We have analyzed the development of “Broad-Scale Seabed Habitat Maps” (BSHM) and their potential use in a European context with regard to the EU Marine Strategy Framework Directive (MSFD) implementation, MPA designa...We have analyzed the development of “Broad-Scale Seabed Habitat Maps” (BSHM) and their potential use in a European context with regard to the EU Marine Strategy Framework Directive (MSFD) implementation, MPA designation and network assessment as well as other applications of BSHMs. The analyses are anchored in BSHMs developed by a series of interlinked EU projects (e.g. UKSeaMap, BALANCE, MESH, Mesh Atlantic, EUSeaMap 2012, and EUSeaMap 2016) and all maps are based on environmental data. Some EU Member States have used BSHMs as part of their MSFD Initial Assessments published in 2012. However, we conclude that BSHMs are a prerequisite for another key MSFD activity, i.e. mapping of potentially cumulative effects of multiple human stressors. Further, BSHMs seem to play a growing role with regard to evidence-based assessments of MPAs. With the upcoming second round of MSFD Initial Assessments due in 2018, including assessment of potentially cumulative pressures, there seems to be an increasing need for more BSHMs nationally, regionally and on a European scale.展开更多
Functional genes and gene expression have been connected to physiological traits linked to effective production and broodstock selection in aquaculture, selective implications of commercial fish harvest, and adaptive ...Functional genes and gene expression have been connected to physiological traits linked to effective production and broodstock selection in aquaculture, selective implications of commercial fish harvest, and adaptive changes reflected in non-commercial fish populations subject to human disturbance and climate change. Gene mapping using single nucleotide polymorphisms (SNPs) to identify functional genes, gene expression (analogue microarrays and real-time PCR), and digital sequencing technologies looking at RNA transcripts present new concepts and opportunities in support of effective and sustainable fisheries. Genomic tools have been rapidly growing in aquaculture research addressing aspects of fish health, toxicology, and early development. Genomic technologies linking effects in functional genes involved in growth, maturation and life history development have been tied to selection resulting from harvest practices. Incorporating new and ever-increasing knowledge of fish gehomes is opening a different perspective on local adaptation that will prove invaluable in wild fish conservation and management. Conservation of fish stocks is rapidly incorporating research on critical adaptive responses directed at the effects of human dis- turbance and climate change through gene expression studies. Genomic studies of fish populations can be generally grouped into three broad categories: l) evolutionary genomics and biodiversity; 2) adaptive physiological responses to a changing environment; and 3) adaptive behavioral genomics and life history diversity. We review current genomic research in fisheries focusing on those that use microarrays to explore differences in gene expression among phenotypes and within or across populations, information that is critically important to the conservation of fish and their relationship to humans [Current Zoology 56 (1): 157-174, 2010].展开更多
This paper exemplifies a primary step towards eliciting primary and secondary stakeholders’ views on management issues pertaining to kingfish fishery in Oman, and potential options for effective management of the fis...This paper exemplifies a primary step towards eliciting primary and secondary stakeholders’ views on management issues pertaining to kingfish fishery in Oman, and potential options for effective management of the fishery using questionnaire surveys and focus group interviews. There was consensus from stakeholder groups which included fishers, fishery managers, and fishery scientists that the current stock condition is not biologically sustainable. It is found that fishing effort control and technical measures are preferred to catch control by both groups. The role of mass media and the traditional institution in communicating fisheries issues are found to be relatively minor. Although the overall rating on the comprehensiveness of the proposed plan is promising, there are significant differences between the two groups with regard to legislative arrangements (χ<sup>2</sup> = 24.793, p-value = 0.000), management goals (χ<sup>2</sup> = 16.206, p-value = 0.001), operational objectives (χ<sup>2</sup> = 19.884, p-value = 0.000), performance indicators (χ<sup>2</sup> = 15.524, p-value = 0.001), and measures (χ<sup>2</sup> = 13.483, p-value = 0.004). Policy implications of the key findings are discussed in both national and regional contexts. Management authorities can use these findings to design an appropriate plan of actions for achieving sustainability in this fishery.展开更多
Commission for the Conservation of Antarctic Marine Living R esources acts as the executive body for Antarctic fisheries management with Convention on the Conservation of Antarctic Marine Living R esources( CAMLR Conv...Commission for the Conservation of Antarctic Marine Living R esources acts as the executive body for Antarctic fisheries management with Convention on the Conservation of Antarctic Marine Living R esources( CAMLR Convention) as the legal framework. As the only multilateral agreement for the comprehensive management of Antarctic marine living resources,CAMLR Convention has received a wide international recognition. This paper analyzes the highlights of CAMLR Convention in Antarctic fisheries management,namely,open access to membership,sophisticated institutional structure,capability of keeping pace with the times,diplomatic wisdom,measures against IU U,advanced fisheries management philosophies,etc. Meanwhile,Antarctic fisheries management also encounters challenges,which should be addressed in the process of exploration. China is an important fishing state at Antarctic O cean.Investigation for Antarctic fisheries resources and research into its exploitation are of significant importance for China,which calls for the establishment of China's Antarctic fisheries policy.展开更多
There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population r...There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population resources is increasing. This population is precious protein resource. It is urgent to study how to take prompt and effective fishing and take full advantage of processing,utilization and management. Traditional utilization methods are limited by many factors. The utilization efficiency is extremely low. The feed conversion rate of some mariculture fishes with fresh small trash fishes as feeds is even as low as 0. 2. Innovative production and management organization model with aquatic enterprises as leaders greatly increases the utilization efficiency of small fish resources with the aid of marine processing mother ship. In order to further accelerate developing and utilizing small fishery population resources in coastal and offshore areas,China should launch survey and utilization researches of small fishery population resources in coastal and offshore areas,formulate practical and feasible laws,regulations and policies,actively encourage and support autonomous innovative management mode of enterprises,and promote effective utilization and management of coastal and offshore fishery resources.展开更多
