scholarly journals Estimation of birthdates and catch-at-age using length frequency analysis (LFA), with application for skipjack tuna (Katsuwonus pelamis) caught in the Southwest Atlantic

2004 ◽  
Vol 61 (5) ◽  
pp. 798-811 ◽  
Author(s):  
Humber A. Andrade ◽  
Paul G. Kinas
Keyword(s):  
Frequency Analysis ◽  
Growth Parameters ◽  
Information Criterion ◽  
Skipjack Tuna ◽  
Length Frequency ◽  
Southwest Atlantic ◽  
Katsuwonus Pelamis ◽  
Length Data ◽  
Length Frequency Data ◽  
Length Frequency Analysis

Abstract Converting length frequencies into age frequencies is an important component of a fisheries assessment. In this paper we use a length frequency analysis (LFA) to estimate birthdates after converting length data into catch-at-age, and use simulation studies to compare model-selection criteria and to examine the reliability of the resulting estimates. Deviance and an adaptation of the Akaike Information Criterion performed best. LFA results in useful estimates of birthdates and of catch-at-age if reliable length frequency data and estimates of growth parameters are available. The analysis is applied to skipjack tuna (Katsuwonus pelamis) caught in the Southwest Atlantic Ocean. Although spawning is reported to be seasonal in subtropical waters, the birthdates of the fish caught there were spread uniformly across the year. Young skipjack become vulnerable to fishing mainly in the first quarter of each year. Recruitment of strong year classes did not affect fishery yields equally in the Southwest Atlantic and the Caribbean Sea, so the assumption of a unit western stock for management purposes and the stock structure of skipjack in the Atlantic need further evaluation.

scholarly journals A Bayesian hierarchical approach to estimate growth parameters from length data of narrow spread

2019 ◽  
Vol 77 (2) ◽  
pp. 613-623
Author(s):  
Shijie Zhou ◽  
Sarah Martin ◽  
Dan Fu ◽  
Rishi Sharma
Keyword(s):  
Growth Parameters ◽  
Fish Growth ◽  
Hierarchical Approach ◽  
Length Frequency ◽  
Age Classes ◽  
Bayesian Hierarchical ◽  
Gear Selectivity ◽  
Length Data ◽  
Longtail Tuna ◽  
Length Frequency Data

Abstract Estimating fish growth from length frequency data is challenging. There is often a lack of clearly separated modes and modal progression in the length samples due to a combination of factors, including gear selectivity, slowing growth with increasing age, and spatial segregation of different year classes. In this study, we present an innovative Bayesian hierarchical model (BHM) that enables growth to be estimated where there are few distinguishable length modes in the samples. We analyse and identify the modes in multiple length frequency strata using a multinormal mixture model and then integrate the modes and associated variances into the BHM to estimate von Bertalanffy growth parameters. The hierarchical approach allows the parameters to be estimated at regional levels, where they are assumed to represent subpopulations, as well as at species level for the whole stock. We carry out simulations to validate the method and then demonstrate its application to Indian Ocean longtail tuna (Thunnus tonggol). The results show that the estimates are generally consistent with the range of estimates reported in the literature, but with less uncertainty. The BHM can be useful for deriving growth parameters for other species even if the length data contain few age classes and do not exhibit modal progression.

Age and growth of the daggernose shark, Isogomphodon oxyrhynchus, from northern Brazil

2000 ◽  
Vol 51 (4) ◽  
pp. 339 ◽  
Author(s):  
Rosangela Lessa ◽  
Francisco M. Santana ◽  
Vandick Batista ◽  
Zafira Almeida
Keyword(s):  
Frequency Analysis ◽  
Growth Curve ◽  
Growth Parameters ◽  
Age And Growth ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Alizarin Red ◽  
Northern Brazil ◽  
Biological Differences ◽  
Length Frequency Analysis

