Maximum Catch Research Articles

Climate change undermines seafood micronutrient supply from wild-capture fisheries in Southeast Asia and Pacific Island countries

Marine ecosystem functions are affected by climate change impacts such as ocean warming, deoxygenation and acidification. These impacts drive changes in distributions and body size of fish species and directly affect fisheries. Wild-capture fisheries are crucial for providing nutrients, livelihoods, and employment in tropical Southeast Asia and Pacific Island countries, where coastal communities are highly vulnerable to climate change. We examined the impacts of climate change on fish stocks and nutrient availability of seven key micronutrients (calcium, Omega-3 fatty acids, iodine, iron, vitamin A, vitamin B12 and zinc) in Southeast Asia, Pacific Islands, and Oceania (Australia and New Zealand). We combined micronutrient demands by local human populations with Sea Around Us reconstructed catch time series and catch projections from a dynamic bioclimate envelope model for the 21st century. The model predicted a decline in the Maximum Catch Potential (MCP) within Exclusive Economic Zones for Oceania, Pacific Islands, and Southeast Asian countries. Under the ‘strong mitigation’ scenario, catch potential reductions ranged from a decline of 54–66 % in Oceania, 58–92 % in Pacific Islands, and 65–86 % in Southeast Asia by the mid to the end of the 21st century relative to the historical period, respectively. Under the ‘no-mitigation’ climate scenario, reductions were more severe, with a decline of 55–70 % in Oceania, 66–92 % in Pacific Islands, and 70–86 % in Southeast Asia for the same time periods. Our findings indicate that Australia and New Zealand are unlikely to meet the recommended nutrient intake demand for most micronutrients through their fisheries (not considering trade or aquaculture production), except for iodine and vitamin B12. Pacific Island countries will likely follow the same pattern while Southeast Asia is expected to face worsening deficits, except for iodine and vitamin B12. This study highlights the importance of incorporating nutritional considerations of seafood into national food, trade and economic policies.

Seasonal effects on blue swimming crab catch per unit effort (CPUE) in Tiworo Strait, Southeast Sulawesi, Indonesia

Abstract Blue swimming crab (BSC) resources are fisheries commodities that have important economic value, so their utilization needs to be carried out sustainably. Understanding crab fishing season patterns is very important in efforts to improve the efficiency and effectiveness of crab fishing industry. This study aimed to analyze the abundance and catch per unit effort (CPUE) of blue swimming crab based on season in the the Tiworo Strait, Southeast Sulawesi, Indonesia. BSC sampling was conducted monthly from October 2022 to March 2023 (west season) and April to September 2023 (east season). The results showed that the maximum catch occurred during the east to west transition season, amounting to 1,668.50 kg, while the lowest catch was 376.70 kg with a total of 1,032 trips. The maximum catch in the west season was 1,402.10 kg, while the lowest was 666.50 kg with a total of 1,265 trips. The highest CPUE value was observed in July at 7.92 kg/trip, while the lowest CPUE occurred in April at 2.18 kg/trip. Differences in crab catches and number of trips in each season may be influenced by environmental conditions that occur in that season as well the location of the fishing ground.

Analysis of the Status of Sustainable Utilization and Management of Flyfish (Decapterus russelli) Resources in Pasongsongan Waters, Sumenep Regency using the Walter-Hilborn Model