The off-shore demersal trap fishery in the southern Arabian Gulf has been managed by gear regulations and effort constraints which were aimed at rebuilding depleted stocks. In order to evaluate the success of these re...The off-shore demersal trap fishery in the southern Arabian Gulf has been managed by gear regulations and effort constraints which were aimed at rebuilding depleted stocks. In order to evaluate the success of these regulations, a variety of selectivity and other fishery metrics were compared for the key species (Diagramma pictum, Epinephelus coioides and Lethrinus nebulosus) before and after their introduction. With the exception of a minor increase in the mean age at first capture from 1.3 yrs to 1.9 yrs for E. coioides, there were no significant changes in the values or trends in juvenile retention, mean size or the mean sizes and ages at first capture. The comparison of selectivity ogives with data derived independently through an experimental fishing program indicated that the failure of juvenile escape panels to modify the selectivity characteristics of the fishery could not be attributed to a lack of compliance. Furthermore, there were no significant changes in fishing mortality rates, harvest rates, catch, effort, yield per recruit and relative spawner biomass per recruit following the introduction of the management regulations. Age structures were highly truncated and the management measures had failed to increase the relative proportion of older age classes. Stock status indicators suggested that all species were heavily over-exploited with evidence of both growth and recruitment over-fishing. Given the failure of existing regulations to modify gear selectivity, reduce effort and rebuild stocks, the results of the study suggest that management authorities should consider alternative measures including a moratorium on the use of traps in the off-shore demersal fishery of Abu Dhabi.展开更多
This report introduced new concept and technics for a grid-based fishery management system. The fishing ground was first divided into small grid of equal area, each with predefined longitudes and latitudes (both 0.033...This report introduced new concept and technics for a grid-based fishery management system. The fishing ground was first divided into small grid of equal area, each with predefined longitudes and latitudes (both 0.033 degrees or approximately 2 × 2 nautical miles in this study). All grids were laid and formatted into a Microsoft-Excel spreadsheet system, as defined by the coastline. Individual sheets were also constructed to represent different ecological characters, serving as supporting data of the main grid-map. Including individual fishing record, water depth, wind & current vector, benthic character, etc. Cellular automata (CA) mathematics was applied for simulation studies. They were programmed on the built-in Visual BASIC langrage in EXCEL. In a three-year research project, the author was able to accomplish the following major results: 1) An EXCEL-based spreadsheet system for storage of fishing effort in each grid. Provided that data of fishing yield is also available for each grid, research model for fishery management can be constructed, leading toward solutions for total allowable catch (TAC) as well as maximum economic yield (MEY). 2) A multi-layered, 2-dimentional spread-sheet system demonstrating the distribution of relative intensity for individual grids. The system can be decked up with different ecological data for more advanced studies. 3) Estimation of the nearest distance between two special grids as well as fishing harbors. This would help in more efficient navigation management and allocation of fishing rights for the fishing vessels.展开更多
Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made l...Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made lakes, Lake Ahozon and Lake Bewacodji of Southern Benin, with implications for species conservation, fisheries management and aquaculture valorization. From August 2014 to July 2015, habitats conditions were evaluated and fishes were sampled monthly with seine, cast net, experimental gill net and hooks in the open water and aquatic vegetation habitats of both lakes. Overall, the water quality of Lake Ahozon was globally favorable for the growth and the survival of the fish resources whereas Lake Bewacodji exhibited a poor water quality indicated mainly by an acid pH (mean: 6.32 ± 0.58) and low dissolved oxygen concentrations (mean: 3.52 ± 1.25 mg/l) caused by dense floating plants, Nymphea sp mainly and huge daily dumping of domestic wastes. The study revealed low species richness, d = 5.89 and d = 3.87, and low species diversity, H’ = 0.76 and H’ = 0.48 for Lakes Ahozon and Bewacodji, respectively, with Lake Ahozon more diverse than Lake Bewacodji. The fish community of Lake Ahozon comprised six (6) species, 3 cichlids Sarotherodon galilaeus, Oreochromis niloticus and Tilapia guineensis, the silver catfish, Chrysichthys nigrodigitatus (Claroteidae), the African bonytongue, Heterotis niloticus (Osteoglossidae), and the African catfish, Clarias gariepinus (Clariidae). Numerically, S. galilaeus dominated Lake Ahozon and made 85.21% of the sample. In Lake Bewacodji, the fish composition comprised four (4) species, Sarotherodon galilaeus multifasciatus, the dominant species making numerically 91.58% of the total sample, T. guineensis, C. gariepinus and C. nigrodigitatus. With regard to trophic structure, the fish assemblages of both lakes were numerically dominated by planktinovores/ detritivores, mainly S. galilaeus, O. niloticus, T. guineensis and C. nigrodigitatus making together 99.46% of Lake Ahozon fish community, and S. galilaeus multifasciatus, T. guineensis and C. nigrodigitatus accounting together for about 98.59% of Lake Bewacodji. In Lake Ahozon, standard length (SL) frequencies histograms showed an unimodal size distribution for H. niloticus, the nile tilapia O. niloticus and C. gariepinus whereas the two cichlids, S. galilaeus and T. guineensis exhibited a bimodal size distribution. In Lake Bewacodji, S. galilaeus multifasciatus, C. nigrodigitatus and C. gariepinus exhibited an unimodal size distribution. A sustainable exploitation of both man-made lakes requires the implementation of an integrated management scheme which should include habitat restoration and protection plan, fisheries/aquacultural valorization, ecological sound agriculture/ecotourism and environmental monitoring. 展开更多
Based on the local legislation of marine fishery management, this paper takes the process of local legislation of marine fishery management in Liaoning Province as the main object of study, to explore the advantages a...Based on the local legislation of marine fishery management, this paper takes the process of local legislation of marine fishery management in Liaoning Province as the main object of study, to explore the advantages and existing problems of the process of local marine fishery management. From the perspective of theory and practice, this paper analyzes the local legislative process deeply and discloses some problems, especially analyzes the main steps deeply in order to discover problems in the whole process from drafting to acting and proposes the corresponding solutions.展开更多
The distribution of lobsters in Indonesian waters is very wide,even lobster species in Indonesia are also scattered in the tropical waters of the western Pacific Ocean,the Indian Ocean,Africa to Japanese waters.Indone...The distribution of lobsters in Indonesian waters is very wide,even lobster species in Indonesia are also scattered in the tropical waters of the western Pacific Ocean,the Indian Ocean,Africa to Japanese waters.Indonesian waters are divided into 11(eleven)Fishery Management Zone(FMZ).Lobsters in Indonesia may come from various water areas,both national and regional water zones,and they’re called the sink population.Its spread is influenced by the movement of the current.Lobster seed is nurtured by nature through ocean currents from Australia,East Indonesia,Japan,then back to Australia.Lobsters have a complex life cycle,where adult lobsters inhabit coral reefs as a place to lay eggs,then hatch into planktonic larvae,and grow up in open seas and carry out diurnal and ontogenetic vertical migrations before returning to nurseries in shallow coastal areas and reefs,coral,as well as habitat by the type of species.Literature research had used at least two methodologies to estimate the distribution and connection sensitivity matrices of marine organism larvae.The two most common approaches are using genetic markers and numerical biophysical modeling.Thus,this research uses molecular genetic techniques to explain the genetic structure of lobster populations using a biophysical model approach that can explain the genetic structure of lobsters,as well as the distribution based on regional oceanographic synthesis data and lobster biology known in Indonesian waters.This model has four components,namely:1)a benthic module based on a Geographical Information System(GIS)which is a lobster habitat in the spawning and recruitment process,2)a physical oceanography module containing daily velocity in the form of a three-dimensional hydrodynamic model,3)a larva biology module that describes larval life history characteristics,and 4)a Lagrangian Stochastic module that tracks the individual trajectories of larvae.展开更多
