Overfishing in the Gulf of Thailand: policy challenges and bioeconomic analysis

2007 ◽  
Vol 12 (1) ◽  
pp. 145-172 ◽  
Author(s):  
MAHFUZUDDIN AHMED ◽  
PONGPAT BOONCHUWONGSE ◽  
WARAPORN DECHBOON ◽  
DALE SQUIRES

This paper estimates maximum sustainable yield and maximum economic yield from Schaefer and Fox surplus production bioeconomic models to find evidence of biological and economic overfishing, and their consequences in Gulf of Thailand demersal fisheries. The paper examines alternative policy instruments to reduce overfishing. The discussion emphasizes strengthening fishery management for implementing limited access, and a combination of co-management, and decentralization of fisheries management. The use of license fees that serves as a double dividend tax to reduce fishing effort and fund monitoring and enforcement has been proposed as one of the possible economic instruments.

2009 ◽  
Vol 6 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Henrik Sparholt ◽  
Robin M. Cook

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.


Author(s):  
Rizky Ferawati ◽  
Zuzy Anna ◽  
Iwang Gumilar ◽  
Achmad Rizal

Long jawed mackerel resources are resources that are open access and common resources. The activity of catch mackerel in Indramayu district is increasing every year. In 2018 total fish production was 8423 tons while in 2019 there were 9047 tons. The utilization of long jawed mackerel resources must be based on economic and biological aspects as well as planning a sustainable use of long jawed mackerel. This study aims to analyze the conditions, efforts, and actual production of bloating fishing activities that are sustainable and optimal in Indramayu, as well as providing input into the direction of appropriate input and output management in bloating fishing activities in Indramayu Regency. The study was conducted in December 2019 to January 2020. The method used in this study was a survey method using quantitative descriptive analysis. Sample included 100 patients (age range 15-65 years) with respondents were owner fishermen, crew members, and/or boat captains, respondents were fishing using payang and purse seine. The data analysis method used is Gordon Schaefer's bioeconomic analysis. The results of the study found that the recommended fishing effort was in Maximum Sustainable Yield (MSY) 100.061 trip conditions and total production of 9011 tons, Maximum Economic Yield (MEY) conditions 98.756 trips and total production of 9.009 tons, and Open Access (OA) conditions in 197.513 trips and total production of 4.638 tons. The condition of long jawed mackerel in Indramayu Regency has experienced biological overfishing and economical overfishing. The policy recommendation is a limited entry of 27.242 trips (MSY) to 28.547 trips (MEY). Presentation of the reduction in the number of payang and purse seine fishing gear fleets under the conditions of MSY was 58% and 91,3% while for the MEY conditions were 59% and 91,7%.


Author(s):  
Muhammad Jamal Alwi ◽  
Hasrun Abdullah ◽  
Ernaningsih Aras

Skipjack tuna (Katsuwonus pelamis), should be managed properly because even though it is renewable, natural resources can be depleted. One approach in managing fish resources is by modeling. The purpose of this study is to determine the maximum sustainable yield, the level of utilization and effort of skipjack tuna. Data on catches as well as catch efforts of skipjack tuna were collected from 9 fisheries year books of Luwu Kabupaten (District). The surplus production model used is the Schaefer, Fox, Walter & Hilborn model. Schaefer model obtained by MSY = 1541.08 tons and Fopt = 243 trips; Fox model obtained maximum sustainable yield value (YMSY) of 1602,244 tons, maximum sustainable fishing effort (fMSY) of 303 units and maximum sustainable CpUE value (UMSY) of 5.29 tons trip-1; the Walter & Hilborn model found potential stocks of sustainable reserves (Be) skipjack in Luwu district amounted to 935.72 tons year-1. Utilization rates of the skpjack tuina indicate the fish is still under exploitation.


2019 ◽  
Vol 76 (10) ◽  
pp. 1885-1893 ◽  
Author(s):  
Ledhyane Ika Harlyan ◽  
Dengke Wu ◽  
Ryosuke Kinashi ◽  
Methee Kaewnern ◽  
Takashi Matsuishi

Harvest control rules (HCRs) for sustainable fishery management have been developed for data-limited fish species for which stock assessments cannot be conducted. However, HCRs have largely not considered mixed-species catches, as when fishing-effort data are widely pooled for numerous minor species in a multispecies fishery. Presently, a feedback HCR has been successfully applied in Japanese fisheries management. By combining management strategy evaluation with a simulation to generate mixed-species data from a multispecies fishery that assume constant catchability (q) among species, we evaluated the performance of this feedback HCR and then compared its performance using species-specific data. In most cases, the biomass was controlled over that needed for maximum sustainable yield (MSY), and the fishing effort was under the fishing mortality consistent with achieving MSY (FMSY). However, for slow-growing species, the biomass might become lower than what is required to remain capable of producing MSY, even though fishing effort was controlled under FMSY. The results show that the feedback HCR is appropriate for multispecies fisheries management where only mixed-species data are available but with special monitoring for slow-growing minor species.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ahasan Habib ◽  
Md. Hadayet Ullah ◽  
Nguyen Ngoc Duy