Flyfish (Decapterus russelli) is a small pelagic fish with a fairly high economic value. Flying fish are the fish with the highest production landed at the Pasongsongan Beach Fisheries Port, Sumenep Regency. In recent years, the production of flying fish in Pasongsongan has continued to decline, excessive fishing activities and an increase in the number of fleets are feared to interfere with the sustainability of flying fish resources. Therefore, sustainable management of flyfish resources needs to be carried out, the purpose of this study is to find out the sustainable potential of flyfish resources, to know the number of catches allowed, and to know the status of the utilization of flyfish resources in Pasongsongan waters. The methods used in this study are quantitative and qualitative methods. The analysis used is a surplus production approach using 3 models, namely the Schaefer model, the Fox model and the Walter-Hilborn model. The results of the analysis using the Walter Hilborn model are a surplus production model that is suitable for use with a maximum catch value (Ymsy) of 2,255 tons and a permissible catch (JTB) of 1,804 tons, the utilization rate of flying fish landed in PPP Pasongsongan is 87% with the utilization status in the Fully Exploited category, where in this condition illustrates that the stock of resources has been exploited by 75-100%. An increase in the number of fishing efforts is not recommended even though the number of catches can still increase because it will interfere with the sustainability of fish resources.

Біологічна характеристика білого (Hypophthalmichthys molitrix Valenciennes, 1844), строкатого (Hypophthalmichthys nobilis Richardson, 1845) та гібрида товстолобиків (Hypophthalmichthys sp.) як обʼєктів випасної аквакультури в Кременчуцькому водосховищі

Purpose: Determination and analysis of parameters, which characterize the biological and fishery aspects of the formation and exploitation of the commercial stock of silver and bighead carps of the Kremenchuk Reservoir. Methodology. As primary materials, the results of field studies at the Kremenchuk Reservoir carried out in 2019-21 and 2023 have been used. Data collection and processing was carried out in accordance with generally accepted methods. Ichthyological material was collected from catches of commercial fishing nets with mesh sizes a=38-140 mm; in total, during the study period, catches of 2,254 fishing nets were examined, of which 652 individuals of silver and bighead carps as well as their hybrids were analyzed.. Predicted survival rate was assessed based on the annual natural mortality rate, which was determined based on the the Bertalanffy equation parameters. Statistical data processing was carried in MS Excel. Findings. In recent years, the basis of the commercial catches of silver, bighead carps and their hybrids in the Kremenchuk Reservoir was composed of age-7-10 fish, which was due to their predominant catch due to specialized fishing with nets with mesh sizes of a=100-140 mm, which accounted for up to 96.7% of the total catch of these species; the share of native species in the catches of these nets did not exceed 10%. The average annual absolute linear growth of these species in modal age groups was 6.0...9.6 cm, relative - 8.7...14.5%; the weight gains were 1416...3829 g and 28.1...43.5%, respectively, which indicated satisfactory grazing conditions in the Kremenchuk reservoir. The parameters of the Bertalanffy equation, which characterize the growth rate of silver, bighead carps and their hybrids in the Kremenchuk Reservoir, were: K = 1.08 (year-1), L∞ = 115.7 (cm) to = 0.17 (years). Based on the calculated natural mortality rates and 30% removal starting from age-5 fish, the fish return rate from stocking age-1+ fish into the Kremenchuk Reservoir is 10.2%. The peak culmination of ichthyomass of silver, bighead carps and their hybrids falls on age-4-6 fish; the optimal legal length of 55 cm allows ensuring the catch rates of 751 kg per 1,000 stocked age-1+ juveniles. Originality. Original data on the current state of commercial stocks of the main objects of pasture aquaculture in the Kremenchuk Reservoir were obtained from the point of view of the theoretical foundations of the formation and exploitation of their commercial stock. New methodical approaches to the assessment of fish return rate are proposed, as the main criterion for the effectiveness of measures for the artificial reproduction of ichthyofauna. Practical value. It has been established that the conditions for the formation of the commercial stock of the Kremenchuk Reservoir can be considered as satisfactory, i.e. the main limiting factor limiting the growth of their catches is the insufficient stocking volume. The obtained actual coefficients, which characterize the survival of fish seeds, can be used to forecast the volume of stocking and catch of silver, bighead carps and their hybrids. The shortcomings of the organization of modern fishery from the point of view of ensuring the maximum catch per recruitment unit have been established. The advisability of increasing the legal length for silver, bighead carps and their hybrids to 55 cm has been confirmed. Key words: Kremenchuk reservoir, pasture aquaculture, silver carp, bighead carp, organization of fishery.

