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This study compiled and remodelled length selectivity studies carried out on fish caught with gill nets and trammel nets in the inland fishery in Türkiye and evaluated them based on both the initial reproduction length and minimum landing size of species. The required data for the study were obtained through a literature review. 34 selectivity studies in total were identified, and 26 (76.5%) of them were carried out with gill net while the remaining 8 (23.5%) were conducted with trammel net. 24 of the studies were carried out according to SELECT (Share Each Length-class's Catch Total) and 10 of them according to Holt (1963). In conclusion, it was found that minimum conservation reference size (MCRS) values determined by the Ministry in the inland fishery in Türkiye were substantially greater than lengths at first maturity (LFMs) of species and that fishing gears used for fishing typically tended to fish mature individuals above MCRS. The major problem in terms of management is that different ideal mesh sizes are applied to different fish species that are in the same fishing place. Set nets with an ideal-mesh size for a species has a potential of catching individuals below LFM of other species in the same fishing grounds. It is thought that this problem can only be resolved with the Ecosystem Approach to Fisheries Management (EAFm). [ABSTRACT FROM AUTHOR]

Context: Swimming crab is a vital fishery resource and a valuable source of income in the southern East China Sea, but it lacks management strategies, especially when using different fishing gear. Aims: This study aimed to determine the effects of spatial–temporal conditions and vessel capacity on swimming crabs by using different fishing-gear types in the Taiwan Strait (TS). Methods: We used generalised linear mixed models (GLMMs) to investigate data from Taiwanese vessels (2011–2019) on how spatial–temporal conditions and vessel capacity affected the catch of swimming crabs when using trawls, gill-nets and traps. Key results: The results showed that the traps (>80.0%) caught more swimming crabs in the TS than did the gill-nets (6.6%) and trawls (8.0%). Additionally, the GLMM analysis showed that Charybdis feriatus , Portunus pelagicus and Portunus sanguinolentus catches by traps and trawls were significantly affected by different fishing locations, climate events, work hours and vessel sizes. However, for gill-nets, spatial–temporal conditions and vessel capacity did not affect the catch of C. feriatus. Conclusions: Monitoring fishing efforts and environmental factors is vital to understanding their impacts on marine ecosystems. Implications: These findings enable future sustainable crab fishing through harvesting strategy planning, ecosystem management and spatial–temporal governance. The catch performance of fishing gear depends on species' behaviour, habitat, fishing grounds, fishing regulations and oceanographic conditions. Besides, to optimise the catch, experienced fishermen mostly use the right gear at the right time and place. Therefore, the fact that baited traps more efficiently target swimming crabs than do other gear types may be due to two critical factors, namely, the habitat of the crabs in the benthic area and the chemoreceptive sensory behaviour of crabs in detecting the bait. [ABSTRACT FROM AUTHOR]

The present study assessed the impact of regime shifts on the ecosystems that support fisheries in the coastal area of Kyoto Prefecture, the Sea of Japan. Ecopath models were constructed during cold (1985) and warm (2013) regime periods, when the fishery structures were different. Both models evaluated by pre-balance diagnostics were reliably constructed. Multiple ecosystem indicator values were compared between the two periods to assess changes in the ecosystem structure and the impact of fisheries on the ecosystem. The major change in catches in the coastal area of Kyoto Prefecture between 1985 and 2013 was that the Japanese sardine drastically declined and Spanish mackerel increased. The primary production requirements of fisheries (%PPR) were higher in 1985, reflecting the greater impact of sardine. The mean trophic level of catch and system omnivory index suggested that stability of trophic network increased after the sharp decline in sardine biomass. The %PPR, the loss of secondary production due to fisheries exploitation and probability analysis of fishery sustainability suggested that the fishery structure in 2013, which was dominated by set nets, contributed to a more sustainable fishery than the structure in 1985, when fishery was dominated by purse seines and set nets. [ABSTRACT FROM AUTHOR]