This paper provides a critical review of some major efforts made by China to manage the fishing capacity of its marine capture fisheries. It begins by reviewing the key concepts and issues closely related to fishing c...This paper provides a critical review of some major efforts made by China to manage the fishing capacity of its marine capture fisheries. It begins by reviewing the key concepts and issues closely related to fishing capacity management. Following on this, a brief introduction to China’s marine capture fisheries is offered, especially the trends of its marine landings and marine fishing fleets and the status of fish stocks in waters under its jurisdiction. Next comes the main concern of the paper, i.e., some major actions recently initiated by China to deal with the overcapacity problem confronting it. The paper ends with conclusions and suggestions.展开更多
Natural mortality rate(M) is one of the essential parameters in fishery stock assessment, however, the estimation of M is commonly rough and the changes of M due to natural and anthropogenic impacts have long been i...Natural mortality rate(M) is one of the essential parameters in fishery stock assessment, however, the estimation of M is commonly rough and the changes of M due to natural and anthropogenic impacts have long been ignored.The simplification of M estimation and the influence of M variations on the assessment and management of fisheries stocks have been less well understood. This study evaluated the impacts of the changes in natural mortality of Spanish mackerel(Scomberomorus niphonius) on their management strategies with data-limited methods. We tested the performances of a variety of management procedures(MPs) with the variations of M in mackerel stock using diverse estimation methods. The results of management strategies evaluation showed that four management procedures DCAC, SPMSY, cur E75 and minlen Lopt1 were more robust to the changes of M than others; however, their performance were substantially influenced by the significant decrease of M from the 1970s to 2017. Relative population biomass(measure as the probability of B〉0.5 BMSY) increased significantly with the decrease of M, whereas the possibility of overfishing showed remarkable variations across MPs. The decrease of M had minor effects on the long-term yield of cur E75 and minlen Lopt1, and reduced the fluctuation of yield(measure as the probability of AAVY〈15%) for DCAC, SPMSY. In general, the different methods for M estimation showed minor effects on the performance of MPs, whereas the temporal changes of M showed substantial influences. Considering the fishery status of Spanish mackerel in China, we recommended that cur E75 has the best trade-off between fishery resources exploitation and conservation, and we also proposed the potentials and issues in their implementations.展开更多
The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing pr...The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing precautionary management strategies.We compare catch advice obtained from applications of various datalimited methods(DLMs)with forecasted catch advice from existing data-rich stock assessment models for the Indian Ocean bigeye tuna(Thunnus obesus).Our goal was to evaluate the consistency of catch advice derived from data-rich methods and data-limited approaches when only a subset of data is available.The Stock Synthesis(SS)results were treated as benchmarks for comparison because they reflect the most comprehensive and best possible scientific information of the stock.This study indicated that although the DLMs examined appeared robust for the Indian Ocean bigeye tuna,the implied catch advice differed between data-limited approaches and the current assessment,due to different data inputs and model assumptions.Most DLMs tended to provide more optimistic catch advice compared with the SS,which was mostly influenced by historical catches,current abundance and depletion estimates,and natural mortality,but was less sensitive to life-history parameters(particularly those related to growth).This study highlights the utility of DLMs and their implications on catch advice for the management of tuna stocks.展开更多
This article briefly reviewed the history of fishery resource management,especially the basic laws,concepts and basic techniques of aquatic resource management in Japan. It was concluded that the experience of managem...This article briefly reviewed the history of fishery resource management,especially the basic laws,concepts and basic techniques of aquatic resource management in Japan. It was concluded that the experience of management systems,basic methods,etc. in Japan,as a county that has earlier protected and managed aquatic resources,is worth learning by the establishment of China's aquatic resource management system.展开更多
Pseudotolithus typus is one of the two commercially important Sciaenids off Benin nearshore waters mainly fished by beach seining. Unfortunately, since 1994, the production of this species has been decreasing, and inc...Pseudotolithus typus is one of the two commercially important Sciaenids off Benin nearshore waters mainly fished by beach seining. Unfortunately, since 1994, the production of this species has been decreasing, and increasingly more small-sized fishes are regularly harvested, while little is known about the species’ population structure and its life history. Therefore, population structure, probability of capture and size at first capture were investigated using length-frequency data of 1144 specimens sampled from beach seine hauls over a period of 18 months. A total of 54.3% of this population was immature, confirming the domination of smallsized fishes in the catches. Gonad maturation stages were also examined. Frequency distribution of oocyte size exhibited two cohorts of mature oocytes suggesting two spawning periods per year. Monthly averages of gonado-somatic index confirmed that P. typus spawned twice a year during the major warm season (March - May) and during the transition minor warm to minor cold season in October - November. Length at first capture (L75 = 22.76 cm) was smaller than the length at first sexual maturation (L50% = 23.6 cm) indicating a heavy pressure of the beach seine on this resource. To give each fish the chance of reproducing at least once in its lifetime to recruit into the stock, necessary measures such as the size-limit regulation by gradually increasing beach seine mesh size should be developed. Community-based management of the nearshore fishery could contribute to reducing fishing effort during the reproductive periods from February to May and from October to December each year.展开更多