The impact of ocean warming on selected commercial fisheries in New Zealand

AbstractWarming oceans affect the growth, reproduction and location of fish species. Using a bioeconomic framework, we estimate the relationship between sea surface temperature (SST) and the catch of de facto open‐access commercial fisheries of flatfish, trevally and jack mackerel in New Zealand. Assuming either a logarithmic or quadratic relationship between the SST and the carrying capacity of the fish stock, we consider three fishing methods (bottom trawl, set net and midwater trawl) and two measures of effort (count and duration). We show that ocean warming results in an increase in catch for all species if we assume a logarithmic relationship, with the highest marginal product of SST () for jack mackerel caught using midwater trawl. The highest marginal revenue product (computed by the MPSST, current price and fished area) is found for flatfish caught by set net. However, when assuming a quadratic relationship, there is a threshold above which catch starts to decrease, with the maximum catch of species ranging between 10 and 12.2°C. These results also vary spatially, with higher values of MPSST observed in areas closer to the South Pole. Our findings are relevant for any review of fisheries management systems in response to ocean warming.

Investigating insect catch metrics from a large Austrian museum

Insects can damage museum collections. Heritage organisations are increasingly alert to such risk, so have moved towards integrated pest management which sees monitoring as important to conservation strategies. Museum insects are usually monitored using sticky traps, although the records these provide are not always easy to interpret or analyse, so scoring methods, pest occurrence indices and zone systems have been used to use the observations to manage pests. A six-year trapping programme at almost 700 sites (i.e. traps) across six floors of a large museum in Austria provided a total catch of ∼30 000 arthropods. Catch rate (catch per trap) was higher on lower floors although there was a substantial year-to-year variation. In addition to blunder traps, a proportion using pheromones as an attractant were effective at catching T. bisselliella. The pheromone is not attractive to silverfish (Zygentoma) yet the shy insects appear to take cover in the pheromone traps. In contrast Attagenus spp. were caught at equal rates on both pheromone and blunder traps. The study examined what factors influence the catch of insects in traps. The overall catch in a room is proportional to the number of traps set out. Catch increases with the size of the room, but this may arise because the number of traps is also related to room size. More specifically catch seems proportional to square root of room area, suggesting it relates to its perimeter. Infestations are revealed by high catch rate, maximum catches on a set of traps and the proportion of traps that are active in catching insects. The study aims to assess which parameters that might assist in identifying infested locations in museums.

MATHEMATICAL MODELING OF FISH RESOURCES ASSESSMENT

In the field of fisheries, one of the key tasks is to determine the total and commercial stocks of fish resources in a water body, as well as to establish the maximum allowable catch of fish to maintain the sustainability of the ecosystem. Mathematical models play an important role in this process, providing effective resource management and predicting fish population dynamics, which ensures the sustainable development of fisheries and the protection of aquatic ecosystems from depletion. The aim of this study is to develop a new mathematical model for assessing changes in fish resource stocks using the cohort method. The work proposes an alternative approach to calculating changes in fish resource stocks based on statistical theory. The model developed in this work represents a new approach to calculating fish resources for practical application, which can be useful for fisheries enterprises and government bodies involved in fish resource management. The advantage of this work lies in the development of a mathematical model based solely on known statistical data and data obtained from fisheries laboratories in the Republic of Kazakhstan. Modern statistical methods were applied to solve the mathematical model, which allow for the identification of unknown factors affecting the dynamics of fish populations, thereby increasing the accuracy of forecasts and the efficiency of resource management.

