scholarly journals Population dynamics of notopterus notopterus (Pallas, 1769) from the Kaptai reservoir of Bangladesh

2015 ◽  
Vol 12 (2) ◽  
pp. 112-122 ◽  
Author(s):  
M Golam Mustafa ◽  
S Singha ◽  
MR Islam ◽  
Nayan Mallick
Keyword(s):  
Population Analysis ◽  
Relative Yield ◽  
Total Mortality ◽  
Natural Mortality ◽  
Total Catch ◽  
Instantaneous Rate ◽  
Virtual Population ◽  
Exploitation Rate ◽  
Two Peaks ◽  
Notopterus Notopterus

Population parameters of Notopterus notopterus (Pallas, 1769) from length-frequency data collected from Kaptai Reservoir of Rangamati, Bangladesh from January, 2013 to December, 2013 were calculated by using FiSAT software. The asymptotic total length (L?) and growth coefficient (K) were estimated to be 34.91cm and 0.38 y?1respectively. The instantaneous rate of natural mortality (M), fishing mortality (F) and total mortality (Z) were estimated to be as 0.91 y?1, 0.28 y?1and 1.19 y?1 respectively. The value of exploitation rate (E) was found to be 0.24 which clearly pointed toward moderate or less fishing pressure (E<0.50) of N. notopterus in the Kaptai reservoir of Bangladesh. The recruitment of the species was found throughout the year with two peaks - one from March-April; and another from May- June. Virtual population analysis (VPA) estimated that the maximum numbers of N. notopterus were caught between 10.50 cm to 32.50 cm with maximum F value (0.80 y?1) in the mid length of 18.30 cm. During the year 2013 the total catch of N. notopterus was found to be 664.5 MT, which contributed about 7.78% of the total catch of Kaptai Lake. Relative yield per recruit (Y’/R) and biomass per recruit (B’/R) suggested that the natural mortality should be reduced to 0.91 y?1 by proper management to obtain a maximum sustainable exploitation rate (Emax= 0.828) for the species in the reservoir. DOI: http://dx.doi.org/10.3329/sja.v12i2.21923 SAARC J. Agri., 12(2): 112-122 (2014

scholarly journals Aspects of Population Dynamics of Tiger Tooth Croaker, Otolithes ruber (Bloch and Schneider, 1801) from Northwest Arabian Gulf, Iraq

2021 ◽  
pp. 9-21
Author(s):  
Abdul-Razak M. Mohamed ◽  
Ali H. Al-Hassani
Keyword(s):  
Population Dynamics ◽  
Population Analysis ◽  
Arabian Gulf ◽  
Relative Yield ◽  
Total Mortality ◽  
Reference Points ◽  
Virtual Population Analysis ◽  
Virtual Population ◽  
Exploitation Rate ◽  
Otolithes Ruber

The present study consists of the growth, mortality, relative yield recruit and virtual population analysis of tigertooth croaker, Otolithes ruber from Iraqi marine waters, northwest Arabian Gulf between February 2020 and January 2021. Analysis of population dynamics employed methods fitted in FiSAT II software using pooled length-frequencies. A total of 3835 individuals of O. ruber ranged from 17.0 to 60.0 cm have been collected. The exponent (b) of the length-weight relationship was found to be 2.755. The von Bertalanffy growth parameters (L∞ and K) were estimated as 68.5 cm and 0.36, respectively, while the growth performance index (Ø') was 3.228.  The total mortality (Z) was calculated as 1.10, while the natural and fishing mortality rates were 0.69 and 0.41, respectively, and the current exploitation rate (Ecurrent) was 0.38. Fish were recruited to the fishery at a mean size of L50= 20.55 cm. The recruitment pattern of O. ruber was continuous throughout the year with two major peaks. The analysis of yield-per-recruit (Y/R’) indicates that the current exploitation rate was below the biological target reference points (E0.1 = 0.40 and Emax= 0.53), refer to the stock of O. ruber is underexploited. The 27 cm length group was more vulnerable to fishing and more harvested according to virtual population analysis. sLength at first capture was higher than the length at first maturity of the species in the region. For management purposes, more yields could be obtained by increasing the mesh sizes of the nets employed in the fishing of the species. 