New attempt to answer the questions: 1) what aquatic biological resources are possessed in the Russian Far-Eastern Seas and North Pacific and what is their quantity? 2) which of them and how many are caught annually? 3) are these resources managed rationally in Russia? 4) and what is the reason for current situation and can it be improved? Based on the data of trawl surveys, a GIS is created with maps of the biological resources distribution, separately for actually harvested, potentially commercial, and non-commercial ones. The biomass, potential yield and its cost are calculated for the Chukchi, Bering, Okhotsk, and Japan Seas and North-West Pacific. These water bodies are ranked by their value for commercial fisheries. The obtained estimates are compared with the data on annual catch, export, import, and consumption of fish products in Russia. Possibility of larger landing is concluded for each water body, in terms of the harvested species biomass. The harvest from the Okhotsk Sea alone can reach more than 5.2 million tons that exceeds the level of «strategic ceiling» for the entire Russian fishery proposed in «Strategy for development of the fisheries complex of Russian Federation for the period to 2030». For the whole water area under consideration, this level can be exceeded by 3.5–4.7 times, or even by 5.6 times if the potentially commercial species will be exploited. Dynamics of domestic catch, trade and consumption of the biological resources are analyzed. The conclusion is that socioeconomic conditions rather than the state of biological resources are the reason that Russia still does not harvest so much. Some measures are proposed to improve the management of the Russian fishery industry. The obtained results cah alsobe used for maintenance rational use of the biological resources, food security, and nature protection, including evaluation of cost for biological resources in certain water bodies and assessment of damage caused to the nature and biological resources by pollution, construction, oil and gas production, or technogenic accidents.

Understanding the depredation process is pivotal to the management of conflicts between wildlife and human activities. Depredation by marine mammals on fisheries occurs when animals 'steal' fish from the fishing gear, causing catch loss and damage to gear and catches. The common bottlenose dolphin is a vulnerable species and is the main depredator of coastal static net fisheries in the Mediterranean Sea.The nature and extent of the phenomenon is still poorly understood since evidence is often incomplete or inconsistent mostly due to the different methods used to measure depredation.Here, passive acoustic monitoring devices were used to estimate the consistency between dolphin acoustic detection in proximity to the net and direct dolphin observations and catch measurements at different sites in Sardinia (north‐western Mediterranean Sea). Further, some factors influencing depredation (fishing duration and fishing net length) and changes in catch amount and composition were evaluated.The frequency of dolphin detection based on direct dolphin observations was significantly lower than that based on acoustic monitoring; the latter was related to the amount of catch. Thus, the measurement of catch was more realistically related to depredation than direct dolphin observations. Further, dolphin depredation was related to the duration of the fishing operation.The measure of depredation and catch loss provided here can be used to realistically estimate the damage suffered by fishers and provide preliminary insights to guide the development of an approach for sustainable coexistence between dolphins and fisheries. [ABSTRACT FROM AUTHOR]

Assessment of fish stocks is especially important to avoid overfishing and obtain sustainable fishing policies, and there are many stock assessment methods such as XSA, VPA, BMS, CMSY, and MSVPA to analyze fish stocks. However, these assessment methods require an important amount of data for fish stocks such as diet data, natural mortality, fishing mortality, abundance index of species, predator ratio estimates, and so on. Unfortunately, we do not have such data for most of the fish stocks, and obtaining such data requires an important amount of money and time, but we still can predict important information about fish stocks such as biomass of fish stocks, the maximum sustainable yield, the biomass of fish lost or gained due to predator-prey relations, and even can track the effect of harvesting on predator-prey relations by building a mathematical model for fish populations and implementing a stability analysis. To obtain these outputs, we only need landing data and implement a parameter estimation constrained on stability conditions derived from the stability analysis of the mathematical model. Shortly, this study shows us how important stability analysis is to obtain important information about fish populations in the absence of important data. [ABSTRACT FROM AUTHOR]

Information on the stock status of giant catfish Netuma thalassina (Rüppell, 1837) is meagre due to lack of catch and effort data. Therefore, we reconstructed catch and effort data of the giant catfish fishery in Tamil Nadu, India waters from 2001 to 2020. Catch and effort data were analyzed with Catch and Effort Data Analysis (CEDA), Catch Maximum Sustainable Yield (CMSY) and the Bayesian state‐space implementation of the Schaefer production Model (BSM). Results indicated that giant catfish resources were fully exploited and reached the stage of overexploitation in 2014. Considering the high vulnerability to climate change, very high susceptibility to fishing, increased fishing effort and fully exploited status of giant catfish fishery, we propose a significant reduction of fishing effort to ensure sustainable exploitation. [ABSTRACT FROM AUTHOR]