Структурні показники та динаміка промислових уловів риб дніпровських водосховищ

Purpose: to establish and analyze the dynamics of the species composition and amounts of commercial fish catches over the past 10 years in the context of assessing the overall efficiency of the fishery exploitation of Dnieper reservoirs. Methodology. As primary materials, data from official commercial fishery statistics and the results of field monitoring studies carried out by the Institute of Fisheries of the National Academy of Sciences on Dnieper reservoirs in the period of 2012‒2022 were used. The intensity of commercial fish harvest was assessed by the annual fishing mortality rate, which was defined as the difference between the total and natural mortality. The total mortality rate was determined graphically by the natural logarithms of the number of age groups in catches; natural mortality — based on the parameters of the von Bertalanffy equation. Statistical data processing was carried out in MS Excel. Findings. The dynamics of commercial catches in the cascade of Dnieper reservoirs in the last 10 years has been characterized by instability with a minimum of 8.9 thousand tons in 2013 and a maximum of 14.0 thousand tons in 2019. The majority of commercial catches was Prussian carp (28.2% of the total catch), common bream (21.1%), roach (20.5%) and silver bream (8.3%). The catch dynamics of all limited species had the same features — a growth in the period 2014‒2016, stabilization until 2019 and a further decrease, which was due to the determining influence of organizational factors. The distribution of fishing pressure by the objects of fishing does not fully correspond to the quantitative parameters of their ichthyomass; the average (2019‒2021) coefficients of annual fishing mortality were: pikeperch — 32.0%, common bream — 22.8%, roach — 24.2%, silver bream — 22.7%, Prussian carp — 19.0%. The maximum catches per unit effort of the gill net in the studied period were recorded for the Kamianske reservoir (348.9±73.4 kg), the lowest (152.0±44.5 kg) — for the Kaniv reservoir. The average fish catch per one gill net per cascade was 245.1±36.3 kg; a trend towards its growth during 2012‒2021 was observed. Originality. Original data on the modern dynamics of the amount and structure of commercial fish catches as a component of scientific support for fisheries exploitation of the Dnieper reservoirs were obtained. Practical value. It has been found that the fluctuations of fish catches in Dnieper reservoirs are largely determined by the influence of external (organizational) factors, which makes it possible to effectively manage the use of fish stocks. It is shown that for some species (in particular, pikeperch), the intensity of fishery exploitation exceeds the optimum, for others (Prussian carp, Black Sea sprat), on the contrary, an increase in the fishing pressure is possible.

Advancing Integrated Pest Management: Utilizing Pheromone Traps for Population Monitoring of Plutella xylostella in Cole Crops

Plutella xylostella, commonly known as the diamondback moth poses significant challenges to Cole crops, impacting their growth and ultimately affecting yields. Its rapid reproduction coupled with its ability for developing pesticide resistance has elevated the diamondback moth to a critical concern for farmers and agricultural systems worldwide. The adult population of Diamondback moth was thus monitored during two cropping seasons (Kharif and Rabi season) at three locations viz., Vegetable Experimental Field, Faculty of Horticulture, SKUAST-K, Shalimar, Urban Technology Park, SKUAST-K, Habbak and Ichgam village in district Budgam using two different Plutella xylostella synthetic sex lures (SKUAST-K and Chipku lures). During Kharif season, the adult diamondback population was monitored from 18th to 28th SW with a maximum trap catch in the last week of June (26th SW) at Shalimar; whereas, both in Budgam and Habbak, the highest trap catch was in first week of June (23rd SW). However, in Rabi season, the adult population was monitored from 34th to 44th SW; the highest adult trap catch was in third week of September (38th SW) at Shalimar, though, in Budgam and Habbak, the moth catch peaked to maximum collection in first and second week of October (40th and 41st SW), respectively. During both the seasons and at all the locations, SKUAST-K lure proved more efficacious than Chipku lure. Besides, simple correlation analysis revealed that maximum temperature had positive and non-significant correlation with adult moth catches; conversely, the rainfall and relative humidity was negatively correlated and non-significant with P. xylostella adult trap catches throughout both observed seasons.