scholarly journals Population dynamics of the mullet fish, Rhinomugil corsula (Hamilton, 1822), in the Sitakunda coast of the Bay of Bengal

2019 ◽  
Vol 47 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Syeda Ismat Ara ◽  
MA Azadi ◽  
Munira Nasiruddin ◽  
Aftab Hossain ◽  
MG Mustafa
Keyword(s):  
Population Dynamics ◽  
Bay Of Bengal ◽  
Relative Yield ◽  
Total Mortality ◽  
Recruitment Pattern ◽  
Instantaneous Rate ◽  
A Minor ◽  
Two Peaks ◽  
Yield Per Recruit ◽  
Rhinomugil Corsula

Population dynamics of the mullet species, Rhinomugil corsula, was studied, using FiSAT-II program, with the length-frequency data of 2480 fish specimens. The asymptotic length (L∞) and growth coefficient (K) of this fish were estimated to be 31.4 cm and 1.0/year, respectively. The instantaneous rate of natural mortality (M), fishing mortality (F) and total mortality (Z) were estimated to be 1.73, 1.20 and 2.93, respectively. The recruitment pattern of the species was prolonged with two peaks, major peak during June to December and a minor peak during January to April. The L25, L50 and L75 were found to be 8.61, 10.42 and 12.23 cm, respectively. The relative yield per recruit (Yʹ/R) and biomass per recruit (Bʹ/R) were 0.751 and 1.731, respectively. The value of exploitation (E) was found to be 0.41 which indicated that R. corsula was not over fished (E > 0.50) in the study area. The maximum exploitation (Emax) value was 0.55. The growth performance index (ϕ´ = 2.99) of R. corsula in the Sitakunda coast of the Bay of Bengal was found to be moderate. Bangladesh J. Zool. 47(2): 305-314, 2019

Virtual Population Analysis (VPA) Equations for Nonhomogeneous Populations, and a Family of Approximations Including Improvements on Pope's Cohort Analysis

1986 ◽  
Vol 43 (12) ◽  
pp. 2406-2409 ◽  
Author(s):  
Alec D. MacCall
Keyword(s):  
Mortality Rate ◽  
Population Analysis ◽  
Seasonal Pattern ◽  
Cohort Analysis ◽  
Natural Mortality ◽  
Close Approximation ◽  
Virtual Population Analysis ◽  
Virtual Population ◽  
Special Case

A set of "backward" virtual population analysis (VPA) equations relates catch (Ct) from continuous fishing between times t and t + 1 to population n size (Nt, Nt+1) when a portion of the stock is unavailable to fishing. The usual VPA equations become a special case where the entire stock is available (i.e. the stock is homogeneous). A close approximation to the VPA equations is Nt = Nt+1 exp(M) + CtM/(1 − exp(−M)), which has properties similar to Pope's "cohort analysis" and is somewhat more accurate in the case of a continuous fishery, especially if the natural mortality rate (M) is large. Much closer simple approximations are possible if the seasonal pattern of catches is known.

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 Estimation of the age-specific rate of natural mortality for Shetland sandeels

2004 ◽  
Vol 61 (2) ◽  
pp. 159-164 ◽  
Author(s):  
R.M. Cook
Keyword(s):  
Survey Data ◽  
Population Analysis ◽  
Mean Value ◽  
Specific Rate ◽  
Natural Mortality ◽  
The North ◽  
Virtual Population ◽  
Stock Assessments ◽  
The North Sea ◽  
The Mean

Abstract It is generally difficult to obtain reliable direct estimates of natural mortality, M, from conventional fisheries data and stock assessments. However, as a result of the closure of the Shetland sandeel (Ammodytes marinus) fishery from 1991 to 1994 and in the absence of any significant fishery in other years, research vessel survey data offer a rare opportunity to obtain estimates of M directly. A model is described that assumes that M can be decomposed into an age effect and year effects. Application of the model to the survey data produces values of M that decline from 2.1 for 0-group fish to 0.6 at age 2. There is some indication of an increase for ages 4 and older. Although there does not appear to be an overall trend in the mean value of M for the period 1985–1999, the annual values change by up to 50%. The values calculated from the model are in line with estimates obtained for the North Sea from multispecies virtual population analysis (MSVPA).

