Pub Date : 2020-04-11DOI: 10.15578/ifrj.26.1.2020.11-17
R. K. Sulistyaningsih, I. Jatmiko, Maya Agustina
Frigate tuna (Auxis thazard) is one of the major commercial tuna species, both in industrial and small scale fisheries, particularly in the waters off Western Sumatera. In Indonesia, A. thazard is a group of locally called “tongkol” together with A. rochei, Thunnus tonggol, and Euthynnus affinis. This study describes a preliminary examination of frigate tuna catch from purse seine off the coast of western Sumatera (FMA 572). The data were collected daily by an enumerator on the fish landing site from 2013 to 2017, including fishing gear, number of days at sea, catch, length, and weight of frigate tuna. The fishing ground coordinate data provided by the observer on board the vessel. General Linear Model (GLM) with gamma was applied in this study to standardize the CPUE by year, quarter, season, and GT as fixed variables. The results showed that the variation of CPUE was mostly influenced by year and quarter, while season and fleet size (GT) showed less impact on the catch. In general, even though the catch trend declines during the observation years, the population of frigate tuna off the coast of western Sumatera (FMA 572) were considered sustainable.
{"title":"CPUE STANDARDIZATION OF FRIGATE TUNA (Auxis thazard) CAUGHT BY PURSE SEINE OFF THE COAST OF WESTERN SUMATERA (FMA 572)","authors":"R. K. Sulistyaningsih, I. Jatmiko, Maya Agustina","doi":"10.15578/ifrj.26.1.2020.11-17","DOIUrl":"https://doi.org/10.15578/ifrj.26.1.2020.11-17","url":null,"abstract":"Frigate tuna (Auxis thazard) is one of the major commercial tuna species, both in industrial and small scale fisheries, particularly in the waters off Western Sumatera. In Indonesia, A. thazard is a group of locally called “tongkol” together with A. rochei, Thunnus tonggol, and Euthynnus affinis. This study describes a preliminary examination of frigate tuna catch from purse seine off the coast of western Sumatera (FMA 572). The data were collected daily by an enumerator on the fish landing site from 2013 to 2017, including fishing gear, number of days at sea, catch, length, and weight of frigate tuna. The fishing ground coordinate data provided by the observer on board the vessel. General Linear Model (GLM) with gamma was applied in this study to standardize the CPUE by year, quarter, season, and GT as fixed variables. The results showed that the variation of CPUE was mostly influenced by year and quarter, while season and fleet size (GT) showed less impact on the catch. In general, even though the catch trend declines during the observation years, the population of frigate tuna off the coast of western Sumatera (FMA 572) were considered sustainable.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":"26 1","pages":"11-17"},"PeriodicalIF":0.0,"publicationDate":"2020-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45396029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-03DOI: 10.15578/ifrj.26.1.2020.1-10
U. Chodrijah, T. Hidayat, K. Wagiyo
Skipjack tuna ( Katsuwonus pelamis ) was one of the export commodities, where the demand and exploitation tend to increase, so sustainable fisheries management is needed based on biological data. The objective of the research was to study the several aspects of biology including of length of weight relationship, sex ratio maturity stage, gonada somatic index (GSI), length at first capture, and length at first maturity. The research was conducted in February - December 2015 in Toli-toli, Central Sulawesi. The results showed that the skipjack tuna growth pattern was allometrically positive (b= 3,318 for male and b = 3.3049 for female), where growth weight was faster than the increased length. The length of the first time capture skipjack tuna of pole and line (43.49 cmFL) was bigger than length at first maturity (41,007 cmFL). It means the mostly skipjack tuna caught have already spawned. The spawning season occurred throughout the year with spawning peaks are in April and September, with fecundity ranging from 450,570 to 1,707,390 eggs.