Analisis Hasil Tangkapan Udang Brown (Metapenaeus ensis) di Pelabuhan Perikanan Kuala Pembuang

This study aims to determine the results of Catch Per Unit Effort (CPUE), Maximum Sustainable Yield (MSY) and the utilization rate of brown shrimp (Metapenaeus ensis) at the Kuala Pemburan Fishing Port for the last 5 years (2017-2021). The basic method used in this study is a quantitative descriptive method derived from primary and secondary data. Data collection techniques were interviews and primary data collection in the form of shrimp production data at the Kuala Pemburan Fishing Port. Data analysis methods are CPUE, MSY and utilization rate analysis. The results of the study show that the CPUE value has fluctuated from 2017-2021. The highest CPUE value was in 2020 which was 37.76 kg/trip and the lowest was in 2017 which was 8.36 kg/trip. The high and low CPUE values ​​occurred because during this period there was an increase and decrease in both the use of fishing gear and fishing trips. For the yield value (MSY) the optimum fishing effort is 2,940 trips per year and the maximum sustainable catch value is 63,954 kg per year. If viewed based on the sustainable maximum catch value, the number of catches produced in 2020 and 2021 has exceeded the maximum catch limit (Cmsy), but the fishing effort has not exceeded the optimum fishing effort (Emsy). Meanwhile, the yield value of the utilization rate of brown shrimp resources in the last five years indicates that the utilization rate has increased drastically, especially in 2020 and 2021

Sustainable economic analysis and length weight relationship of Bullet Tuna (Auxis rochei) fishery in east area of Bali Strait, Indonesia

Abstract. Bintoro G, Sutjipto DO, Lelono TD, Semedi B, Sartimbul A, Wahyuni MT. 2023. Sustainable economic analysis and length weight relationship of Bullet Tuna (Auxis rochei) fishery in east area of Bali Strait, Indonesia. Biodiversitas 24: 3528-3535. Bullet tuna (Auxis rochei) is a small pelagic fish with an important economic value and is mainly caught by fishermen in the east area of Bali Strait, Indonesia. The high market demand for this fish has increased fishing efforts to achieve maximum catch, and this uncontrolled fishing activity will threaten its sustainability and economic potential. This study was conducted to determine stock status both biologically and economically. The length-weight relationship was calculated by measuring the length and weight of 1,200 samples of fish landed in the Pengambengan Archipelago Fishing Port (AFP) in Jembrana Bali Province from February to March 2020. The calculation of maximum sustainable yield (MSY), maximum economic yield (MEY), and equilibrium of open access (OA) were done by using secondary catch data from 2008 to 2019. Gordon Schaefer’s model analysis found that the values of YMSY and fMSY were 3,314 tonnes year-1 and 3,503 trips year-1, respectively. While the values of YMEY and fMEY were 3,160 tonnes year-1 and 2,750 trips year-1, respectively, which gave a maximum profit of about 1.4 billion USD year-1. In addition, the equilibrium of OA would be achieved when the fishing effort reaches 5,500 trips year-1 and the amount of catch reaches 2,237 tons year-1. The growth pattern of the bullet tuna was isometric, which indicates that the bullet tuna in the east area of Bali Strait has a proportional body shape. The utilization status of bullet tuna (A. rochei) is over-exploited.

TINGKAT PEMANFAATAN UDANG KARANG (Panulirus spp) BERDASARKAN PENDEKATAN MODEL PRODUKSI SURPLUS DI PERAIRAN KABUPATEN PANGKEP