scholarly journals PARAMETER POPULASI DAN BIOLOGI REPRODUKSI IKAN BENTONG (Selar crumenophthalmus) DI PERAIRAN KWANDANG,GORONTALO UTARA

2015 ◽  
Vol 6 (2) ◽  
pp. 111 ◽  
Author(s):  
Ria Faizah ◽  
Lilis Sadiyah ◽  
Tuti Hariati
Keyword(s):  
Total Mortality ◽  
Maturity Stage ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Population Parameters ◽  
Length Frequency ◽  
Exploitation Rate ◽  
Length Frequency Data ◽  
Pelagic Fisheries

Perairan Kwandang merupakan salah satu basis utama perikanan pelagis kecil di perairan laut Sulawesi. Salah satu jenis yang banyak dimanfaatkan adalah ikan bentong (Selar crumenophthalmus). Penelitian ini bertujuan untukmenduga parameter populasi, tingkat pemanfaatan (E), dan biologi reproduksi dari ikan bentong. Data panjang cagak dikumpulkan dari PP Kwandang dari bulan Januari hingga November 2012. Pendugaan parameter populasi dilakukan dengan menggunakan metode Bhattacharya dengan bantuan software FISAT II Hasil analisis menunjukkan bahwa laju pertumbuhan (K) sebesar 0,76 per tahun dengan L”=24,7 cm. Laju kematian total (Z) sebesar 2,63 per tahun, dengan laju kematian alamiah (M) sebesar 1,28 per tahun, laju kematian akibat penangkapan (F) sebesar 1,3 per tahun dan laju pemanfaatan 0,51. Tingkat pemanfaatan ikan bentong sudah relatif optimum. Rasio jenis kelamin ikan bentong jantan dan betina adalah 1: 1,02. TKGI paling banyak ditemukan. Musim pemijahan ikan bentong diduga terjadi pada bulan November dan Desember.The Kwandang waters is one of the main base for small pelagic fisheries in Sulawesi sea. Bigeye scad (Selar crumenophthalmus) is one of species from small pelagic is exploited. The objectives of the research was to estimate the population parameters, exploitation rate and reproductive biology of bigeye scad. Length frequency data were collected from PP Kwandang, from January November 2012. Estimation of population parameters of bigeye scad used FISAT II method. The results showed that growth rate as follows (K) = 0,76 year-1 , L”=24,7 cm. Total mortality rate (Z) = 2,63 year-1, with natural mortality (M) = 1, year-1 and fishing mortality (F) = 1,3 year-1 and exploitation rate (E)=0,51. The exploitation rate are already optimum. Sex ratio of male and female are 1:1,02. The most commonly founded is Gonado Maturity Stage of I. The spawning season of bigeye scad estimated was November and December

scholarly journals DINAMIKA POPULASI IKAN GABUS (Channa striata) DI RAWA DANAU PANGGANG, KALIMANTAN SELATAN

2018 ◽  
Vol 14 (1) ◽  
pp. 16
Author(s):  
Dini Sofarini ◽  
Mohammad Mahmudi ◽  
Asus Maizar S. Hertika ◽  
Endang Yuli Herawati
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Population Dynamic ◽  
Growth Pattern ◽  
Total Mortality ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishery Resource ◽  
Exploitation Rate ◽  
Channa Striata