{"title":"SOME BIOLOGICAL ASPECTS OF SKIPJACK TUNA (Katsuwonus pelamis LINNAEUS, 1758) DI PERAIRAN TOLI-TOLI WATERS, CENTRAL SULAWESI","authors":"U. Chodrijah, T. Hidayat, K. Wagiyo","doi":"10.15578/ifrj.26.1.2020.1-10","DOIUrl":"https://doi.org/10.15578/ifrj.26.1.2020.1-10","url":null,"abstract":"Skipjack tuna ( Katsuwonus pelamis ) was one of the export commodities, where the demand and exploitation tend to increase, so sustainable fisheries management is needed based on biological data. The objective of the research was to study the several aspects of biology including of length of weight relationship, sex ratio maturity stage, gonada somatic index (GSI), length at first capture, and length at first maturity. The research was conducted in February - December 2015 in Toli-toli, Central Sulawesi. The results showed that the skipjack tuna growth pattern was allometrically positive (b= 3,318 for male and b = 3.3049 for female), where growth weight was faster than the increased length. The length of the first time capture skipjack tuna of pole and line (43.49 cmFL) was bigger than length at first maturity (41,007 cmFL). It means the mostly skipjack tuna caught have already spawned. The spawning season occurred throughout the year with spawning peaks are in April and September, with fecundity ranging from 450,570 to 1,707,390 eggs.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":"26 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2020-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44895763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-31DOI: 10.15578/ifrj.25.2.2019.91-101
T. Ernawati, A. Priatna, F. Satria
A biological reference point is a term used to explain of stock status using a biological approach as a basic of fisheries management. Biological reference points of painted spiny lobster Panulirus versicolor are limited in Karimunjawa waters. This study aims to investigate the stock status of P. versicolor and management options to ensure the sustainability of the resources. The research was conducted in Karimunjawa islands of the Java Sea by collecting lobster from local fishers from March to November 2016. A total of 495 lobster were measured, weighed, and their maturity status assessed to allow the size at maturity and selectivity of the fishery to be estimated. The size at maturity L50 (62.2 mm CL) and L95 (82.0 mm CL) were larger than SL50 (48.2 mm CL) and SL95 (75.0 mm CL), respectively. Natural mortality (M) which was 0.579 year-1 is lower than fishing mortality (F). The current spawning potential ratio (SPR) of P. versicolor is 19% at the current F of 0.82, which is below SPR limit of 20% and target reference point of 40%. Hence, to increase SPR level to 40%, the fishing mortality should be reduced by about 40% to 60%. Closed season, legal size, and defining no take zone are options to consider by fishery manager with appropriate surveillance control. Single or combining those measures can reduce its fishing mortality and take back the stocks to the level of target reference point.
{"title":"BIOLOGICAL REFERENCE POINTS OF PAINTED SPINY LOBSTER Panulirus versicolor (Latreille, 1804) IN KARIMUNJAWA WATERS, INDONESIA","authors":"T. Ernawati, A. Priatna, F. Satria","doi":"10.15578/ifrj.25.2.2019.91-101","DOIUrl":"https://doi.org/10.15578/ifrj.25.2.2019.91-101","url":null,"abstract":"A biological reference point is a term used to explain of stock status using a biological approach as a basic of fisheries management. Biological reference points of painted spiny lobster Panulirus versicolor are limited in Karimunjawa waters. This study aims to investigate the stock status of P. versicolor and management options to ensure the sustainability of the resources. The research was conducted in Karimunjawa islands of the Java Sea by collecting lobster from local fishers from March to November 2016. A total of 495 lobster were measured, weighed, and their maturity status assessed to allow the size at maturity and selectivity of the fishery to be estimated. The size at maturity L50 (62.2 mm CL) and L95 (82.0 mm CL) were larger than SL50 (48.2 mm CL) and SL95 (75.0 mm CL), respectively. Natural mortality (M) which was 0.579 year-1 is lower than fishing mortality (F). The current spawning potential ratio (SPR) of P. versicolor is 19% at the current F of 0.82, which is below SPR limit of 20% and target reference point of 40%. Hence, to increase SPR level to 40%, the fishing mortality should be reduced by about 40% to 60%. Closed season, legal size, and defining no take zone are options to consider by fishery manager with appropriate surveillance control. Single or combining those measures can reduce its fishing mortality and take back the stocks to the level of target reference point.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":"25 1","pages":"91-101"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43519930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-31DOI: 10.15578/ifrj.25.2.2019.75-90
F. Rochman, Watiniasih Ni Luh, Yuni Luh Putu Eswaryanti Kusuma