Conflicts among different fisher groups are a global concern, and the Okavango Delta fishery is no exception, which is composed of commercial, subsistence and recreational fishers. Possibly due to conflicting value/us...Conflicts among different fisher groups are a global concern, and the Okavango Delta fishery is no exception, which is composed of commercial, subsistence and recreational fishers. Possibly due to conflicting value/use systems, and ill-defined user rights, there have been documented cases of conflict between commercial and recreational fishers, which may affect livelihoods for local fishers. Therefore, this study’s aim was to identify causes of conflict between these groups and to propose management inventions. Primary data collected in three fishing villages showed that lack of access, misconceptions about each other, and overlapping use were identified as some of the major causes of conflict. Subsequently, this paper proposes a spatial and temporal zoning of fishing grounds as a management tool towards conflict resolution. One proposal is that recreational fishers can utilize the main channel, commercial fishers the floodplains and lagoons, while basket fishers can utilize the fringes of floodplains, lagoons and river channel. Moreover, a co-management regime has also been developed in the fishery, upon which a code of conduct was developed to also reduce conflict in the fishery. It is envisaged that this approach will reduce conflict and create an enabling environment for efficient and sustainable fish utilization in the Delta.展开更多
A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitat...A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitats. Many of these environments are in decline due to changes in ecosystem structure and function resulting from multiple stressor effects. In addition, inadequate governance has supported a patchwork of single issues or sectoral approaches rather than integrated management of multiple human uses and activities to maintain healthy, productive, resilient, and sustainable ecosystems and the provision of goods and services. Ecosystem-based marine spatial planning is a viable framework for a more effective governance structure and management of these vital coastal environments. An important component of this approach is a holistic effort to assess the environmental, economic, and societal impacts of anthropogenic activities. Thus, a multidisciplinary integrated approach is preferred that links ecological, physical, and socio-economic systems, increasing the protection of resources and societal benefits. For degraded estuarine and coastal marine ecosystems, restoration and rehabilitation initiatives are important intervention strategies used to reverse the loss of habitats and biotic resources and to support management programs. Marine Protected Areas (MPAs) are an integral element of marine management plans to conserve and sustain estuarine and coastal marine environments by protecting threatened ecosystems and their resources from anthropogenic activities. National and international regulatory frameworks and directives are also in place to protect and conserve these environments.展开更多
In order to develop a method that apply sampling survey data randomly obtained at fishing ports to fish stock assessments,based on fish landing surveys conducted at fishing ports in the northern South China Sea(SCS),1...In order to develop a method that apply sampling survey data randomly obtained at fishing ports to fish stock assessments,based on fish landing surveys conducted at fishing ports in the northern South China Sea(SCS),19 Threadfin porgy(Evynnis cardinalis)catch per unit effort(CPUE)datasets were collected for fishing vessels with different gear types and engine powers and incorporated into surplus production models.Considering only the fitting performance,the Schaefer model had the best overall goodness of fit,followed by the Fox,CYP,W-H,and Schnute models.Among fishing vessels with different gears and engine powers,the data were best fitted for single-trawl vessels powered by 301-400-kW engines and for gillnet vessels powered by>200-kW engines.Eight model expressions were superior and selected for subsequent analyses based on their goodness of fit and relative residuals.The Kobe plot analysis results showed an optimistic fish stock status when using the four model expressions,required more caution when using three model expressions and output pessimistic estimations using one model expression.Considering the incomplete information acquired,a compromising decision-making method was used to derive a 2017 northern SCS E.cardinalis total allowed catch(TAC)of 44,691.21 t.The different conclusions drawn from estimations using CPUEs reflect variable exploitation and utilization fish stock statuses among fishing vessels with different gears and engine powers.Hence,the fishing operations were grouped according to their CPUE relationship,and recommendations regarding optimum fishing efforts were assigned to the groups following a fundamental principle:to improve fishery TAC management,fishing efforts should be reduced if the fish stock assessment is pessimistic and maintained if the assessment is optimistic.This study providing a feasible technical method for the TAC management of China’s offshore fisheries.展开更多
Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently...Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on GIS (geographical information system)to deal with the marine information. The GIS has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the GIS systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional GIS and its data structure. This work designed a data model, the raster-based spatio-temporal hierarchical data model (RSHDM), for the marine information system, or for the knowledge discovery fi'om spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse (FDW) for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels.展开更多
The stock of Bigeye tuna(Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission(IOT...The stock of Bigeye tuna(Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission(IOTC), does not have an explicit management decision-making framework in place to prevent over-fishing. In this study, we evaluated three harvest control rules, i) constant fishing mortality(CF), from 0.2 to 0.6, ii) constant catch(CC), from 60000 to 140000 t, and iii) constant escapement(CE), from 0.3 to 0.7. The population dynamics simulated by the operating model was based on the most recent stock assessment using Stock Synthesis version Ⅲ(SS3). Three simulation scenarios(low, medium and high productivity) were designed to cover possible uncertainty in the stock assessment and biological parameters. Performances of three harvest control rules were compared on the basis of three management objectives(over 3, 10 and 25 years): i) the probability of maintaining spawning stock biomass above a level that can sustain maximum sustainable yield(MSY) on average, ii) the probability of achieving average catches between 0.8 MSY and 1.0 MSY, and iii) inter-annual variability in catches. The constant escapement strategy(CE=0.5), constant fishing mortality strategy(F=0.4) and constant catch(CC=80000) were the most rational among the respective management scenarios. It is concluded that the short-term annual catch is suggested at 80000 t, and the potential total allowable catch for a stable yield could be set at 120000 t once the stock had recovered successfully. All the strategies considered in this study to achieve a ‘tolerable' balance between resource conservation and utilization have been based around the management objectives of the IOTC.展开更多
文摘We have analyzed the development of “Broad-Scale Seabed Habitat Maps” (BSHM) and their potential use in a European context with regard to the EU Marine Strategy Framework Directive (MSFD) implementation, MPA designation and network assessment as well as other applications of BSHMs. The analyses are anchored in BSHMs developed by a series of interlinked EU projects (e.g. UKSeaMap, BALANCE, MESH, Mesh Atlantic, EUSeaMap 2012, and EUSeaMap 2016) and all maps are based on environmental data. Some EU Member States have used BSHMs as part of their MSFD Initial Assessments published in 2012. However, we conclude that BSHMs are a prerequisite for another key MSFD activity, i.e. mapping of potentially cumulative effects of multiple human stressors. Further, BSHMs seem to play a growing role with regard to evidence-based assessments of MPAs. With the upcoming second round of MSFD Initial Assessments due in 2018, including assessment of potentially cumulative pressures, there seems to be an increasing need for more BSHMs nationally, regionally and on a European scale.