The province of South Kalimantan has the largest peat swamp that is named Danau Panggang Swamp with an area of 5,390.7 Ha. This swamp has ecological, economic and potential functions of a large fishery resource. The purposes of this study are to evaluate the exploitation rate of Snake Head Fish (Channa striata) in Danau Panggang Swamp, by population dynamic analysis using FISAT program of Von Bertalanffy method.  The results showed that the growth pattern of Snake Head Fish (Channa striata) has the tendency to grow negative allometric with 63.4 cm of long infifer (L¥), growth rate (k) 0.15 per year, theoretical age at the time of the fish is equal to 0 (t0) is -1.48257 years. While the natural mortality rate (M) was 0.43, the mortality rate due to catch (F) of 0.69/year and the total mortality rate  (Z) of 1.12/year, and the rate of exploitation value E = 0.62.  These results indicated that the exploitation rate of Head Snake Fish (Channa striata) in Danau Panggang swamp has a tendency to overfishing.

scholarly journals Analisis dinamika populasi ikan selar kuning (Selaroides leptolepis) dalam upaya pengelolaan sumberdaya ikan pelagis kecil di perairan Bintan, Provinsi Kepulauan Riau

DEPIK ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 428-434
Author(s):  
Septiyawati Septiyawati ◽  
Muhammad Fauzi ◽  
Deni Efizon
Keyword(s):  
Mortality Rate ◽  
Total Mortality ◽  
Natural Mortality ◽  
Salted Fish ◽  
Fisheries Resources ◽  
Exploitation Rate ◽  
Raw Fish ◽  
Pelagic Fisheries

This raw fish is used as fisheries products such as salted fish, grilled fish, fishmeal and surimi. This study aims to analyze mortality and recruitment of yellowstipe scad (Selaroides leptolepis) and the information about management of small pelagic fisheries resources in Bintan Waters. This research was carried out in February-June 2019 at the Barek Motor Fish Landing Area (TPI) with fishing areas in Bintan waters. The number of fish studied was 2.550 with a length of 102-215 mm and a weight of 15-102 gr. The highest recruitment peak occurred in Mei of 18.11% and June of 19.48%. The highest and lowest condition factors are 0.83 and 1.09. The total mortality rate (Z) of yellow strait fish is 4.61 per year with a natural mortality rate (M) of 1.66 per year and the capture mortality rate of 2.95 per year so that the exploitation rate is 0.63. The death of yellowstipe scade in the Bintan Sea most of the caused by fishing activities (F) of 2.95 per year.Keywords:Yellowstipe scad Bintan WatersRecrutmentCondition factorsMortalityABSTRAKIkan selar kuning merupakan salah satu jenis ikan ekonomis penting. Ikan ini banyak dimanfaatkan sebagai bahan baku produk olahan perikanan seperti ikan asin, ikan bakar, pindang, tepung ikan dan surimi. Penelitian ini bertujuan untuk menganalisis, mortalitas dan rekrutmen ikan selar kuning (Selaroides leptolepis) dan informasi tentang pengelolaan sumberdaya ikan pelagis kecil di Perairan Bintan. Penelitian ini telah dilaksanakan bulan Februari-Juni 2019 di Tempat Pendaratan Ikan (TPI) Barek Motor dengan wilayah penangkapan di perairan Bintan. Jumlah ikan yang diteliti 2.550 ekor dengan panjang 102-215 mm dan berat 15-102 gr. Puncak rekrutmen tertinggi terjadi bulan Mei sebesar 18,11% dan Juni sebesar 19,48%,. Nilai tertinggi dan terendah faktor kondisi yaitu 0,82 dan 1,09. Laju mortalitas total (Z) ikan selar kuning 4,61 per tahun dengan laju mortalitas alami (M) 1,66 per tahun dan laju mortalitas penangkapan 2,95 per tahun sehingga diperoleh laju eksploitasi 0,63. Kematian ikan selar kuning di laut Bintan sebagian besar diakibatkan oleh aktivitas penangkapan (F) sebesar 2,95 per tahun.Kata kunci:Ikan selar kuning Perairan Bintan Rekrutmen Faktor kondisi Mortalitas

scholarly journals ANALISIS PERTUMBUHAN DAN LAJU EKSPLOITASI IKAN TONGKOL ABU-ABU, Thunnus tonggol (Bleeker, 1851) DI PERAIRAN LAUT JAWA