Small-scale fisheries along the Swedish west coast are often operated by using small vessels, targeting multiple species by means of pots and gillnets. Fisheries using pots targeting shellfish such as European lobster (Homarus gammarus), and edible crab (Cancer pagurus) along the Swedish west coast have a relatively high economic value. However, gillnet fisheries targeting demersal fish are currently diminishing primarily due to depleted fish stocks and increased seal depredation. Small-scale fisheries are considered sustainable fisheries due to the use of selective gears and low energy consumption. To be able to retain and promote a sustainable small-scale fishery, there is a need to develop an economically viable fishery, where selective, seal-safe and sustainable gear is utilized. One potential way forward could be to develop a pot to be used for multiple target species traditionally caught in pots and gillnets. Since both shellfish and cod (Gadus morhua) can be caught in pots, the objective of this work was to develop a multispecies pot targeting lobster, edible crab and cod. Seven multi-species pots were developed and tested off the west coast of Sweden between 2015 and 2017. The catch rate, defined as catch per pot per day (CPUE) of lobster, edible crab and cod, was evaluated taking into regard fisheries-related variables such as pot type, bait, soak time, seal damage and abundance of species in the pot. The relative CPUE of lobster and cod was highest in larger pots with two chambers and three open entrances. The highest CPUE for lobster was 0.24 individuals per pot and the highest CPUE for cod was 0.17 individuals per pot. Pots with entrances equipped with funnels, preventing cod from escaping, also had a high cod CPUE (0.23 individuals per). The CPUE of crabs was not affected by pot type. For cod, lobster and crab, the CPUE significantly decreased with increasing soak time. Seal damage only occurred when cod were trapped in the pots and the CPUE of cod was higher in pots subjected to seal damage, indicating that seals raid pots specifically when cods are trapped inside.

Marine habitat degradation resulting from human activities and environmental pollution has led to serious deterioration of marine fishery resources. To address this issue, countries worldwide are exploring sustainable fishery approaches. Installation of artificial reefs (AR) is rapidly increasing. AR have been widely constructed globally to conserve fishery resources and improve marine habitats. As an important biological group of marine fishery resources, nekton are widely evaluated to determine the effects of ecological restoration and resource conservation. In the current study, we compared the dynamic properties of taxonomic diversity and the eco-exergy of nekton community from 2 to 14 years after AR construction in Dalajia, China. The results indicated that the species number and density of nekton significantly increased after AR construction. Siganus oramin became an absolute dominant fish species in the reef area and its surroundings. The species diversity and evenness of the nekton community decreased, whereas species richness increased. The abundance, biomass, and eco-exergy of the nekton community increased over time because of the dominance of fishes. Our results highlight that AR can increase and conserve fishery resources, improve the structure of the nekton community, and increase ecosystem stability. But, at the same time, the dominance of S. oramin can interfere in the reef community. The explosive growth was quantitatively and qualitatively higher than that of other species, the diversity and evenness indices showed a decreasing trend, although the number of nekton species was significantly higher than that in the background survey and CA habitat during the same period.

In Japan, fisheries' product has decreased since the 1980s, and the government amended the fisheries law in 2020 to shift to managed fisheries. However, awareness of seafood sustainability is still low. This study identifies the reason for the low awareness and states the necessary actions to increase sustainable seafood consumption. The proactive stakeholders in seafood supply were surveyed to determine the current status of sustainable seafood sales. Marine Stewardship Council-certified fishers and MSC's Chain-of-Custody certification holders answered the questionnaires. Fishers showed a positive attitude, citing proactive sales channel expansions and contributions to sustainability. Distributors were primarily passive, mainly because they obtained the certification at the request of their clients, and about half of them did not disseminate information between consumers and suppliers. Both fishers and distributors expect the government to promote campaigns and education. The stages of the awareness of producers, intermediary trade, and retailers are different and did not align. Therefore, if the supply chain stakeholders proactively educate themselves, choose sustainable products from the fishers, and pass the sustainability information to the consumers, sustainable seafood consumption would progress. [ABSTRACT FROM AUTHOR]

This paper studies an economy specialized in fisheries facing a rising marine litter problem. We present a dynamic optimization model to explain the mechanism through which marine litter causes inefficiencies in the fishery sector. We do so by investigating the properties of the model when the marine litter externality is internalized through the price of fish. We find that if the marine litter externality is neglected, fish harvest increases, and ocean quality deteriorates. We subsequently explore the possibility of introducing an incentive scheme where marine litter can be traded in a hypothetical market. The introduction of a so-called fishing-for-litter market removes the inefficiencies caused by fishermen neglecting marine litter and provides a direct incentive for them to maximize overall welfare through resource recovery, i.e. by converting plastic waste into a new valuable resource.