Age and growth of the daggernose shark, Isogomphodon oxyrhynchus, from northern Brazil were determined from 105 vertebral sections stained with alizarin red-S representing 46 males, 52 females and 7 specimens of unknown sex (58.4 to 141 cm-TL) and verified with length–frequency analysis of 1135 specimens (632 females and 503 males, 58–160 cm ). Marginal increments did not show significant differences throughout the year, and it was assumed that one band is formed annually. Different tests provided varying results for growth curve comparisons between sexes; the curves were similar, despite biological differences. von Bertalanffy growth parameters estimated from back-calculated mean lengths, observed mean lengths-at-age and length–frequency analysis were of the same magnitude. Parameters generated from observed length-at-age were chosen for describing growth for the species: L• 171.4 cm, k 0.12 year –1 and t0 –2.612 years. The largest female aged from vertebrae was 12 years old, whereas the largest male was aged at 7 years. Neonates, ~42.3 cm, showed one band in the vertebrae, formed at birth, or soon thereafter. Males are mature at 103 cm or 5–6 years and females at 115 cm or 6–7 years. Resumo. A idade e o crescimento do cação quati, Isogomphodon oxyrhynchus, do norte do Brasil foi determinada usando 105 vértebras seccionadas e coradas com alizarina vermelha-S de 46 machos, 52 fêmeas e 7 exemplares de sexo indeterminado (58,4–141 cm-CT). Análise de distribuição de frequência de comprimentos de 1135 indivíduos (632 femeas e 503 machos, 58–160 cm) foi utilizada como método de verificação. Os incrementos marginais não mostraram diferenças significativas ao longo do ano, assumindo-se que uma banda é formada anualmente. Com diferentes testes, usados para comparar curvas de crescimento entre os sexos, obteve-se resultados conflitantes; o crescimento foi considerado idêntico entre os sexos, apesar das diferenças biológicas entre machos e fêmeas. Os parâmetros de von Bertalanffy estimados do retrocálculo, comprimentos médios observados e da análise de comprimentos foram semelhantes, tendo sido escolhidos para descrever o crescimento da espécie: L• 8171,4 cm; k 0,12 year –1 et 0 –2,612 years. Amaior fêmea cuja idade foi estimada pelas vértebras tinha 12 anos enquanto o maior macho tinha 7 anos. Recém-nascidos de 42,3 cm apresentavam uma banda nas vertebras, formada ao nascer, ou logo depois do nascimento. Machos estão maduros em 103 cm ou 5–6 anos e fêmeas em 115 cm ou 6–7 anos.

scholarly journals Temporal variation, growth and natural mortality of two species of mojarras (Perciformes: Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico

2013 ◽  
Vol 5 ◽  
pp. 57
Author(s):  
José Luis Bonilla-Gómez ◽  
Maribel Badillo-Alemán ◽  
Alfredo Gallardo-Torres ◽  
Xavier Chiappa-Carrara
Keyword(s):  
Seasonal Variation ◽  
Frequency Analysis ◽  
Coastal Lagoon ◽  
Growth Parameters ◽  
Model Parameters ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Tropical Coastal Lagoon ◽  
Length Frequency Analysis