The fishery of the Bay of Bengal (BOB) is assumed to be suffering from the overexploitation. This paper aims to assess the sustainability of current level of fishing effort as well as possible changes driven by anthropogenic and climate driven factors. Therefore, the commercial marine fishery of BOB for the period of 1985/86 to 2007/08 is analyzed by applying Gordon-Schaefer Surplus Production Model on time series of total catch and standardized effort. Static reference points such as open-access equilibrium, maximum economic yield, and maximum sustainable yield are established. Assumptions about potential climatic and anthropogenic effects on r (intrinsic growth rate) and K (carrying capacity) of BOB fishery have been made under three different reference equilibriums. The results showed that the fishery is not biologically overexploited; however, it is predicted to be passing a critical situation, in terms of achieving reference points in the near future. But, on the other hand, economic overfishing started several years before. Higher fishing effort, and inadequate institutional and legal framework have been the major bottlenecks for the proper management of BOB fisheries and these may leads fishery more vulnerable against changing marine realm. Thus, the present study calls for policy intervention to rescue the stock from the existing high fishing pressure that would lead to depletion.


2017 ◽  
Vol 6 (1) ◽  
pp. 21
Author(s):  
David Y Rumambi ◽  
Unstain N. W. J. Rembet ◽  
Joudy R. R. Sangari

This research activity took place in Manado City, North Sulawesi Province with activities centered on the Tumumpa Fishery Harbor (PPP). The data were recorded from capture fisheries activity conducted in the Sulawesi Sea and its surroundings landed in the Tumumpa Fishery Harbor. The purpose of this study was to analyze the stock value and Maximum Sustainable Yield (MSY) of pelagic fish in the Sulawesi Sea based on the approach of the surplus production model (Model Schaefer). This research is expected to be used as a consideration in the management of pelagic fish stocks in the Sulawesi Sea, and can be used as a basis for further research. This research uses secondary data collection method in the form of statistical document and record available. The data taken, including fish catch and fishing effort or effort (trip), from 2012 to 2016 (5 years). The results show that production value is inversely proportional to the value of effort, where the value of production from 2012 to 2016 has decreased every year, while the value of effort from 2012 to 2016 has increased. This condition indicates that the presence of pelagic fish stocks in the Sulawesi Sea and surrounding areas has been and is experiencing a decline that impacts on the decrease of production every year with a large percentage and this condition also indicates the occurrence of potentially overfishing. The value of MSY utilization of capture fishery resources in the Sulawesi Sea based on Tumumpa Fishery Harbor data were 16,305.45 tons / year for HMSY and 1,664,59 trips / year for EMSY, with TAC of 13,044.36 tons / year.Keywords :  Capture fishery, MSY, Pelagic, Surplus Production Model, Tumumpa ABSTRAK Kegiatan penelitian ini berlangsung di Kota Manado, Provinsi Sulawesi Utara dengan kegiatan berpusat di Pelabuhan Perikanan Pantai (PPP) Tumumpa Manado. Aktivitas perikanan tangkap yang ditelaah berlangsung di kawasan perairan Laut Sulawesi dan sekitarnya berdasarkan data PPP Tumumpa Manado. Tujuan dari penelitian ini adalah untuk menganalisis nilai stok dan Maximum Sustainable Yield (MSY) ikan pelagis di Laut Sulawesi berdasarkan pendekatan model produksi surplus (Model Schaefer). Penelitan ini diharapkan dapat digunakan sebagai bahan pertimbangan dalam pengelolaan stok ikan pelagis di Laut Sulawesi dan sekitarnya, serta dapat digunakan sebagai dasar untuk penelitian selanjutnya. Penelitian ini menggunakan metode pengumpulan data sekunder berbentuk dokumen. Data yang diambil adalah data tangkapan ikan dan upaya penangkapan ikan atau effort (trip), dari tahun 2012 sampai dengan 2016 (5 Tahun). Hasil penelitian menunjukkan nilai produksi berbanding terbalik dengan nilai effort, di mana nilai produksi dari tahun 2012 sampai 2016 mengalami penurunan setiap tahunnya, sedangkan nilai effort dari tahun 2012 sampai tahun 2016 mengalami peningkatan. Kondisi yang terjadi ini mengindikasikan bahwa keberadaan stok ikan pelagis di Laut Sulawesi dan sekitarnya telah dan sedang mengalami penurunan yang berdampak pada penurunan produksi setiap tahun dengan persentase yang cukup besar di mana kondisi ini mengindikasikan terjadinya overfishing. Nilai MSY pemanfaatan sumber daya perikanan tangkap di Laut Sulawesi berdasarkan data PPP Tumumpa Manado sebesar 16.305,45 ton/tahun untuk HMSY, dan 1.664,59 trip/tahun untuk EMSY, dengan TAC sebesar 13.044,36 ton/tahun.Kata Kunci: Perikanan Tangkap, MSY, Pelagis, Model Produksi Surplus, Tumumpa


