Fmsy.
    • Scientific, Technical and Economic Committee for Fisheries (STECF) - Stock assessments in the Western Mediterranean Sea (STECF 23-09)

      Ligas, Alessandro; Mannini, Alessandro; Certain, Gregoire; Costantini, Ilaria; Couve, Pablo; García, Encarni; Garriga Panisello, Mariona; Guijarro, Beatriz; Kupschus, Sven; Mantopoulou Palouka, Danai; et al. (Publications Office of the European Union, 2023)
      Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines This report documents the outcomes of STECF Expert Working Group 23-09: 2023 stock assessments of demersal stocks in the Western Mediterranean Sea from the meeting held in hybrid mode from 4th to 10th September 2023. A total of 20 fish stocks considered. Nine stocks were evaluated by means of a statistical catch at age (SCAA) model (a4a). Due to the lack of survey information in 2022, five stocks were evaluated through a catch weight projection and short-term forecast. The methodological approach is described in the last part of this Executive Summary, and in the Report. In 2022, index- based advice was given for three stocks (ARA8-9-10-11 and NEP11 on two years basis while for MUT 10 just for one year), and they were re-evaluated by EWG 23-09. The advice for ARA8-9-10-11 and NEP11 have been confirmed while for MUT 10 the missing index information led the group to consider downgrading the advice from an index-based one to a catch only advice approach (ICES Category 5). Two stocks for which the index-based advice provided in 2021 (2 years advice) have been evaluated again looking for a plausible fully analytical assessment. None of the model setting tried was able to provide acceptable results, therefore a biomass index-based advice is given again. The content of the report gives the STECF terms of reference; the basis of the evaluations; assessments, reference point calculations; summaries of state of stock and advised catch or F based on either the MSY approach for assessed stocks and category 3 and 5 based advice for those without assessments. The report contains the full stock assessment reports, the exploration of assessments and category 3 and 5 evaluations for the remaining stocks. The report also contains the STECF observations and conclusions on the assessment report. These conclusions come from the STECF mini plenary meeting October 2023.
    • Marine Geohazards: Safeguarding society and the Blue Economy from a hidden threat

      Kopp, Heidrun; Chiocci, Francesco Latino; Berndt, Christian; Çağatay, Namık; Ferreira, Teresa; Fortes, Juana; Gràcia, Eulàlia; González Vega, Alba; Kopf, Achim; Sørensen, Mathilde B.; et al. (European Marine Board, 2021)
      Marine geohazards pose a significant threat to the European coastal population and to the development of the Blue Economy. This Position Paper discusses the type, distribution and impact of marine geohazards on the European coastal regions and the Blue Economy, as well as what and how novel scientific approaches may broaden our understanding of their trigger mechanisms and drive a risk-mitigating European policy.
    • Addressing underwater noise in Europe: Current state of knowledge and future priorities

      Thomsen, Frank; Mendes, Sónia; Bertucci, Frédéric; Breitzke, Monika; Ciappi, Elena; Cresci, Alessandro; Debusschere, Elisabeth; Ducatel, Cecile; Folegot, Thomas; Juretzek, Carina; et al. (European Marine Board, 2021)
      The Ocean presents a cacophony of sounds originating from natural as well as anthropogenic sources. Marine organisms heavily rely on sound to communicate and understand the world around them, and are therefore potentially impacted by anthropogenic sound. However, in developing our Blue Economy and in advancing our knowledge of marine environments and ecosystems, anthropogenic noise is sometimes unavoidable. Understanding the potential effects of anthropogenic noise is therefore integral to addressing this conflict, as it is needed to develop proportionate mitigation strategies and effective regulation. Next to providing an overview of our current knowledge about underwater noise, this publication highlights the priority areas for further research addressing the remaining knowledge gaps about the effects of anthropogenic noise. Furthermore, it points out the relevant actions needed to take in order to ensure ecosystem-based and precautionary legislation.