2018 ◽  
Vol 10 (2) ◽  
pp. 95 ◽  
Author(s):  
Yoke Hany Restiangsih ◽  
Thomas Hidayat
Keyword(s):  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Research Activity ◽  
Gill Net ◽  
Exploitation Rate ◽  
Java Sea ◽  
Harvest Strategy ◽  
Weight Data ◽  
Longtail Tuna

Tongkol abu-abu atau longtail tuna (Thunnus tonggol) salah satu jenis ikan tuna neritik sebagai target penangkapan armada pukat cincin, jaring isang, dan pancing di Laut Jawa. Penelitian ini bertujuan untuk mengetahui parameter pertumbuhan, umur dan mortalitas ikan tongkol abu-abu untuk penyusunan strategi pengelolaannya. Pengumpulan data frekuensi panjang dan bobot ikan dilakukan di Pelabuhan Perikanan Nusantara (PPN) Pekalongan pada Januari – Nopember 2014. Hasil penelitian menunjukkan hubungan panjang-bobot ikan tongkol abu-abu bersifat isometrik dan indek kecepatan pertumbuhan 3,46/tahun. Ikan dapat tumbuh hingga mencapai panjang asimtotik (L) = 85 cm dengan laju pertumbuhan (K) sebesar 0,4/tahun. Umur teoritis pada saat panjang ikan sama dengan nol (t0) adalah 0,046 tahun. Umur maksimal diduga 15 tahun. Mortalitas alami (M) sebesar 0,61/tahun, mortalitas karena penangkapan (F) 1,01/tahun, mortalitas total (Z) 1,62/tahun. Tingkat eksploitasi (E) sebesar 0,59 berarti bahwa pemanfaatan ikan tongkol abu-abu di Laut Jawa cenderung sudah penuh (fully exploited).Longtail tuna as one of neritic tuna species are commonly caught by purse seine, gill net and hand line in java sea.. This research activity aims to determine population parameters i.e. growth, mortality and its exploitation rate that can contribute to strengthen database on preparation its harvest strategy. The Collecting of length and weight data were conducted at Pekalongan fishing port during period of January to November 2014. The Long-weigth relationship was isometric and growth performance index was 3.46/year. The asymptotic length rate (L) was 85 cmFL, growth rate (K) was 0.4/year and zero age (t0) was 0.046 year. This length is reached allegedly at the 15 years age. Natural mortality (M) was 0.6/year, fishing mortality (F) was 1.01/year, total mortality (Z) was 1.62/yera. The exploitation rate (E) was 0.59, it means exploitation of longtail tuna in the Java Sea tend to highly exploited.

scholarly journals Evaluación de la pesquería de Lutjanus peru (Pisces: Lutjanidae) de . Guerrero, México

1969 ◽  
pp. 571-580
Author(s):  
Apolinar Santamaría ◽  
Ernesto A Chávez
Keyword(s):  
Growth Model ◽  
Population Analysis ◽  
Small Fish ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Cohort Size ◽  
Virtual Population ◽  
Von Bertalanffy Growth Model ◽  
Parameter Values ◽  
Yield Per Recruit

Red snapper (Lutjanus peru) fishery was analyzed from landings and catch records. Stock age structure was reconstructed after the parameter values of the von Bertalanffy growth model, the length-weight relationship, ages and the natural mortality coefficient through each of nine years of cateh records. The Pisat software package was applied to assess population parameters, whose estimates are, for the von Bertalanffy growth model, K = 0. 1 442 to 0.38; lo = -0.2; L = 87 cm; W = 9.4 Kg, and the natural mortality coefficient (M) afier several methods (0. 14 to 0.38). Cohort size was assessed by the virtual population analysis (VPA), estlmating population size in 5.2* 1 06 fish with a biomass of 8 454 tonnes. Current fishing mortality P, ranges from 0.06 to 1 . 1 3, depending upon the chosen M value; according to this, when the M value used is low, the results suggest that the stock is nnderexploited, and vice versa. The yield per recruit model applied suggests improvements to the management strategy. The model indicates recruit overfishing because very small fish are the main target (te

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