Stock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species. [ABSTRACT FROM AUTHOR]

The Straits of Malacca provides half of Malaysia's total marine fish and seafood supply. Due to depleted fish stock, the Malaysian Government has established a comprehensive legal framework to reduce overfishing in the Straits over the last five decades. However, there are limited scientific studies on the current status of stock recovery. This paper aims to use bioeconomic approach to determine the current trawl fishery status in the Straits. Various statistical tests showed that the Clarke-Yoshimoto-Pooley model was better than the Schnute model in predicting and thus used to estimate the crucial bioeconomic parameters. The current yield and standardised effort of 239,692 tonnes and 931,692 standard fishing days were very close to the estimated biological maximum sustainable yield (239,915 tonnes) and above 18 % of the standardised effort (763,649 standard fishing days) to achieve it. The maximum economic yield was estimated at 201,542 tonnes while the corresponding standardised effort was 396,799 standard fishing days indicating serious economic overfishing in the Straits. If the current effort can be reduced by 57 %, fish biomass and economic rent will increase by 97 % and 835 %, respectively. A price sensitivity analysis predicted that demand-pull fish price inflation could exacerbate the overfishing problem, particularly under unrestrained environment. A 50 % increase in price could lead to a 132 % increase in fishing effort from the base case. The findings of this paper provide valuable insights for fishery managers to refine their existing fishery management program to achieve sustainable fishery for the future. [ABSTRACT FROM AUTHOR]

New variants of canned skipjack tuna have been developed by large manufacturers of canned tuna in the Philippines. This study analyzes the expenditure and price elasticities of canned tuna and determines the implications for sustainable fishery. An AIDS (almost ideal demand system) model incorporating an income group variable was used to estimate these elasticities. This study utilized a pooled time series data of 459 weekly point-of-sale observations from 2010–2012 of three store branches of a large supermarket chain in southern Philippines. The point-of-sale data suggest that canned tuna consumption is composed mostly of tuna in sauce with vegetables followed by tuna in oil and tuna in sauce without vegetables. For both high- and low-income groups, the expenditure elasticities have the expected positive signs – indicating that as the income of consumers’ increases, the quantity demanded for canned tuna in three product mediums also increases. For high-income consumers, consumption of tuna in sauce with and without vegetables is more responsive to income changes. The own-price elasticities of the three product mediums across high- and low-income store branches have negative signs – suggesting that as their own price increases, the quantity demanded for these products decreases. The cross-price elasticities suggest that tuna in sauce with vegetables is a substitute for tuna in oil and in sauce without vegetables for both income groups. Thus, promoting more use of vegetables through product development may lead to a lower volume of tuna meat used in canned tuna products, which contributes to addressing tuna resource sustainability. [ABSTRACT FROM AUTHOR]

In the Mediterranean Sea, more than 121,000 sea turtles are incidentally caught each year by a variety of fishing gears, with more than 33,000 deaths and a mortality rate ranging from 10 to 50% depending on the type of fishing gear. Defining how to engage the fishers who are directly involved in incidental catches of turtles is critical to raise their interest, increase awareness and foster their collaboration with the scientific community and authorities. We developed a conceptual model to define the objectives of sea turtle conservation (Final Targets, FTs) at a management, technical, educational, and social level. The achievement of FTs was assessed through four Indicators (interest, scepticism, awareness, cooperation) based on the perception and behaviour of fishers. A 3-phase roadmap was set to engage fishers: 1) Meeting , it is the initial contact between the scientific community and the fishers to create baseline information on where, when, and how bycatch occurs; 2) Deepening the knowledge , it mainly consists on trainings to increase fishers' awareness of good practices and sustainable fisheries; 3) In the field , where scientists and fishers test innovative bycatch reduction devices (BRDs) aboard on commercial fishing vessel to comprehend the perspective of fishers in terms of the technical solutions proposed by scientists. Combining a theoretical and an empirical approach, this study provides successful indications (bycatch hot-spots, technological innovation of fishing gear, communication strategies, eco-labelling, improved sea turtle survivability) on how to achieve large-scale sea turtle conservation, which could be replicated in other areas. • 120,000 sea turtles are incidentally by caught each year in Mediterranean Sea. • Fishers' engagement is critical in sea turtles conservation. • Fishers engagement roadmap was outlined combining theoretical-empirical approaches. • The study gives successful indications to achieve large-scale sea turtle conservation. [ABSTRACT FROM AUTHOR]