Southern Bluefin Tuna in spawning area of the Eastern Indian Ocean where the Indonesian’s longliners operated has a specific character in term of size, age, sex-specific growth rate and the population. The aims of this study are to determined changes in size/age, sex-specific growth rate and virtual population analysis of Southern Bluefin Tuna (SBT) in the spawning area. This study is important to find out the successful management of SBT in spawning area by looking at the catch at age/size movement, sex-specific growth analysis and the estimation of the population by virtual population analysis. In this study, we were used 452 pairs of otolith with fish sized from 134-196 cmFL and fish aged from 8-20 years. The growth equation was Lt = 191 (1-e-0,167(t+1,081)). Catch at age structure was distributed from 5-22 years with mean and mode of age were 9.63 and 9 years. The distribution of mode changed from year to year shifting to a younger fish. In 2012, the mode was 10 years but entering 2013-2014 the mode was shifted to 6 years. In 2015-2017, the mode was increased from 7 years (2015) to 8 years (2016) and 9 years (2017). The fishing pressure happened in the age group under 20 years. In 2012 to 2014, the highest fishing pressure respectively obtained in the age group of 13 to 11 years with an average length of 167 to 174 cmFL. Entering 2015 and 2016, the highest fishing pressure obtained in the age group of 6 years with an average length of 138 cmFL. The exploitation rate ranged from 0.14/year to 0.25/year meaning that the exploitation was in optimal condition.
{"title":"SOUTHERN BLUEFIN TUNA (Thunnus maccoyii) CAUGHT BY INDONESIA’S TUNA LONGLINERS IN THE SPAWNING AREA","authors":"F. Rochman, Watiniasih Ni Luh, Yuni Luh Putu Eswaryanti Kusuma","doi":"10.15578/ifrj.25.2.2019.75-90","DOIUrl":"https://doi.org/10.15578/ifrj.25.2.2019.75-90","url":null,"abstract":"Southern Bluefin Tuna in spawning area of the Eastern Indian Ocean where the Indonesian’s longliners operated has a specific character in term of size, age, sex-specific growth rate and the population. The aims of this study are to determined changes in size/age, sex-specific growth rate and virtual population analysis of Southern Bluefin Tuna (SBT) in the spawning area. This study is important to find out the successful management of SBT in spawning area by looking at the catch at age/size movement, sex-specific growth analysis and the estimation of the population by virtual population analysis. In this study, we were used 452 pairs of otolith with fish sized from 134-196 cmFL and fish aged from 8-20 years. The growth equation was Lt = 191 (1-e-0,167(t+1,081)). Catch at age structure was distributed from 5-22 years with mean and mode of age were 9.63 and 9 years. The distribution of mode changed from year to year shifting to a younger fish. In 2012, the mode was 10 years but entering 2013-2014 the mode was shifted to 6 years. In 2015-2017, the mode was increased from 7 years (2015) to 8 years (2016) and 9 years (2017). The fishing pressure happened in the age group under 20 years. In 2012 to 2014, the highest fishing pressure respectively obtained in the age group of 13 to 11 years with an average length of 167 to 174 cmFL. Entering 2015 and 2016, the highest fishing pressure obtained in the age group of 6 years with an average length of 138 cmFL. The exploitation rate ranged from 0.14/year to 0.25/year meaning that the exploitation was in optimal condition.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":"25 1","pages":"75-90"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42727313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-31DOI: 10.15578/ifrj.25.2.2019.64-74
U. J. Wisha, K. Ondara, W. A. Gemilang, G. A. Rahmawan, R. Dhiauddin, I. Ilham
Bordered with the Indian Ocean, Simeulue Islands is one of the outermost islands in Indonesia located in the west part of Aceh Province. Simeulue waters are productive areas due to the unpolluted condition yet and great of biomass. Three regions were particularly observed, those are Simeuluecut, Ganting, and Labuhan Bajau. In those areas, the existing marine tourism activities might influence the coral reef ecosystem studied. This study aimed to evaluate the condition of coral and coral reef fish in those three particular regions before mass bleaching event in 2016 triggered by ENSO. Point Intercept Transect (PIT) method was employed to record the percentage cover of coral, species diversity, and coral reef fish. Ganting waters was a moderate ecosystem area whith the percentage coverage was up to 45.62%. However, in Simeuluecut and Labuhan Bajau waters, the coral reef communities were excellent with coral percentage coverage reached 83.12% and 81.25 %, respectively. The highest abundance genera of coral reef fish was observed in Simueluecut waters. This condition was changed oppositely in 2016 when mass bleaching threatened Simeulue waters due to temperature anomaly triggered by ENSO phenomenon. The temperature increases almost 3oC for 6 months that undoubtedly induced bleaching that about 50% of coral colonies were dramatically declined in coral coverage and coral recruitment.
