Determining the stock status of snapper (Lutjanus sp.) using surplus production model: a case study in Banyuasin coastal waters, South Sumatra, Indonesia

Tujuan utama makalah ini adalah mengevaluasi kondisi stok ikan pelagis kecil (dengan ikan layang Decapterus spp. sebagai acuan) sebagai pembangkit ekonomi di pantai Utara Jawa perairan laut Jawa WPPNRI 712. Analisis dilakukan sejalan dengan tren penurunan aktivitas penangkapan kapal pukat cincin yang berpangkalan di Pekalongan Jawa Tengah yang telah berlangsung selama hampir dua dekade. Teori klasik tentang penangkapan ikan mengisyaratkan bahwa pemulihan populasi ikan dapat berlangsung cepat jika penangkapan ikan dihentikan pada rentang waktu tertentu. Analisis menggunakan pendekatan surplus produksi non-ekuilibrium dengan bantuan perangkat aplikasi ASPIC 7 dan Kobe plot digunakan untuk memetakan perubahan arah status stok ikan pelagis kecil yang berkaitan langsung dengan perilaku perkembangan perikanan pukat cincin di laut Jawa pada kurun waktu 1976 - 2014. Hasil penelitian menunjukkan bahwa penurunan drastis baik jumlah armada pukat cincin maupun aktivitas penangkapannya akibat rendahnya peluang keberhasilan dan tingginya investasi operasional hampir dua dekade telah telah memberikan peluang terhadap pemulihan stok secara alamiah menuju tingkat biomassa optimal. Pergerakan status biomasa dan mortalitas penangkapan ikan pelagis kecil secara tahunan yang ditampilkan melalui penggunaan Kobe plot memberikan indikasi bahwa kondisi stok ikan setelah tahun 2015 mengarah pada status yang cenderung baik. The main objective of this paper is to evaluate the status and trend of small pelagic fish stocks (Decapterus spp.) as a major driver of economics in north coast of Java correspond to a direct reduction of purse seine fishing activities at around two decades. Classical theory of fishing suggests that rapid population recovery occurs when fishing pressures is reduced. These phenomenons were analyzed by applying non-equilibrium surplus production model incorporate covariance of the programs package of Aspic 7. Simple Kobe plots were also applied to track the annual trend of stock status directly which presumably related to the course of fisheries development. The results showed that drastic decline of fishing pressures of both number of purse seine fleet and their activity within the last decade provided an opportunity of stock recovery at optimum biomass levels. Applying simple Kobe plots indicates the stock status and trend in 2015 relatively in rebuilding condition

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STATUS STOK GENUS Rastrelliger spp. SEBAGAI DASAR PENGELOLAAN PERIKANAN (STUDI KASUS PERAIRAN SELAT SUNDA)

Jurnal Perikanan Universitas Gadjah Mada ◽

10.22146/jfs.12424 ◽

2016 ◽

Vol 18 (2) ◽

pp. 73

Author(s):

Wulandari Sarasati ◽

Mennofatria Boer ◽

Sulistiono Sulistiono

Keyword(s):

Maximum Sustainable Yield ◽

Production Model ◽

Sustainable Yield ◽

Growth Coefficient ◽

Surplus Production ◽

Stock Status ◽

Surplus Production Model ◽

Exploitation Rate ◽

Two Peaks ◽

Recruitment Period

The Rastrelliger spp. is one of the important commodities of the Sunda Strait. This research aimsto analyze the stock status of Rastrelliger spp. Including R. faughni, R. kanagurta and R. brachysoma in Sunda Strait that landed at the Fishery Harbor (PPP) Labuan, Banten. The sampling was conducted in April-August 2015. The data was collected using Random stratified sampling based on the fish size, small, medium and large. The length of the sample was measured and classified into male and female. The data were analyzed using FISAT II ELEFAN I software to present the stock with growth, recruitment, surplus production model, and mortality and rate of exploitation parameters. The results show that R. faughni has L∞ values for females and males respectively of 264.00 mm and 288.69 mm, 293.09 mm and 330.24 mm R. kanagurta and R. brachysoma 272.04 mm and 286.42. Growth Performs Index (GPI) on R. faughni of 4.2758, R. kanagurta of 4.1673, and on R. brachysoma of 4.2076. The growth coefficient of female and male R. faughni was 0.22 and 0.16, R. kanagurta of 0.24 and 0.10, and R. brachysoma 0.20 and 0.13. The level of recruitment of each varies but overall undergoes two peaks during the recruitment period. Maximum Sustainable Yield (MSY) for the Rastrelliger spp. 1,919.02 tons and FMSY (Effort MSY) for 16,766 trips. Furthermore, the mortality rate of arrest (F) R. faughni amounted to 14.53, R. kanagurta 9.43, and R. brachysoma 1.74. The estimation of stock status has never been detached from the exploitation rate. The rate of exploitation for R. faughni, and that is equal to 0.98, R. kanagurta of 0.98, and R. brachysoma 0.85. Judging from the rate of exploitation can be expected the three fish of the Rastrelliger spp. In the Sunda Strait has been over exploited because it has exceeded the limits of optimum exploitation rate.