The EU Landing Obligation (LO) bans discards to incentivize a more selective and sustainable fishery. This regulation may induce a cost to the fishing industry that could be transferred to final fish consumers. We aim to assess the consumers’ reservation price for a sustainable and selective fishery. The methodology follows two steps: We first assess the value of the reservation price (willingness to pay, WTP) for a sustainable and selective fishery by using contingent valuation methods from a comparative perspective in Spain and Italy. We then attempt to empirically assess the components of WTP by using an original model specification that, unlike those presented in the literature, exogenizes socio-economic variables and uses ideological indicators to explain WTP in a two-line simultaneous model estimated by instrumental variable regression. The results show a positive, though low, WTP across the two samples, and very different impacts of estimated coefficients on the WTP for the two samples. A preliminary interpretation of this divergence highlights that Italian consumers consider LO-incentivized sustainable fishery a pure public good linked to issues of legality, and Spanish consumers consider it an impure public good linked to environmental issues. These differences may indicate how strongly the institutions and the policies in each region are perceived by a different human capital structure. They may also indicate that the problem, the perceptions of it and the solutions to it differ according to the context.

Cod has been one of the fish that human beings have loved. It has not been long since it recovered from its situation of almost extinction in all oceans of the world. The historical process of its depletion and recovery raises key questions: Who owns the common pool resource? Who should manage the common pool resource? These have led to several strategies and countermeasures, some of which have been successful at stemming species decline. In South Korea, cod has long recorded high production due to its high demand as a favorite fish species. However, the phenomenon of declining and depleting cod led to a situation where we had to take seriously the question of who and how to manage cod. Having repeatedly experienced the exhaustion and recovery of the resource, fishermen had to think seriously about the crisis of their profession and the sustainability of the fishery. To achieve it, fishermen organized the fishing community, made a set of rules, and began common activities to manage resources and use fishing grounds. The voluntary resource management activities and practices of the fishing community began to take effect as they interacted with local governments and the fisheries authorities. Fishermen are now carrying out cultural activities not only for their livelihood, but also for the sustainability of cod fishing. In this paper, I will examine how the fishing community strategy and practice interacted with the system and achieved successful results through the case analysis of cod fishing in Geoje. [ABSTRACT FROM AUTHOR]

Passive bottom-set nets are the most widely used fishing gears in Mediterranean small-scale fisheries (SSFs). Trammel nets, in particular, have key advantages such as their ease of use and handling and high capture efficiency for numerous commercial species. However, they entail high discard rates (5-44% of the total catch) connected to high mortality, thus exerting an adverse impact on benthic communities, besides catching individuals of commercial species under the minimum conservation reference size (MCRS) and specimens of protected species. Fish pots are seen as alternative and a more sustainable gear type that allow reducing discards in SSFs. In this study, a collapsible pot was tested at three coastal sites in the north-western Adriatic Sea (GFCM GSA 17) to compare its catch efficiency with that of the local traditional trammel nets. Data analysis demonstrated a similar catch efficiency for the commercial species, both among sites and as a whole. Moreover, the trammel net caught a larger amount of discards, both in terms of species number and of CPUEW. The catch comparison study involved the two most abundant landed species, common cuttlefish Sepia officinalis and annular sea bream Diplodus annularis. The pots were more effective for S. officinalis, whereas the trammel net was more effective for the shorter length classes for D. annularis, which were mostly under the MCRS (12 cm). The innovative pots could provide a valuable alternative to the trammel nets traditionally used in the Adriatic Sea, at least in certain areas and periods. Their main advantages include that they do not require a different rigging and they can be used without bait, while their foldable design allows large numbers to be easily loaded on board SSF vessels. The results of this pilot study indicate that pots can achieve the objectives of reducing discards and bycatch in SSFs without penalizing the catch of commercial species. [ABSTRACT FROM AUTHOR]