{"title":"CORAL REEF CONDITION IN RELATION TO CORAL REEF FISH ABUNDANCES BEFORE MASS BLEACHING EVENT IN SIMEULUE ISLANDS, ACEH","authors":"U. J. Wisha, K. Ondara, W. A. Gemilang, G. A. Rahmawan, R. Dhiauddin, I. Ilham","doi":"10.15578/ifrj.25.2.2019.64-74","DOIUrl":"https://doi.org/10.15578/ifrj.25.2.2019.64-74","url":null,"abstract":"Bordered with the Indian Ocean, Simeulue Islands is one of the outermost islands in Indonesia located in the west part of Aceh Province. Simeulue waters are productive areas due to the unpolluted condition yet and great of biomass. Three regions were particularly observed, those are Simeuluecut, Ganting, and Labuhan Bajau. In those areas, the existing marine tourism activities might influence the coral reef ecosystem studied. This study aimed to evaluate the condition of coral and coral reef fish in those three particular regions before mass bleaching event in 2016 triggered by ENSO. Point Intercept Transect (PIT) method was employed to record the percentage cover of coral, species diversity, and coral reef fish. Ganting waters was a moderate ecosystem area whith the percentage coverage was up to 45.62%. However, in Simeuluecut and Labuhan Bajau waters, the coral reef communities were excellent with coral percentage coverage reached 83.12% and 81.25 %, respectively. The highest abundance genera of coral reef fish was observed in Simueluecut waters. This condition was changed oppositely in 2016 when mass bleaching threatened Simeulue waters due to temperature anomaly triggered by ENSO phenomenon. The temperature increases almost 3oC for 6 months that undoubtedly induced bleaching that about 50% of coral colonies were dramatically declined in coral coverage and coral recruitment.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":"25 1","pages":"64-74"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42116332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-12DOI: 10.15578/ifrj.25.2.2019.123-131
R. Gustiano, Muhammad Hunaina Fariduddin Ath-thar, V. A. Prakoso, D. Radona, I. I. Kusmini
Pangasiid catfishes is an economic important catfish family for fishery. Nowadays, three species, Pangasius hypophtahlmus, P. boucorti, and P. djambal, are used in aquaculture. Among the genera in Pangasiidae, Helicophagus was less studied. Although this genus was less preferred than other popular species in Pangasiidae, it still has high commercial price. The present study was conducted to clarify the differences of the exist species in the genus Helicophagus based on biometric analyses. Twenty six specimens, collected from represent rivers in Southeast Asia, used for the material examined. Several type specimens deposited in museums were also added in the analyses. Thirty five characters were designed for measurement on the unique body conformation. Principal component analysis (PCA) was applied to distinguish different species and found strong characters for key identification and description. The results presented the data and information on the diagnosis, description, distribution, and ecology of each species. Key identification of each species are given. The three species (Helicophagus typus, H. waandersii, and H. leptorhynchus) enabled to show their differences based on eye diameter and vomerine toothplate length.