文摘Functional genes and gene expression have been connected to physiological traits linked to effective production and broodstock selection in aquaculture, selective implications of commercial fish harvest, and adaptive changes reflected in non-commercial fish populations subject to human disturbance and climate change. Gene mapping using single nucleotide polymorphisms (SNPs) to identify functional genes, gene expression (analogue microarrays and real-time PCR), and digital sequencing technologies looking at RNA transcripts present new concepts and opportunities in support of effective and sustainable fisheries. Genomic tools have been rapidly growing in aquaculture research addressing aspects of fish health, toxicology, and early development. Genomic technologies linking effects in functional genes involved in growth, maturation and life history development have been tied to selection resulting from harvest practices. Incorporating new and ever-increasing knowledge of fish gehomes is opening a different perspective on local adaptation that will prove invaluable in wild fish conservation and management. Conservation of fish stocks is rapidly incorporating research on critical adaptive responses directed at the effects of human dis- turbance and climate change through gene expression studies. Genomic studies of fish populations can be generally grouped into three broad categories: l) evolutionary genomics and biodiversity; 2) adaptive physiological responses to a changing environment; and 3) adaptive behavioral genomics and life history diversity. We review current genomic research in fisheries focusing on those that use microarrays to explore differences in gene expression among phenotypes and within or across populations, information that is critically important to the conservation of fish and their relationship to humans [Current Zoology 56 (1): 157-174, 2010].
文摘This paper exemplifies a primary step towards eliciting primary and secondary stakeholders’ views on management issues pertaining to kingfish fishery in Oman, and potential options for effective management of the fishery using questionnaire surveys and focus group interviews. There was consensus from stakeholder groups which included fishers, fishery managers, and fishery scientists that the current stock condition is not biologically sustainable. It is found that fishing effort control and technical measures are preferred to catch control by both groups. The role of mass media and the traditional institution in communicating fisheries issues are found to be relatively minor. Although the overall rating on the comprehensiveness of the proposed plan is promising, there are significant differences between the two groups with regard to legislative arrangements (χ<sup>2</sup> = 24.793, p-value = 0.000), management goals (χ<sup>2</sup> = 16.206, p-value = 0.001), operational objectives (χ<sup>2</sup> = 19.884, p-value = 0.000), performance indicators (χ<sup>2</sup> = 15.524, p-value = 0.001), and measures (χ<sup>2</sup> = 13.483, p-value = 0.004). Policy implications of the key findings are discussed in both national and regional contexts. Management authorities can use these findings to design an appropriate plan of actions for achieving sustainability in this fishery.
基金This paper is supported by China’s National Social Science Foundation entitled“Research on China’s Policy on Antarctic Krill Fishery”(17BGJ014),“Safeguard of National Marine Rights and Interests”(17VHQ010)and Japan Society for the Promoting of Science Int
文摘Commission for the Conservation of Antarctic Marine Living R esources acts as the executive body for Antarctic fisheries management with Convention on the Conservation of Antarctic Marine Living R esources( CAMLR Convention) as the legal framework. As the only multilateral agreement for the comprehensive management of Antarctic marine living resources,CAMLR Convention has received a wide international recognition. This paper analyzes the highlights of CAMLR Convention in Antarctic fisheries management,namely,open access to membership,sophisticated institutional structure,capability of keeping pace with the times,diplomatic wisdom,measures against IU U,advanced fisheries management philosophies,etc. Meanwhile,Antarctic fisheries management also encounters challenges,which should be addressed in the process of exploration. China is an important fishing state at Antarctic O cean.Investigation for Antarctic fisheries resources and research into its exploitation are of significant importance for China,which calls for the establishment of China's Antarctic fisheries policy.
文摘There are numerous types of living resources in coastal and offshore areas of China. In recent years,both the population type and quantity structure have significant changes,and the stock of small fishery population resources is increasing. This population is precious protein resource. It is urgent to study how to take prompt and effective fishing and take full advantage of processing,utilization and management. Traditional utilization methods are limited by many factors. The utilization efficiency is extremely low. The feed conversion rate of some mariculture fishes with fresh small trash fishes as feeds is even as low as 0. 2. Innovative production and management organization model with aquatic enterprises as leaders greatly increases the utilization efficiency of small fish resources with the aid of marine processing mother ship. In order to further accelerate developing and utilizing small fishery population resources in coastal and offshore areas,China should launch survey and utilization researches of small fishery population resources in coastal and offshore areas,formulate practical and feasible laws,regulations and policies,actively encourage and support autonomous innovative management mode of enterprises,and promote effective utilization and management of coastal and offshore fishery resources.