This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of theYucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season)were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03Lt2.92 in E. argenteus and W = 7.314E-03 Lt2.92 in E. gula. Growth parameters of von Bertalanffy growthfunction (VBGF) by length frequency analysis were in E. argenteus: L∞ = 13.65 cm, k = 0.54 year-1 and t0= - 0.37 years; and in E. gula: L∞ = 12.60 cm, k = 0.68 year-1 and t0 = - 0.28 years. Additionally, estimatednatural mortality in E. gula was 1.50 year-1 and in E. argenteus was 1.9 year-1. This study presents the firstestimation for both species of model parameters, growth performance index and mortality for the Yucatan Peninsula, which is relevant for the proper implementation of conservation measures for E. gula and E. argenteus in an important coastal zone of the Yucatan Peninsula.Se reportan la variación temporal, los parámetros de crecimiento y la mortalidad natural para Eucinostomus gula y Eucinostomus argenteus que habitan en la laguna costera tropical La Carbonera, al noroeste de la península de Yucatán, México. Los especímenes fueron recolectados entre abril de 2009 a marzo de 2010. Un total de 2 700 organismos de E. gula (> 80% en la estación lluviosa) y 1 577 organismos de E. argenteus (> 50% en la estación seca) fueron recolectados durante el período de estudio. Se determinó la relación peso-longitud (RPL) como: P = 8.323E-03 Lt 2.92 en E. argenteus y P = 7.314E-03  Lt2.92 en E. gula.  Para E. argenteus, los parámetros de crecimiento de la ecuación de crecimiento de von Bertalanffy (ECVB) fueron: L∞ = 13.65 cm,  k = 0.54 año-1 y t0 = - 0.37 años; mientras que para E. gula fueron: L∞ = 12.60 cm, k = 0.68 año-1 y t0 = - 0.28 años. La mortalidad natural en E. gula fue 1.50 año-1 y en E. argenteus fue 1.9 año-1. Este estudio presenta la primera estimación para ambas especies de los modelos de crecimiento, el índice del desempeño de crecimiento y la mortalidad natural para la península de Yucatán, lo que es relevante para la adecuada implementación de medidas de conservación de E. gula y E. argenteus en una valiosa zona costera de la península de Yucatán.

scholarly journals PARAMETER POPULASI DAN POLA REKRUITMEN IKAN TONGKOL LISONG (Auxis rochei Risso, 1810) DI PERAIRAN BARAT SUMATERA

2015 ◽  
Vol 7 (3) ◽  
pp. 129
Author(s):  
Tegoeh Noegroho ◽  
Umi Chodrijah
Keyword(s):  
Mortality Rate ◽  
Frequency Analysis ◽  
Growth Parameters ◽  
Fork Length ◽  
Total Mortality ◽  
Von Bertalanffy ◽  
Population Parameters ◽  
Length Frequency ◽  
Exploitation Rate ◽  
Length Frequency Analysis

Perikanan neritik tuna di perairan Barat Sumatera berkembang pesat beberapa dekade terakhir ini. Sementara belum banyak diperoleh hasil penelitian tentang populasi ikan tongkol lisong (Auxis rochei). Penelitian tentang parameter populasi dan pola rekruitmen ikan tongkol lisong dilakukan pada bulan Februari-Desember 2013 di beberapa lokasi pendaratan ikan di Barat Sumatera. Tujuan penelitian ini adalah untuk memperoleh laju pertumbuhan, panjang asimptotik, laju kematian, laju eksploitasi, dan pola rekruitmen ikan tongkol lisong (Auxis rochei). Estimasi parameter populasi menggunakan model analitik berdasarkan program “Electronic Length Frequency Analysis (ELEFAN 1)”. Data frekuensi panjang dikumpulkan berkesinambungan di beberapa tempat pendaratan utama. Hasil penelitian menunjukkan panjang cagak ikan tongkol lisong yang tertangkap berada pada kisaran 11-42 cmFL. Parameter pertumbuhan Von Bertalanffy diperoleh nilai laju pertumbuhan (K) sebesar 0,54/tahun, panjang asimptotik (L ) sebesar 43,5 cm FL, dan umur ikan pada saat panjang ke-0 (-t0) sebesar -0,076/tahun. Laju mortalitas total (Z) sebesar 1,96/tahun. Laju kematian karena penangkapan (F) sebesar ,07/tahun, dan laju kematian alami (M) 0,89/tahun. Laju eksploitasi (E) tongkol lisong di Barat Sumatera adalah 0,49/tahun atau berada pada tingkat eksploitasi moderat. Pola rekrutmen tongkol lisong terjadi dua kali dalam setahunnya, yaitu mencapai puncak pada bulan Maret dan Juni.Neritic tuna fishery in theWest Sumatra waters was developed very intensively in the captured.Meanwhile, study population of bullet tuna (Auxis rochei) in those are still limited. Research in population parameters and recruitmen pattern of bullet tuna has been conducted in February-December 2013 based on several landing place inWest Sumatra. The aim of this study is to obtain asymptotic length, mortality rate, exploitation rate, and recruitment pattern of bullet tuna (Auxis rochei). Estimation of population parameters using an analytical model based on the program “Electronic Length Frequency Analysis (ELEFAN 1)”. Length frequency data collected continuously in themain landing places The results showed the fork length of bullet tuna was caught in the range 11-42 cm FL. Von Bertalanffy growth parameters obtained the growth rate value (K) of 0,54/year, asymptotic length (L ) of 43,5 cm FL, and fish age when the length to the-0 (-t0) of -0,076/year. Total mortality was 1,96/year. Fishing mortality rate (F) was 1,07/year and natural mortality rate (M) 0,89/year. The exploitation rate (E) of bullet tiuna in West Sumatra was 0,49 / year or are at a moderate level of exploitation. Recruitment patterns of bullet tuna happen twice in a year, which reached a peak in March and June.