2020 ◽  
Vol 9 (1) ◽  
pp. 15-17
Author(s):  
Ernesto A Chávez

A brief review of the concept of Maximum Sustainable Yield (MSY) used in fisheries management is discussed. The convenience of assessing the exploited stocks with the aid of simulation is advised, because implies the possibility to analyze the age structure of the fishery in more detail, as compared to the traditional methods of fish stock assessment. Emphasis is given to the use of the MSY as limit reference point because as long as the Fishing Mortality or fishing effort required for that point is kept at lower values, the fishery will have a good chance to be sustainable. A mention of the Maximum Economic Yield is made, proposing its use a target for the management, because it is reached in general with lower F values then that for the MSY, and this way keeping the fishery in a healthy condition.


2006 ◽  
Vol 66 (1b) ◽  
pp. 263-277 ◽  
Author(s):  
N. O. Leite Jr. ◽  
M. Petrere Jr.

Quantitative analyses of the pink shrimp (Farfantepenaeus brasiliensis and Farfantepenaeus paulensis) fisheries were carried out using data collected from July 1999 to July 2001 from the trawling operations of the fishing fleet based in Santos/Guarujá, SP. According to classical models, the fishery is at its maximum sustainable yield. Therefore, reduction of the fishing effort and adequate season and area closures seem to be the best management actions for the pink shrimp fishery.


2021 ◽  
Vol 48 (2) ◽  
pp. 301-312
Author(s):  
Muhammad Abdur Rouf ◽  
Sheik Istiak Md Shahriar ◽  
Md Hafizur Rahman ◽  
Md Mehedi Hasan ◽  
Al Hasan Antu ◽  
...  

Maximum sustainable yield (MSY), fishing effort (fmsy) and total allowable catch (TAC) of major fishery in the Passur River, Bangladesh were estimated using surplus production model (Schaefer and Fox model) with observation-error estimator based on four years (2011-2014) catch and effort data. Fox model was especially highlighted in this study; the estimated value of MSY was 4.61 kg with corresponding fmsy of 13.51 units (200m2SBN/day). Moreover, the mean value of MSY and TAC with 95% confidence interval in stochastic method was 4.53 kg and 4.08 kg respectively with the 13.22 units of fishing effort (fmsy). The overall results provide clear evidence that the fishery of the Passur River is being overexploited in the months from December to March. Sustainable exploitation of this stock can be assured through reducing present fishing effort. In addition, TAC might be incorporated along with several existing fisheries management measures to ensure the compensation of this stock towards long term sustainability. Bangladesh J. Zool. 48(2): 301-312, 2020


1994 ◽  
Vol 51 (8) ◽  
pp. 1823-1831 ◽  
Author(s):  
John M. Hoenig ◽  
William G. Warren ◽  
Max Stocker

The Schaefer surplus production model relates equilibrium yield to fishing effort and can be fitted using just information on catch and fishing effort. Sometimes, the fitted model predicts a maximum sustainable yield (height of the parabola) that is clearly unrealistic. In this case, one may wish to use prior information on maximum sustainable yield either to constrain the height of the parabola or to provide a prior distribution for Bayesian estimation. To construct a Bayes estimator, one would generally specify a noninformative prior on the residual error variance and, possibly, on the width of the parabola; the prior distribution for height could be obtained by examining fisheries for similar stocks or species on a per unit area basis. Another possibility is to use an empirical Bayes estimator when data from several fisheries (e.g., individual lakes) are available for several years. The methodology is illustrated on catch and effort data for big-eye tuna (Thunnus obesus) and Dungeness crab (Cancer magister). The approach can be extended to other fishery models, including nonequilibrium production models. The prior distribution parameters can be allowed to depend on covariates.


Sign in / Sign up

Export Citation Format

Share Document