文摘The off-shore demersal trap fishery in the southern Arabian Gulf has been managed by gear regulations and effort constraints which were aimed at rebuilding depleted stocks. In order to evaluate the success of these regulations, a variety of selectivity and other fishery metrics were compared for the key species (Diagramma pictum, Epinephelus coioides and Lethrinus nebulosus) before and after their introduction. With the exception of a minor increase in the mean age at first capture from 1.3 yrs to 1.9 yrs for E. coioides, there were no significant changes in the values or trends in juvenile retention, mean size or the mean sizes and ages at first capture. The comparison of selectivity ogives with data derived independently through an experimental fishing program indicated that the failure of juvenile escape panels to modify the selectivity characteristics of the fishery could not be attributed to a lack of compliance. Furthermore, there were no significant changes in fishing mortality rates, harvest rates, catch, effort, yield per recruit and relative spawner biomass per recruit following the introduction of the management regulations. Age structures were highly truncated and the management measures had failed to increase the relative proportion of older age classes. Stock status indicators suggested that all species were heavily over-exploited with evidence of both growth and recruitment over-fishing. Given the failure of existing regulations to modify gear selectivity, reduce effort and rebuild stocks, the results of the study suggest that management authorities should consider alternative measures including a moratorium on the use of traps in the off-shore demersal fishery of Abu Dhabi.
文摘This report introduced new concept and technics for a grid-based fishery management system. The fishing ground was first divided into small grid of equal area, each with predefined longitudes and latitudes (both 0.033 degrees or approximately 2 × 2 nautical miles in this study). All grids were laid and formatted into a Microsoft-Excel spreadsheet system, as defined by the coastline. Individual sheets were also constructed to represent different ecological characters, serving as supporting data of the main grid-map. Including individual fishing record, water depth, wind & current vector, benthic character, etc. Cellular automata (CA) mathematics was applied for simulation studies. They were programmed on the built-in Visual BASIC langrage in EXCEL. In a three-year research project, the author was able to accomplish the following major results: 1) An EXCEL-based spreadsheet system for storage of fishing effort in each grid. Provided that data of fishing yield is also available for each grid, research model for fishery management can be constructed, leading toward solutions for total allowable catch (TAC) as well as maximum economic yield (MEY). 2) A multi-layered, 2-dimentional spread-sheet system demonstrating the distribution of relative intensity for individual grids. The system can be decked up with different ecological data for more advanced studies. 3) Estimation of the nearest distance between two special grids as well as fishing harbors. This would help in more efficient navigation management and allocation of fishing rights for the fishing vessels.
文摘Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made lakes, Lake Ahozon and Lake Bewacodji of Southern Benin, with implications for species conservation, fisheries management and aquaculture valorization. From August 2014 to July 2015, habitats conditions were evaluated and fishes were sampled monthly with seine, cast net, experimental gill net and hooks in the open water and aquatic vegetation habitats of both lakes. Overall, the water quality of Lake Ahozon was globally favorable for the growth and the survival of the fish resources whereas Lake Bewacodji exhibited a poor water quality indicated mainly by an acid pH (mean: 6.32 ± 0.58) and low dissolved oxygen concentrations (mean: 3.52 ± 1.25 mg/l) caused by dense floating plants, Nymphea sp mainly and huge daily dumping of domestic wastes. The study revealed low species richness, d = 5.89 and d = 3.87, and low species diversity, H’ = 0.76 and H’ = 0.48 for Lakes Ahozon and Bewacodji, respectively, with Lake Ahozon more diverse than Lake Bewacodji. The fish community of Lake Ahozon comprised six (6) species, 3 cichlids Sarotherodon galilaeus, Oreochromis niloticus and Tilapia guineensis, the silver catfish, Chrysichthys nigrodigitatus (Claroteidae), the African bonytongue, Heterotis niloticus (Osteoglossidae), and the African catfish, Clarias gariepinus (Clariidae). Numerically, S. galilaeus dominated Lake Ahozon and made 85.21% of the sample. In Lake Bewacodji, the fish composition comprised four (4) species, Sarotherodon galilaeus multifasciatus, the dominant species making numerically 91.58% of the total sample, T. guineensis, C. gariepinus and C. nigrodigitatus. With regard to trophic structure, the fish assemblages of both lakes were numerically dominated by planktinovores/ detritivores, mainly S. galilaeus, O. niloticus, T. guineensis and C. nigrodigitatus making together 99.46% of Lake Ahozon fish community, and S. galilaeus multifasciatus, T. guineensis and C. nigrodigitatus accounting together for about 98.59% of Lake Bewacodji. In Lake Ahozon, standard length (SL) frequencies histograms showed an unimodal size distribution for H. niloticus, the nile tilapia O. niloticus and C. gariepinus whereas the two cichlids, S. galilaeus and T. guineensis exhibited a bimodal size distribution. In Lake Bewacodji, S. galilaeus multifasciatus, C. nigrodigitatus and C. gariepinus exhibited an unimodal size distribution. A sustainable exploitation of both man-made lakes requires the implementation of an integrated management scheme which should include habitat restoration and protection plan, fisheries/aquacultural valorization, ecological sound agriculture/ecotourism and environmental monitoring.
文摘Based on the local legislation of marine fishery management, this paper takes the process of local legislation of marine fishery management in Liaoning Province as the main object of study, to explore the advantages and existing problems of the process of local marine fishery management. From the perspective of theory and practice, this paper analyzes the local legislative process deeply and discloses some problems, especially analyzes the main steps deeply in order to discover problems in the whole process from drafting to acting and proposes the corresponding solutions.