scholarly journals Temporal variation, growth and natural mortality of two species of mojarras (Perciformes: Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico

2013 ◽  
Vol 5 ◽  
pp. 57
Author(s):  
José Luis Bonilla-Gómez ◽  
Maribel Badillo-Alemán ◽  
Alfredo Gallardo-Torres ◽  
Xavier Chiappa-Carrara
Keyword(s):  
Seasonal Variation ◽  
Frequency Analysis ◽  
Coastal Lagoon ◽  
Growth Parameters ◽  
Model Parameters ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Tropical Coastal Lagoon ◽  
Length Frequency Analysis

This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of theYucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season)were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03Lt2.92 in E. argenteus and W = 7.314E-03 Lt2.92 in E. gula. Growth parameters of von Bertalanffy growthfunction (VBGF) by length frequency analysis were in E. argenteus: L∞ = 13.65 cm, k = 0.54 year-1 and t0= - 0.37 years; and in E. gula: L∞ = 12.60 cm, k = 0.68 year-1 and t0 = - 0.28 years. Additionally, estimatednatural mortality in E. gula was 1.50 year-1 and in E. argenteus was 1.9 year-1. This study presents the firstestimation for both species of model parameters, growth performance index and mortality for the Yucatan Peninsula, which is relevant for the proper implementation of conservation measures for E. gula and E. argenteus in an important coastal zone of the Yucatan Peninsula.Se reportan la variación temporal, los parámetros de crecimiento y la mortalidad natural para Eucinostomus gula y Eucinostomus argenteus que habitan en la laguna costera tropical La Carbonera, al noroeste de la península de Yucatán, México. Los especímenes fueron recolectados entre abril de 2009 a marzo de 2010. Un total de 2 700 organismos de E. gula (> 80% en la estación lluviosa) y 1 577 organismos de E. argenteus (> 50% en la estación seca) fueron recolectados durante el período de estudio. Se determinó la relación peso-longitud (RPL) como: P = 8.323E-03 Lt 2.92 en E. argenteus y P = 7.314E-03  Lt2.92 en E. gula.  Para E. argenteus, los parámetros de crecimiento de la ecuación de crecimiento de von Bertalanffy (ECVB) fueron: L∞ = 13.65 cm,  k = 0.54 año-1 y t0 = - 0.37 años; mientras que para E. gula fueron: L∞ = 12.60 cm, k = 0.68 año-1 y t0 = - 0.28 años. La mortalidad natural en E. gula fue 1.50 año-1 y en E. argenteus fue 1.9 año-1. Este estudio presenta la primera estimación para ambas especies de los modelos de crecimiento, el índice del desempeño de crecimiento y la mortalidad natural para la península de Yucatán, lo que es relevante para la adecuada implementación de medidas de conservación de E. gula y E. argenteus en una valiosa zona costera de la península de Yucatán.

scholarly journals POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA

2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Lake Ecosystems ◽  
Exploitation Rate ◽  
Length Frequency Data