{"title":"DIAGNOSTIC AND DESCRIPTION OF ASIAN PANGASIID CATFISH GENUS Helicophagus FROM SOUTHEAST ASIA","authors":"R. Gustiano, Muhammad Hunaina Fariduddin Ath-thar, V. A. Prakoso, D. Radona, I. I. Kusmini","doi":"10.15578/ifrj.25.2.2019.123-131","DOIUrl":"https://doi.org/10.15578/ifrj.25.2.2019.123-131","url":null,"abstract":"Pangasiid catfishes is an economic important catfish family for fishery. Nowadays, three species, Pangasius hypophtahlmus, P. boucorti, and P. djambal, are used in aquaculture. Among the genera in Pangasiidae, Helicophagus was less studied. Although this genus was less preferred than other popular species in Pangasiidae, it still has high commercial price. The present study was conducted to clarify the differences of the exist species in the genus Helicophagus based on biometric analyses. Twenty six specimens, collected from represent rivers in Southeast Asia, used for the material examined. Several type specimens deposited in museums were also added in the analyses. Thirty five characters were designed for measurement on the unique body conformation. Principal component analysis (PCA) was applied to distinguish different species and found strong characters for key identification and description. The results presented the data and information on the diagnosis, description, distribution, and ecology of each species. Key identification of each species are given. The three species (Helicophagus typus, H. waandersii, and H. leptorhynchus) enabled to show their differences based on eye diameter and vomerine toothplate length.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46409693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-11DOI: 10.15578/ifrj.25.2.2019.103-112
K. Amri, Afrisa Novalina, B. Setyadji
Bullet tuna is considered as one of the important species for tuna purse seine fisheries in Indonesia, especially in archipelagic waters. However, little is known about its biological characteristics which proven to be pivotal in stock assessment. The purpose of this research was to determine some of the biological stock indicators for bullet tuna (Auxis rochei) from Banda Sea and its adjacent waters. The study was conducted from February to November 2016. The length of the bullet tuna caught were in between 18.5-32.7 cmFL (mode=24 cmFL). Growth pattern was isometric with b=3.01 and R2=0.84 Sex ratio was balanced between male and female (1:1). The spawning season allegedly from June to November. The length at 50% mature (L50) was 23.6 cmFL. A good indicator for the fisheries, where at least 75% of the mature fish caught were already spawned. The asymptotic length (L) was 33.63 cmFL, with coefficient of growth (K) around 0.73/year. Natural mortality (M) estimated at 1.87/year, fishing mortality (F) estimated at 2.20/year and total mortality (Z) was 4.07/year. The exploitation level (E) was estimated to be at maximum level (E=0.54/year), for precautionary purpose, the number of efforts should be reduced down to 8% from current effort.
{"title":"SOME BIOLOGICAL STOCK INDICATORS OF BULLET TUNA (Auxis rochei, Risso 1810) FROM BANDA SEA AND ITS ADJACENT WATERS","authors":"K. Amri, Afrisa Novalina, B. Setyadji","doi":"10.15578/ifrj.25.2.2019.103-112","DOIUrl":"https://doi.org/10.15578/ifrj.25.2.2019.103-112","url":null,"abstract":"Bullet tuna is considered as one of the important species for tuna purse seine fisheries in Indonesia, especially in archipelagic waters. However, little is known about its biological characteristics which proven to be pivotal in stock assessment. The purpose of this research was to determine some of the biological stock indicators for bullet tuna (Auxis rochei) from Banda Sea and its adjacent waters. The study was conducted from February to November 2016. The length of the bullet tuna caught were in between 18.5-32.7 cmFL (mode=24 cmFL). Growth pattern was isometric with b=3.01 and R2=0.84 Sex ratio was balanced between male and female (1:1). The spawning season allegedly from June to November. The length at 50% mature (L50) was 23.6 cmFL. A good indicator for the fisheries, where at least 75% of the mature fish caught were already spawned. The asymptotic length (L) was 33.63 cmFL, with coefficient of growth (K) around 0.73/year. Natural mortality (M) estimated at 1.87/year, fishing mortality (F) estimated at 2.20/year and total mortality (Z) was 4.07/year. The exploitation level (E) was estimated to be at maximum level (E=0.54/year), for precautionary purpose, the number of efforts should be reduced down to 8% from current effort. ","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42958919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-22DOI: 10.15578/IFRJ.25.1.2019.1-10
A. Zamroni, T. Ernawati
Short mackerel fish (Rastrelliger brachysoma) is one of small pelagic fish mostly exploited by mini purse seine fishing gear. Exploitation of short mackerel by mini purse seine has an increasing trend every year and suspected to have negative impacts. One of the negative impact is the decrease of fish abundance, so it is necessary to carry out population dynamics and Spawning Potential Ratio (SPR) studies through length-based approach to provide exploitation indicator as biology reference point. The result of length-weight relationship analysis shows that the growth pattern (b = 2.3483) is negative allometry. The estimated length at first capture and its first sexual maturity analysis shows that the value of length at first capture (Lc = 15.4 cm FL) is greater than the length at first sexual maturity (Lm = 15.21 cm FL). The estimated maximum length (L∞) is 21.05 cm FL with growth rates (K) is 1.01 year-1 and t0 at -0.177 years. The estimated total mortality (Z) was 5.48 year-1, natural mortality (M) was 2.02 year-1 and fishing mortality (F) was 3.46 year-1. The predicted exploitation rate (E) is 0.63 which higher than the optimum value (E = 0.5). The estimated length-based SPR (LB-SPR) of 30% (SPR > 20% or above limit) means that short mackerel fishing activity has full exploitation.