文摘The distribution of lobsters in Indonesian waters is very wide,even lobster species in Indonesia are also scattered in the tropical waters of the western Pacific Ocean,the Indian Ocean,Africa to Japanese waters.Indonesian waters are divided into 11(eleven)Fishery Management Zone(FMZ).Lobsters in Indonesia may come from various water areas,both national and regional water zones,and they’re called the sink population.Its spread is influenced by the movement of the current.Lobster seed is nurtured by nature through ocean currents from Australia,East Indonesia,Japan,then back to Australia.Lobsters have a complex life cycle,where adult lobsters inhabit coral reefs as a place to lay eggs,then hatch into planktonic larvae,and grow up in open seas and carry out diurnal and ontogenetic vertical migrations before returning to nurseries in shallow coastal areas and reefs,coral,as well as habitat by the type of species.Literature research had used at least two methodologies to estimate the distribution and connection sensitivity matrices of marine organism larvae.The two most common approaches are using genetic markers and numerical biophysical modeling.Thus,this research uses molecular genetic techniques to explain the genetic structure of lobster populations using a biophysical model approach that can explain the genetic structure of lobsters,as well as the distribution based on regional oceanographic synthesis data and lobster biology known in Indonesian waters.This model has four components,namely:1)a benthic module based on a Geographical Information System(GIS)which is a lobster habitat in the spawning and recruitment process,2)a physical oceanography module containing daily velocity in the form of a three-dimensional hydrodynamic model,3)a larva biology module that describes larval life history characteristics,and 4)a Lagrangian Stochastic module that tracks the individual trajectories of larvae.
文摘This paper provides a critical review of some major efforts made by China to manage the fishing capacity of its marine capture fisheries. It begins by reviewing the key concepts and issues closely related to fishing capacity management. Following on this, a brief introduction to China’s marine capture fisheries is offered, especially the trends of its marine landings and marine fishing fleets and the status of fish stocks in waters under its jurisdiction. Next comes the main concern of the paper, i.e., some major actions recently initiated by China to deal with the overcapacity problem confronting it. The paper ends with conclusions and suggestions.
基金The Fundamental Research Funds for the Central Universities under contract Nos 201562030 and 201612004
文摘Natural mortality rate(M) is one of the essential parameters in fishery stock assessment, however, the estimation of M is commonly rough and the changes of M due to natural and anthropogenic impacts have long been ignored.The simplification of M estimation and the influence of M variations on the assessment and management of fisheries stocks have been less well understood. This study evaluated the impacts of the changes in natural mortality of Spanish mackerel(Scomberomorus niphonius) on their management strategies with data-limited methods. We tested the performances of a variety of management procedures(MPs) with the variations of M in mackerel stock using diverse estimation methods. The results of management strategies evaluation showed that four management procedures DCAC, SPMSY, cur E75 and minlen Lopt1 were more robust to the changes of M than others; however, their performance were substantially influenced by the significant decrease of M from the 1970s to 2017. Relative population biomass(measure as the probability of B〉0.5 BMSY) increased significantly with the decrease of M, whereas the possibility of overfishing showed remarkable variations across MPs. The decrease of M had minor effects on the long-term yield of cur E75 and minlen Lopt1, and reduced the fluctuation of yield(measure as the probability of AAVY〈15%) for DCAC, SPMSY. In general, the different methods for M estimation showed minor effects on the performance of MPs, whereas the temporal changes of M showed substantial influences. Considering the fishery status of Spanish mackerel in China, we recommended that cur E75 has the best trade-off between fishery resources exploitation and conservation, and we also proposed the potentials and issues in their implementations.
基金The National Natural Science Foundation of China under contract No.41676120。
文摘The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing precautionary management strategies.We compare catch advice obtained from applications of various datalimited methods(DLMs)with forecasted catch advice from existing data-rich stock assessment models for the Indian Ocean bigeye tuna(Thunnus obesus).Our goal was to evaluate the consistency of catch advice derived from data-rich methods and data-limited approaches when only a subset of data is available.The Stock Synthesis(SS)results were treated as benchmarks for comparison because they reflect the most comprehensive and best possible scientific information of the stock.This study indicated that although the DLMs examined appeared robust for the Indian Ocean bigeye tuna,the implied catch advice differed between data-limited approaches and the current assessment,due to different data inputs and model assumptions.Most DLMs tended to provide more optimistic catch advice compared with the SS,which was mostly influenced by historical catches,current abundance and depletion estimates,and natural mortality,but was less sensitive to life-history parameters(particularly those related to growth).This study highlights the utility of DLMs and their implications on catch advice for the management of tuna stocks.
文摘This article briefly reviewed the history of fishery resource management,especially the basic laws,concepts and basic techniques of aquatic resource management in Japan. It was concluded that the experience of management systems,basic methods,etc. in Japan,as a county that has earlier protected and managed aquatic resources,is worth learning by the establishment of China's aquatic resource management system.
文摘Pseudotolithus typus is one of the two commercially important Sciaenids off Benin nearshore waters mainly fished by beach seining. Unfortunately, since 1994, the production of this species has been decreasing, and increasingly more small-sized fishes are regularly harvested, while little is known about the species’ population structure and its life history. Therefore, population structure, probability of capture and size at first capture were investigated using length-frequency data of 1144 specimens sampled from beach seine hauls over a period of 18 months. A total of 54.3% of this population was immature, confirming the domination of smallsized fishes in the catches. Gonad maturation stages were also examined. Frequency distribution of oocyte size exhibited two cohorts of mature oocytes suggesting two spawning periods per year. Monthly averages of gonado-somatic index confirmed that P. typus spawned twice a year during the major warm season (March - May) and during the transition minor warm to minor cold season in October - November. Length at first capture (L75 = 22.76 cm) was smaller than the length at first sexual maturation (L50% = 23.6 cm) indicating a heavy pressure of the beach seine on this resource. To give each fish the chance of reproducing at least once in its lifetime to recruit into the stock, necessary measures such as the size-limit regulation by gradually increasing beach seine mesh size should be developed. Community-based management of the nearshore fishery could contribute to reducing fishing effort during the reproductive periods from February to May and from October to December each year.