Crayfish (Panulirus spp) is one type of Indonesian marine fishery resources that is very potential and has long been caught by fishermen in coral areas to find out the description of fishing gear, methods, and crayfish fishing areas (Panulirus spp) in the waters of Pangkep Regency and to find out the estimated utilization rate of crayfish using the MSY approach in Pangkep Regency. This research has been carried out by taking data in the form of primary data carried out from March 1, 2022 – April 30, 2022 and secondary data in the form of catch production data and fishing efforts (units) obtained from the Marine and Fisheries Service of Pangkep Regency for the 2016-2021 time period. The results of this study showed that the fishing gear used to catch crayfish (Panulirus spp) was a fixed gill net using a canoe boat as a tool. The process of catching crayfish includes setting, soaking and hauling. Coral fishing grounds are in rocky areas with the fishing season occurring from November to January. Based on the results of research using three surplus production models, it was concluded that the most suitable surplus production model for crayfish fisheries in Pangkep Regency is the Gulland model by showing a large (R2) and a small standard deviation. The maximum sustainable catch is 16,783.58 kg/year and the attempted catch is 12,496 units. The Utilization Rate (TP) and Capability Rate (TPU) have exceeded (yJTB) and (fJTB) with overexploited status.

Geo-spatial distribution and trends of trawl catch and bycatch off the south Konkan coast, Maharashtra, India

Trawl fishing is well-known for its high catch rate, but due to its non-selective nature, it is now widely acknowledged to have an impact on biodiversity and habitat. The geographical and temporal aspects of trawl catch, bycatch, discard, and ichthyofaunal trawl diversity along the south Konkan coast of Maharashtra, India, are contemplated in the current study. The data of 177 georeferenced trawl hauls, towed between 15°53’38”N to 17°34’52”N latitude and 72°54’29”E to 73°25’48”E longitude, revealed that maximum bycatch (70–110 kg/haul) and discard (60–110 kg/haul) regions were found towards the southern direction, near ecologically sensitive estuarine areas off the south Konkan coast, Maharashtra. The post and pre-monsoon seasons were found to be much more productive in terms of catches, while the post-monsoon and winter seasons had the highest species diversity 38.15% and 33.86%, respectively, with the winter season having higher discard rates. In the present study, bycatch contributed nearly 49% of the total catch, with the maximum catch per hour recorded in October (62.20 kg) and the discard per hour in January (14.59 kg). There were 134 different species of fish and shellfish recorded, and the family Carangidae (8.21%) was prominent in terms of species richness, followed by Penaeidae (6.72%), Clupeidae (5.22%), Engraulidae (5.22%), and Sciaenidae (4.48%). The results of various biodiversity indices confirmed that the studied region is blessed with rich and evenly distributed biodiversity. The mapped predictive values of trawl fishing showed a high fishing pressure zone towards the south off the Maharashtra coast, and it highlighted the need for suitable strategies for the conservation and management of fisheries resources to achieve long-term sustainability in that region.

Produktivitas dan Pola Musim Tangkap Ikan Peperek (Leiognathus spp.) di Teluk Banten

Ponyfish (Leiognathus spp.) is one of the dominant types of fish landed at the Nusantara Fishing Port (PPN) Karangantu. Its high-intensity fishing activities are feared to cause future problems with the sustainability of ponyfish resources. This study aims to calculate fishing productivity, sustainable optimal fishing effort, maximum sustainable catch, and determine the pattern of fishing season in Banten Bay. The research was conducted from April to June 2021 at PPN Karangantu. The fishing gear analyzed were fixed lift nets, floating lift nets, and seine nets. Fishing productivity was calculated from catch per unit effort; the maximum sustainable catch was analyzed using the Schaefer, Fox, and Walter-Hilborn regression models. The seasonal pattern of the ponies was determined from the Fishing Season Index. The results showed that pony fishing productivity in PPN Karangantu decreased from 2016 to 2020. The optimum fishing effort value and the optimum catch through the Schaefer model were 2088 trips/year and 276.12 tons/year, respectively; the highest fishing season occurred in November (145.5%) and the lowest in May (70.2%). Based on the analysis of the Schaefer, Fox and Walter-Hilborn models, the exploitation of Ponyfish (Leiognathus spp.) in Banten Bay can be said to be over-exploited.
 