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The status of Japanese fisheries relative to fisheries around the world

ICES Journal of Marine Science ◽

10.1093/icesjms/fsx002 ◽

2017 ◽

Vol 74 (5) ◽

pp. 1277-1287 ◽

Cited By ~ 22

Author(s):

Momoko Ichinokawa ◽

Hiroshi Okamura ◽

Hiroyuki Kurota

Keyword(s):

Maximum Sustainable Yield ◽

Production Model ◽

Structured Population Model ◽

Total Allowable Catch ◽

Quick Recovery ◽

Stock Status ◽

Surplus Production Model ◽

The Status ◽

Stock Recruitment ◽

Age Structured

We present the first quantitative review of the stock status relative to the stock biomass (B) and the exploitation rate (U) that achieved the maximum sustainable yield (MSY) (BMSY and UMSY, respectively) for 37 Japanese stocks contributing 61% of the total marine capture production in Japan. BMSY and UMSY were estimated by assuming three types of stock-recruitment (S-R) relationships and an age-structured population model or by applying a surplus production model. The estimated stock status shows that approximately half of the stocks were overfishing (U/UMSY > 1), and approximately half of the stocks were overfished (B/BMSY < 0.5) during 2011–2013. Over the past 15 years, U decreased and B slightly increased on average. The rate of decrease in the U of the stocks managed by the total allowable catch (TAC) was significantly greater than that of the other stocks, providing evidence of the effectiveness of TAC management in Japan. The above statuses and trends were insensitive to the assumption of the S-R relationship. The characteristics of Japanese stocks composed mainly of resources with relatively high natural mortality, i.e. productivity, suggest that Japanese fisheries have great potential of exhibiting a quick recovery and increasing their yield by adjusting the fishing intensity to an appropriate level.

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Fisheries Reference Point and Stock Status of Croaker Fishery (Sciaenidae) Exploited from the Bay of Bengal, Bangladesh

Journal of Marine Science and Engineering ◽

10.3390/jmse10010063 ◽

2022 ◽

Vol 10 (1) ◽

pp. 63

Author(s):

Partho Protim Barman ◽

Md. Mostafa Shamsuzzaman ◽

Petra Schneider ◽

Mohammad Mojibul Hoque Mozumder ◽

Qun Liu

Keyword(s):

Bay Of Bengal ◽

Maximum Sustainable Yield ◽

Reference Points ◽

Production Model ◽

Fishing Pressure ◽

Surplus Production ◽

Stock Status ◽

Management Measures ◽

Production Models ◽

The Monte Carlo Method

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > BMSY and F < FMSY indicated the safe biomass and fishing status. The calculated F/FMSY was 0.89, 0.87, and 0.81, and B/BMSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB.

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Population changes in rattail species on the Chatham Rise

10.26686/wgtn.17007577 ◽

2021 ◽

Author(s):

◽

Kathleen Large

Keyword(s):

Maximum Likelihood ◽

Stock Assessment ◽

Production Model ◽

Likelihood Method ◽

Model Parameters ◽

Important Species ◽

Surplus Production ◽

Surplus Production Model ◽

Abundance Indices ◽

The Impact

<p>The aim of this project was to conduct a stock assessment to determine the population dynamic characteristics of rattail species taken as bycatch in the hoki, hake and ling fishery on the Chatham Rise. No quantitative assessment of the current size of rattail populations , and how these may have changed over time, has been carried out before. There is interest in the need to quantify the impact of commercial fishing on the rattail populations, as rattails (Macrouridae family) are considered to be an ecologically important species complex in the deep ocean, and there may be the potential for the development of a commercial fishery based on their value as processed fishmeal. The minimum data required for a stock assessment are an abundance index and a catch history. Abundance indices are available for over 20 species of rattail produced from scientific surveys conducted annually on the Chatham Rise since 1992. Catch histories for individual rattail species in the same area are not available. A method was developed to reconstruct commercial catches of rattails from commercial effort data and survey catch and effort data. A surplus production model was fitted to the reconstructed catch data and survey abundance indices, using maximum likelihood and Bayesian methods to estimate model parameters and uncertainty. A surplus production model has two components: an observation model for abundance indices and a process model for population dynamics. Maximum likelihood estimation was applied to a model that specified errors for the observations only, and this produced estimates that had wide confidence intervals. A Bayesian approach was then taken to fit a statespace version of the model that incorporates errors associated with the observation and process models. While the Bayesian method produced more plausible parameter estimates (in comparison to the maximum likelihood method) and parameter uncertainty was reduced, our analysis indicated the posterior estimates were highly sensitive to the specification of different priors. There may be several reasons for these results, including: the small number of observations, lack of contrast in the data and mis-specification of the model. Meaningful estimates of the absolute size of rattail populations are not possible with these results, where estimates can vary by orders of magnitude depending on prior specification. This implies that more work needs to be done to develop more effective methods that can be used to help inform decisions regarding the management of these fish populations. Improving data collection, investigating informative priors and extending/respecifying the model are considered worthwhile avenues of future work to improve stock assessments of rattails.</p>