短吻鲭鱼（Rastrelliger brachysoma）是一种主要由小型围网渔具开发的小型中上层鱼类。小型围网每年都有增加的趋势，并被怀疑会产生负面影响。其中一个负面影响是鱼类丰度的下降，因此有必要通过基于长度的方法进行种群动态和产卵潜力比（SPR）研究，以提供开发指标作为生物学参考点。长重关系分析结果表明，生长模式（b=2.3483）为负异速生长。首次捕获时的估计长度及其首次性成熟度分析表明，首次捕获时长度的值（Lc=15.4 cm FL）大于首次性成熟时的长度（Lm=15.21 cm FL）。估计的最大长度（L∞）为21.05 cm FL，生长率（K）为1.01年-1，t0为-0.177年。估计总死亡率（Z）为5.48年-1，自然死亡率（M）为2.02年-1，渔业死亡率（F）为3.46年-1。预测的开发率（E）为0.63，高于最佳值（E=0.5）。基于长度的SPR（LB-SPR）估计值为30%（SPR>20%或高于极限），意味着短鱼捕捞活动具有充分的开发性。
{"title":"POPULATION DYNAMIC AND SPAWNING POTENTIAL RATIO OF SHORT MACKEREL (Rastrelliger brachysoma Bleeker, 1851) IN THE NORTHERN COAST OF JAVA","authors":"A. Zamroni, T. Ernawati","doi":"10.15578/IFRJ.25.1.2019.1-10","DOIUrl":"https://doi.org/10.15578/IFRJ.25.1.2019.1-10","url":null,"abstract":"Short mackerel fish (Rastrelliger brachysoma) is one of small pelagic fish mostly exploited by mini purse seine fishing gear. Exploitation of short mackerel by mini purse seine has an increasing trend every year and suspected to have negative impacts. One of the negative impact is the decrease of fish abundance, so it is necessary to carry out population dynamics and Spawning Potential Ratio (SPR) studies through length-based approach to provide exploitation indicator as biology reference point. The result of length-weight relationship analysis shows that the growth pattern (b = 2.3483) is negative allometry. The estimated length at first capture and its first sexual maturity analysis shows that the value of length at first capture (Lc = 15.4 cm FL) is greater than the length at first sexual maturity (Lm = 15.21 cm FL). The estimated maximum length (L∞) is 21.05 cm FL with growth rates (K) is 1.01 year-1 and t0 at -0.177 years. The estimated total mortality (Z) was 5.48 year-1, natural mortality (M) was 2.02 year-1 and fishing mortality (F) was 3.46 year-1. The predicted exploitation rate (E) is 0.63 which higher than the optimum value (E = 0.5). The estimated length-based SPR (LB-SPR) of 30% (SPR > 20% or above limit) means that short mackerel fishing activity has full exploitation.","PeriodicalId":31292,"journal":{"name":"Indonesian Fisheries Research Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43102787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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