 Keywords: catching season, Banten bay, Leiognathus spp., productivity

ESTIMATION OF THE STOCK OF INDIAN SCAD FISH (Decapterus russeli) LANDED AT THE SIBOLGA ARCHIPELAGO FISHERY PORT, NORTH SUMATRA

Indian Scad Fish (Decapterus russeli) are the most dominant small pelagic fish resources landed in the Sibolga Archipelago Fisheries Port. The production of Indian Scad Fish catches that are landed in PPN Sibolga on average fluctuates every year. Therefore, it is necessary to analyze the catch of Indian Scad Fish to control the level of exploitation and create effective fishing operations so that the utilization of Indian scad fish resources can run optimally and sustainably. This study aims to determine the percentage level of utilization of Indian scad fish (Depterrus russeli) that landed at the Sibolga Nusantara Fisheries Port, North Sumatra. This research was conducted in March – April 2022. The method used in this research is the survey method. The type of data collected is secondary data. The data analysis used includes standardization of Indian scad fish fishing gear, sustainable potential and optimum effort, total allowable catch (TAC), utilization rate, and effort. From the research results, it was found that the highest production of Indian scad fish catches in 2019 was 6,392 tons. Based on the calculation of MSY and the optimum effort in 2017-2021 of 5,934.97 tons/year, meaning that the maximum catch of Indian scad fish that can be caught is 5,934.97 tons/year and the number of allowable catches is 4,747.98 tons/year or 80% of the maximum catch and utilization rate of Indian scad fish for 5 years is 81.41%.

Redistribution of fisheries catch potential in Mediterranean and North European waters under climate change scenarios

The Mediterranean Sea is a hotspot of global warming where key commercial species, such as demersal and pelagic fishes, and cephalopods, could experience abrupt distribution shifts in the near future. However, the extent to which these range shifts may impact fisheries catch potential remains poorly understood at the scale of Exclusive Economic Zones (EEZs). Here, we evaluated the projected changes in Mediterranean fisheries catches potential, by target fishing gears, under different climate scenarios throughout the 21st century. We show that the future Mediterranean maximum catch potential may decrease considerably by the end of the century under high emission scenarios in South Eastern Mediterranean countries. These projected decreases range between −20 to −75 % for catch by pelagic trawl and seine, −50 to −75 % for fixed nets and traps and exceed −75 % for benthic trawl. In contrast, fixed nets and traps, and benthic trawl fisheries may experience an increase in their catch potential in the North and Celtic seas, while future catches by pelagic trawl and seine may decrease in the same areas. We show that a high emission scenario may considerably amplify the future redistribution of fisheries catch potential across European Seas, thus highlighting the need to limit global warming. Our projections at the manageable scale of EEZ and the quantification of climate-induced impacts on a large part of the Mediterranean and European fisheries is therefore a first, and considerable step toward the development of climate mitigation and adaptations strategies for the fisheries sector.

Utilization and Management of Pelagic Fisheries in West Sumbawa Regency, West Nusa Tenggara Province

Kabupaten Sumbawa Barat (KSB), Nusa Tenggara Barat Province has potential fishery resources. Based on Permen KP No.18 of 2014 concerning the Republic of Indonesia State Fisheries Management Area (WPPNRI), KSB marine is included in WPPNRI 573. The purpose of this study was to determine the sustainable potential of pelagic fisheries and their level of utilization. This research was conducted in KSB from January to November 2022. The research method used was a field survey method and a descriptive method. The results of the study showed that the relationship between effort and CPUE for large pelagic fish obtained a linear equation y = 12.067x + 277.6 with R2 = 0.1785. This equation explains the positive relationship between production and effort, meaning that fishing gear affects the production of large pelagic fish. the optimum effort value is 1674.90 trips per year and the maximum sustainable catch is 232,459.1 kg per year. Effort relationship with CPUE of small pelagic fish obtained a linear equation y = -18.575x + 11512 with R2 = 0.2817. This equation explains the negative relationship between effort and catch. This shows that fishing gear is not the main factor affecting the amount of production. the optimum effort value is 106917.700 trips per year and the maximum sustainable catch is 992998.139 kg per year. The utilization rate value is 2.049%, with an effort level value of 0.001%. This study concludes that the potential and level of utilization of pelagic fisheries in West Sumbawa Regency are still below the sustainable potential.