文摘Conflicts among different fisher groups are a global concern, and the Okavango Delta fishery is no exception, which is composed of commercial, subsistence and recreational fishers. Possibly due to conflicting value/use systems, and ill-defined user rights, there have been documented cases of conflict between commercial and recreational fishers, which may affect livelihoods for local fishers. Therefore, this study’s aim was to identify causes of conflict between these groups and to propose management inventions. Primary data collected in three fishing villages showed that lack of access, misconceptions about each other, and overlapping use were identified as some of the major causes of conflict. Subsequently, this paper proposes a spatial and temporal zoning of fishing grounds as a management tool towards conflict resolution. One proposal is that recreational fishers can utilize the main channel, commercial fishers the floodplains and lagoons, while basket fishers can utilize the fringes of floodplains, lagoons and river channel. Moreover, a co-management regime has also been developed in the fishery, upon which a code of conduct was developed to also reduce conflict in the fishery. It is envisaged that this approach will reduce conflict and create an enabling environment for efficient and sustainable fish utilization in the Delta.
文摘A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitats. Many of these environments are in decline due to changes in ecosystem structure and function resulting from multiple stressor effects. In addition, inadequate governance has supported a patchwork of single issues or sectoral approaches rather than integrated management of multiple human uses and activities to maintain healthy, productive, resilient, and sustainable ecosystems and the provision of goods and services. Ecosystem-based marine spatial planning is a viable framework for a more effective governance structure and management of these vital coastal environments. An important component of this approach is a holistic effort to assess the environmental, economic, and societal impacts of anthropogenic activities. Thus, a multidisciplinary integrated approach is preferred that links ecological, physical, and socio-economic systems, increasing the protection of resources and societal benefits. For degraded estuarine and coastal marine ecosystems, restoration and rehabilitation initiatives are important intervention strategies used to reverse the loss of habitats and biotic resources and to support management programs. Marine Protected Areas (MPAs) are an integral element of marine management plans to conserve and sustain estuarine and coastal marine environments by protecting threatened ecosystems and their resources from anthropogenic activities. National and international regulatory frameworks and directives are also in place to protect and conserve these environments.
基金supported by the National Key R&D Program of China(2018YFD0900906)the Guangdong Natural Science Foundation(2016A030313752)+1 种基金the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(ZJW-2019-08)the Scientific Research Foundation for Talent Introduction,Guangdong Ocean University(1212037).
文摘In order to develop a method that apply sampling survey data randomly obtained at fishing ports to fish stock assessments,based on fish landing surveys conducted at fishing ports in the northern South China Sea(SCS),19 Threadfin porgy(Evynnis cardinalis)catch per unit effort(CPUE)datasets were collected for fishing vessels with different gear types and engine powers and incorporated into surplus production models.Considering only the fitting performance,the Schaefer model had the best overall goodness of fit,followed by the Fox,CYP,W-H,and Schnute models.Among fishing vessels with different gears and engine powers,the data were best fitted for single-trawl vessels powered by 301-400-kW engines and for gillnet vessels powered by>200-kW engines.Eight model expressions were superior and selected for subsequent analyses based on their goodness of fit and relative residuals.The Kobe plot analysis results showed an optimistic fish stock status when using the four model expressions,required more caution when using three model expressions and output pessimistic estimations using one model expression.Considering the incomplete information acquired,a compromising decision-making method was used to derive a 2017 northern SCS E.cardinalis total allowed catch(TAC)of 44,691.21 t.The different conclusions drawn from estimations using CPUEs reflect variable exploitation and utilization fish stock statuses among fishing vessels with different gears and engine powers.Hence,the fishing operations were grouped according to their CPUE relationship,and recommendations regarding optimum fishing efforts were assigned to the groups following a fundamental principle:to improve fishery TAC management,fishing efforts should be reduced if the fish stock assessment is pessimistic and maintained if the assessment is optimistic.This study providing a feasible technical method for the TAC management of China’s offshore fisheries.
基金supported by the National Key Basic Research and Development Program of China under contract No.2006CB701305the National Natural Science Foundation of China under coutract No.40571129the National High-Technology Program of China under contract Nos 2002AA639400,2003AA604040 and 2003AA637030.
文摘Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on GIS (geographical information system)to deal with the marine information. The GIS has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the GIS systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional GIS and its data structure. This work designed a data model, the raster-based spatio-temporal hierarchical data model (RSHDM), for the marine information system, or for the knowledge discovery fi'om spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse (FDW) for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels.
基金supported by Shanghai Ocean University Graduate School (PhD Dissertation Grant)the National High-tech R&D Program of China (863 Program 2012AA 092303)+3 种基金Project of Shanghai Science and Technology Innovation (12231203900)Industrialization Program of National Development and Reform Commission (2159999)National Key Technologies Research, Development Program of China (2013BAD13B00)Shanghai Universities First-Class Disciplines Project (Fisheries A)
文摘The stock of Bigeye tuna(Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission(IOTC), does not have an explicit management decision-making framework in place to prevent over-fishing. In this study, we evaluated three harvest control rules, i) constant fishing mortality(CF), from 0.2 to 0.6, ii) constant catch(CC), from 60000 to 140000 t, and iii) constant escapement(CE), from 0.3 to 0.7. The population dynamics simulated by the operating model was based on the most recent stock assessment using Stock Synthesis version Ⅲ(SS3). Three simulation scenarios(low, medium and high productivity) were designed to cover possible uncertainty in the stock assessment and biological parameters. Performances of three harvest control rules were compared on the basis of three management objectives(over 3, 10 and 25 years): i) the probability of maintaining spawning stock biomass above a level that can sustain maximum sustainable yield(MSY) on average, ii) the probability of achieving average catches between 0.8 MSY and 1.0 MSY, and iii) inter-annual variability in catches. The constant escapement strategy(CE=0.5), constant fishing mortality strategy(F=0.4) and constant catch(CC=80000) were the most rational among the respective management scenarios. It is concluded that the short-term annual catch is suggested at 80000 t, and the potential total allowable catch for a stable yield could be set at 120000 t once the stock had recovered successfully. All the strategies considered in this study to achieve a ‘tolerable' balance between resource conservation and utilization have been based around the management objectives of the IOTC.