The Malayan leaf fish or locally named as kepor (Pristolepis grooti) is one of important biotic components in Ranau Lake ecosystems. This study aimed to estimate population dynamic and exploitation rate of kepor in Ranau Lake, South Sumatera. The population parameters are estimated based on length frequency data which were collected in March to October 2013. Growth parameters and fishing mortality rates were calculated using FiSAT software package. The results showed that kepor’s growth was negative allometric, which tended to gain length faster than weight. Kepor population was dominated (42%) by individual length of 10.0 to 11.0 cm. Predicted length infinity (L) was 17.28 cm with high value of growth rates (K) of 1.4 year-1. The natural mortality rate (M) is 2.57 year-1, the fishing mortality rate (F) is 5.36 year-1 and total mortality rate (Z) is 7.93 year-1. The exploitation rate of Malayan leaf fish in Ranau Lake (E = 0.68 year-1) has passed the optimum score.  

scholarly journals DINAMIKA POPULASI LOBSTER PASIR (Panulirus homarus Linnaeus, 1758) DI PERAIRAN PALABUHANRATU, JAWA BARAT

2018 ◽  
Vol 23 (3) ◽  
pp. 215 ◽  
Author(s):  
Zairion Zairion ◽  
Nefi Islamiati ◽  
Yusli Wardiatno ◽  
Ali Mashar ◽  
Rudi Alek Wahyudin ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Spiny Lobster ◽  
Total Sample ◽  
Optimum Level ◽  
Length Frequency ◽  
Recruitment Pattern ◽  
Exploitation Rate ◽  
Lobster Fishery ◽  
Average Size ◽  
Length Frequency Analysis

Dinamika populasi merupakan aspek penting sebagai dasar pengelolaan perikanan dan informasi tentang aspek tersebut pada lobster pasir masih minim di perairan Palabuhanratu. Tujuan penelitian ini adalah mengkaji aspek pertumbuhan, pola rekrutmen, mortalitas dan laju eksploitasi lobster pasir (Panulirus homarus) di perairan Palabuhanratu. Penelitian ini dilakukan periode Juni 2015-Mei 2016 dengan metode sensus. Lobster pasir hasil tangkapan jaring insang dasar dengan jumlah total sampel 483 ekor mempunyai panjang karapas antara 28-100 mm. Pola pertumbuhan berdasarkan hasil regresi linear memperlihatkan allometrik negatif. Hasil analisis menggunakan metode ELEFAN I (Electronic Length Frequency Analysis) menunjukan koefisien pertumbuhan lobster pasir jantan (K = 0,29 per tahun), lebih kecil dibandingkan dengan betina (K = 0,40 per tahun). Rekrutmen terindikasi dua puncak dalam setahun: yaitu pada Februari-Mei dan September-Oktober). Laju mortalitaskarena penangkapan (F) mencapai 1,9-2,2 kali laju mortalitas alami (M). Nilai Lc<Lrmemperlihatkan lobster pasir sudah tertangkap sebelum mencapaiukuran rata-rata mengerami telur atau ukuran kematangan reproduktif. Laju eksploitasi lobster pasir mencapai 32-38% di atas laju eksploitasi optimum, sehingga lobster pasir sudah mengalamieksploitasi yang berlebih.Population dynamics is an important aspect as basic of fisheries management and little information of this aspect for spiny lobster fishery in Pelabuhanratu waters. This research aims to evaluate of growth aspects, recruitment pattern, mortality, and exploitation rate of scalloped spiny lobster (Panulirus homarus) in Palabuhanratu waters. This research was conducted in June 2015 until May 2016 using census method. The size of P. homarus captured using bottom gill-net with total sample 483 specimen was between 28-100 mm carapace lengths (CL). Linear regression showed that growth pattern was negative allometric. The growth coefficient of male (K = 0.29 per year) was found smaller than female (K = 0.40 per year) based on ELEFAN I (Electronic Length Frequency Analysis) method. Recruitment seems to be accrued twice peaks a year (February to May and September to October) and the highest was at February to May. Fishing mortality (F) reached 1.9 to 2.2 times of natural mortality (M). The LcÂLr value showed that female has been caught before reached the average size of bearing eggs or reproductive maturity size. The exploitation rate of spiny lobsters reaches 32-38% above optimum level. This study suggests that the spiny lobster fishery in Palabuhanratu in the state of overexploitation.

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