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DEPLESI SUMBER DAYA IKAN TUNA DAN CAKALANG DI INDONESIA

Jurnal Sosial Ekonomi Kelautan dan Perikanan ◽

10.15578/jsekp.v13i2.6906 ◽

2019 ◽

Vol 13 (2) ◽

pp. 167

Author(s):

Maulana Firdaus ◽

Akhmad Fauzi ◽

A Faroby Falatehan

Keyword(s):

Resource Depletion ◽

Production Model ◽

Economic Potential ◽

Average Volume ◽

Negative Numbers ◽

Average Value ◽

Surplus Production ◽

Fish Resources ◽

Surplus Production Model ◽

The World

ABSTRAKTuna dan cakalang memiliki potensi ekonomi yang besar di Indonesia. Beberapa penelitian menunjukkan bahwa kedua komoditas ini telah menunjukkan gejala over fishing di dunia, termasuk Indonesia. Penelitian ini bertujuan untuk mengestimasi seberapa besar deplesi ikan tuna dan cakalang di Indonesia. Deplesi sumber daya dihitung melalui perkiraan stok dan tingkat hasil lestari dengan menggunakan model produksi surplus dan estimasi parameter menggunakan metoda Clarke Yoshimoto Pooley (CYP). Nilai deplesi diperoleh dari perkalian volume deplesi dengan unit rent. Hasil penelitian menunjukkan bahwa volume rata-rata deplesi sumber daya ikan tuna dan cakalang pada periode 1992-2015 adalah (-) 2.828 ton per tahun. Rata-rata nilai deplesi sumber daya ikan tuna dan cakalang menunjukkan angka negatif, yaitu (-) Rp131,89 miliar per tahun. Nilai negatif ini menunjukkan bahwa selama periode 1992-2015, stok sumber daya ikan tuna dan cakalang mengalami penurunan sebesar 2.828 ton per tahun dengan nilai potensi kerugian atau kehilangan akibat penurunan stok yang mencapai Rp131,89 miliar per tahun.Title: Tuna And Skipjack Resources Depletion In IndonesiaABSTRACTTuna and Skipjack has a great economic potential in Indonesia. Several studies have shown that these commodities have symptomed of over-fishing in the world, including Indonesia. This study aims to estimate the extent of tuna and skipjack depletion in Indonesia. Resource depletion is calculated through stock estimates and sustainable yield levels using surplus production model and parameter estimation of Clark Yoshimoto Pooley (CYP) method. Depletion value is obtained from multiplication of depletion volume with unit rent. Results of the study showed that the average volume of depletion of tuna and skipjack resources in the period 1992-2015 was (-) 2,828 tons per year. The average value of tuna and skipjack resource depletion showed negative numbers, ie (-) IDR 131.89 billion per year. This negative value indicates that during the period 1992-2015, the stock of tuna and skipjack fish resources decreased by 2.828 tons per year with the potential value of loss or loss due to a decrease in stock which reached IDR131,89 billion per year.

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Penentuan Status Pemanfaatan dan Pengelolaan Ikan Tongkol (Auxis rochei) yang Tertangkap di Perairan Bolaang-Mongondow Selatan dan Bolaang-Mongondow Timur Sulawesi Utara

d'CARTESIAN ◽

10.35799/dc.9.1.2020.25726 ◽

2020 ◽

Vol 9 (1) ◽

pp. 1

Author(s):

Ladi Beatriex Deeng ◽

Hanny A H Komalig ◽

John S Kekenusa

Keyword(s):

Maximum Sustainable Yield ◽

Production Model ◽

Model Data ◽

Biological Resource ◽

Surplus Production ◽

North Sulawesi ◽

Surplus Production Model ◽

The Status ◽

Level Of Effort

LADI BEATRIEX DEENG. Determination of Utilization and Management Status of Bonito (Auxis Rochei) Caught in South Bolaang-Mongondow and East Bolaang-Mongondow Waters of North Sulawesi. Supervised by Mr. JOHN S. KEKENUSA as main supervisor, and Mr. HANNY A. H. KOMALIG as co-supervisor.Bonito (Auxis rochei), needs to be managed properly because even though it is a renewable biological resource, it can experience overfishing, depletion or extinction. One way to approach the management of fish resources is by modeling. The analysis was carried out aiming to determine the status of utilization and management of bonito and maximum sustainable yield (MSY) using the Surplus Production Model. Data on catching and efforts to catch bonito is collected from the Marine and Fisheries Service of South Bolaang-Mongondow Regency and East Bolaang-Mongondow of North Sulawesi. The surplus production model that can be used to determine the catch of bonito is the Schaefer model. The maximum sustainable catch of bonito is 869.556 tons per year, obtained at the level of catching effort of 933 trips. For 2017 the level of utilization is 64.95 % so that production can still be increased, with a level of effort of 73.74 % indicating the level of effort that is not optimal and can still be increased. Keywords : Bonito, Surplus Production Model, South Bolaang-Mongondow and East Bolaang-Mongondow Regency

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