Small‐scale driftnets (SSDs) have been historically used in the Mediterranean without major environmental concern. The introduction of large‐scale driftnets caused unwanted catches of protected species. Specific regulations were therefore issued in European waters, culminating in a proposed moratorium on SSDs. This study aimed to characterise the SSD fishery targeting anchovy (menaide), evaluating its environmental sustainability, economic performance and social relevance. In 2013, a survey by interviews, logbooks and observers on board assessed the order of magnitude of this fishery in terms of fishing capacity and activity, volume of landings and revenues. The menaide fleet consisted in 60 vessels <12 m overall length, moored in little harbours in southern Italy. These nets are highly selective: the target species, European anchovy, Engraulis encrasicholus (L.) and sardine, Sardina pilchardus (Walbaum), dominates the catches, while discards are negligible. The anchovies caught are of high quality and large size; the high prices support fish processing by local factories. Moreover, the results of a SWOT analysis demonstrated that replacing SSDs with a semi‐industrial fishery, like purse seining, would increase impacts on the ecosystem, and a loss of socio‐economic opportunities for several coastal villages. These findings support the option of keeping SSDs operating, in the framework of specifically oriented management measures. [ABSTRACT FROM AUTHOR]

Wild populations of the native European flat oyster (Ostrea edulis) are nowadays rare. Worldwide, flat oyster populations have declined due to overexploitation, diseases and pollution. Yet, in the Limfjorden, Denmark, a small but persistent population of wild flat oyster have endured for more than 165 years, which has sustained a unique fishery on wild oyster beds. Over time, fluctuations in the wild population size has had implications for the fishery, alternating between a large population with high yields, and too small to withstand a fishery. The flat oyster fishery has been alleged to cause these unpredictable fluctuations in the population. However, the combined effect of natural variation (e.g. water temperature) and the fishery has not been investigated. Here we indicate that summer water temperature is an important factor causing fluctuations in the flat oyster population, thought to be due to its influence on recruitment success. Whereas the fishery often constitutes a minor part of the net oyster mortality. We found a positive correlation between summer water temperature and increased oyster landings ≥5 years later. Our results demonstrate the importance of adaptive management for the oyster fishery in the Limfjorden, which has ensured the survival of the flat oyster population, even when the oyster population has been low. These results highlight that management based on annual stock assessments, closed areas with brood stock, and dynamic annual total allowable catch, can ensure the persistence of an endangered oyster species and support a sustainable fishery. [ABSTRACT FROM AUTHOR]

Scoliodon laticaudus constitute a major fishery along the north‐west maritime states of India. Despite its contribution to the fishery, there is a dearth of information about the reproductive characteristics of the species in the region. The limited fecundity and its distribution in sensitive ecosystem could make it vulnerable to the impacts of targeted fishing and habitat degradation. Therefore, the present study was envisaged to collect information about the reproductive strategy of the shark which is essential for developing proper management measures for the sustainable exploitation of the resource. A total of 1,277 S. laticaudus specimens were studied to collect information about the maturity parameters, reproductive periodicity and reproductive potential of the species from the Gujarat coast of India. The length frequency distributions for both the sexes showed that mean and modal lengths of the exploited shark were 40.5 cm and 47.5 cm, respectively. Male and female sharks were found to mature at lengths of 33.8 cm and 35.8 cm, respectively which were lower compared to the predominantly targeted length group of the fishery. Though large and ripe ova were observed along with small developing ova throughout the year in the ovaries of the shark, significant increase (p ≤ 0.01) in mean ova diameter was observed during March and April followed by October and November which suggest the peak reproductive period of the shark. There was a significant relationship (p ≤ 0.01) between maternal body size and litter size where the larger females were recorded to produce more number of embryos compared to the smaller ones. The actual number of embryos carried by a single female ranged from a minimum 8 to a maximum of 19 embryos per pregnant female, with a mean embryo number of 10 per pregnant female. The higher mean size of embryos was recorded in August and September which coincided with the highest number of post‐partum females and therefore, might be considered as the major parturition period. The length at birth (L0) was calculated to be 13.7 cm. The breeding behavior of the species appeared to be continuous as developed embryos were observed throughout the year. The present study provides vital information for deriving the appropriate size and time for the sustainable exploitation of the resource. Further study should be conducted to understand the relationship between spawning stock biomass and recruitment dynamics considering the lower reproductive potential of the species so that the optimum spawning biomass could be assessed to ensure sustainability of this resource. [ABSTRACT FROM AUTHOR]