Current state of the Sea of Azov main commercial fishery resources and ways to restore them

The paper presents the result of analyses of the Azov Sea fishery resources state for the last 15 years of the last century up to the present time. The information on quantitative and qualitative composition of commercial catches is obtained from the data of fishery statistics. Changes in temperature and salinity and their anomalies relative to mean annual values are highlighted. The first four commercial species with maximum catches have been identified: anchovy, kilka, gobies and Redlip mullet. The dynamics of their ratio, at different periods of the current century, may indicate the influence of external conditions (temperature, salinity, etc.). The forecast on increase of catches of the listed species and recommendation on development of the Azov sea fishery development programme, including all directions of fishery, introduction of the newest achievements of science and technology in development of aquaculture and other branches connected with rational use of aquatic biological resources of the sea are given.

Analysis of trawl-net operation and major fish landings at Andaman and Nicobar Islands, India

Trawl-net is an important fishing gear in Andaman and Nicobar Islands (ANIs) India since three decades with minimum number(n=10) of boats meeting the daily fish consumption of Islanders with minimum costs. A study was carried out between 2014 to 2018 to investigate the major fish landings of Trawl-net in the ANIs coast. The trawl-net landing is occurring only from Junglighat fish landing centre(FLC) which is having loading and unloading facilities in ANIs. The total number of FLC visits, fishing-trips, operations and fish-landing of trawl-net recorded during this period were 692(n), 533(n), 7561(n) and 691(tonnes) respectively. The maximum fishing-trips(149) and fishing-operations(2086) occurred during the year 2018 and minimum of same (87 and 1218) occurred during 2015. Similarly, the maximum(170.51tonnes) and minimum (109.33 tonnes) of fish landings were observed during the year 2014 and 2015 respectively with an average of 138.21±10.54tonnes/year. The contribution of trawl-net landing amongst other gears was 17.8% including fin-fishes(598.7tonnes) and shell-fishes(115.34tonnes) during the study period. The trawl-net operation was occurring at very few fishing grounds(n=14) in ANIs and the maximum fish catch occurred in the Coast of Havelock Island (26.7%). Totally 52 genera of fishes were recorded in trawl-net landings under 37 families in which Leiognathidae was found more dominant(21.38%). Altogether 21 Trawl-net validations were conducted at each PFZ and Non- PFZ during the period. The fishes captured at PFZ 3288kg with an average of 156.6±13.5 kg/operation and at Non-PFZ 1237kg with an average of 58.9±5.3kg/operation. The minimum range of fish cost in the market was maintaining in this Island due to the trawl-net landings, in-spite of there was controversy of non-selective fish catch and by-catch in trawl-net fishing.

Penerapan Limit Fungsi untuk Mencari Keuntungan Maksimum Ditinjau dari Biaya Marginal

Marginal costs are changes in total costs in the form of increases or decreases in total costs due to changes in the quality of goods or services. Through the types of production costs used as processing costs, it will be seen to what extent the use of capital will be used and profits will be obtained. This analysis will help to what extent a company can determine the planning for the business that is built, whether to get maximum or minimum profits. This study uses literature study, which is research in which data sources and data collection are obtained by taking library data, reading, recording and processing the data as research material. Based on an analysis of literature data regarding "Maximum Profits from Fishermen Business in East Balikpapan District" the results obtained are the maximum profit in terms of marginal costs, namely the maximum profit for the total catch of fishermen and occurs at a maximum catch rate (Q) of 159.92. So it was concluded that the fishing business in East Balikpapan District had not yet achieved maximum profit, because the fishermen's catch exceeded the maximum catch level requested.