The early life of fish larvae is important to understand the entire life history of the fish. At this phase, larvae movement is very weak and dependent on the movement of water currents. This study aims to determine the distribution and abundance of fish larvae in the waters south of the Port of Tanjung Luar, West Nusa Tenggara, Indonesia. Sampling of fish larvae were done at five stations at waters around Alas Strait and Indian Ocean south of East Lombok. Sampled were collected from 5 different depth: 0-200 m, 201-1000 m, 1001-2000 m, 2001-3000 m and >3000 m. A total of 122 fish larvae were collected which belong to 26 families and varied compositions among observation stations. The samples was dominated by Scombridae family (18 %), followed by Carrangidae and Blenniidae (13.1% and 6.6%, respectively). The highest abundance was occurred in station V (0-200 m) of 125 individuals.1000-1m3. It showed that inshore/shallow waters have more abundance than offshore/deep waters. The findings from this study can be basic information for the authorities to establish sustainable fisheries policy. [ABSTRACT FROM AUTHOR]

Next to excessive nutrient loading, intensive aquaculture is one of the major anthropogenic impacts threatening lake ecosystems. In China, particularly in the shallow lakes of mid-lower Changjiang (Yangtze) River, continuous overstocking of the Chinese mitten crab ( Eriocheir sinensis) could deteriorate water quality and exhaust natural resources. A series of crab yield models and a general optimum-stocking rate model have been established, which seek to benefit both crab culture and the environment. In this research, independent investigations were carried out to evaluate the crab yield models and modify the optimum-stocking model. Low percentage errors (average 47%, median 36%) between observed and calculated crab yields were obtained. Specific values were defined for adult crab body mass (135 g/ind.) and recapture rate (18% and 30% in lakes with submerged macrophyte biomass above and below 1 000 g/m) to modify the optimum-stocking model. Analysis based on the modified optimum-stocking model indicated that the actual stocking rates in most lakes were much higher than the calculated optimum-stocking rates. This implies that, for most lakes, the current stocking rates should be greatly reduced to maintain healthy lake ecosystems. [ABSTRACT FROM AUTHOR]

Declines in the mean size of harvested organisms may indicate overexploitation. In the present study, temporal patterns in the mean size of the four main commercial shark species of Western Australia were evaluated. Unlike commonly observed for other shark populations, there were no strong temporal patterns in the mean size of gummy, dusky and whiskery sharks, whereas the mean size of sandbar sharks showed a gradual increase since 1993. These observations add further evidence that sharks can be fished sustainably when adequate monitoring, assessment and management actions are implemented. [ABSTRACT FROM AUTHOR]

Stock assessment studies of Sardinella Lemuru Bali strait indicate overfishing. The growth of fishing vessel numbers result on fish biomass stock reduction. Sustainable fishery management in overfishing area can be done by limiting number of fishing effort. There are three kinds of methods approach on determine number of fishing effort and total allowed catch (1) Maximum Sustainable Yield (MSY), (2) Maximum Economic Yield (MEY) and (3)Maximum Social Yield (MScY). Sustainable fishery has three main aspect as its indicators; ecology, economic and social. This research attempts to simulate three kinds of methods to the indicators of sustainable fishery (1) biomass fish stock as ecological aspect, (2) profit of purse seine fishing vessel as economical aspect and (3) numbers of fishers involved in the business of marine capture fishery represents social aspect. System dynamic method and powersim software are used in simulation model. Simulation output shows that fish biomass stock can be maintain in sustainable level by applied fishery policy. Limiting number of fishing effort create balancing between fish stock natural growth and fish harvest. This policy starts to apply on year 2010 in simulation model and run until 2030 to forecast future condition of fish biomass stock.