scholarly journals GROWTH AND EXPLOITATION STATUS (Channa striata Bloch, 1793) IN LUBUK LAMPAM FLOODPLAINS, SOUTH SUMATERA

2013 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
Zulkarnaen Fahmi ◽  
Syarifah Nurdawati ◽  
Freddy Supriyadi
Keyword(s):  
Relative Yield ◽  
Total Mortality ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Future Plan ◽  
Channa Striata ◽  
Exploitation Status ◽  
Yield Per Recruit

Due to the economic importance of C. striata in Lubuk Lampam floodplains (Indonesia), this study is aimed to estimate the biological and population parameters required for proposing a future plan to sustain and manage this valuable fish resource. The growth, mortality and explotation ratio of <em>Channa striata</em> estimated by employing FiSATProgramme are reported. The parameters of Von Bertalanffy growth model of 1,529 sample fishes were estimated as K= 0.36/ year, L” = 72.98 cm and to = -0.52 year. The coefficients of total mortality (Z), natural mortality (M) and fishing mortality (F) were 1.72, 0.73 and 0.99 year-1 respectively. Relative yield per recruit analysis shows that the presentexploitation rate (E) was 0.58. Yield per recruit can be maximized at the exploitation ratio of 0.5 and Lc/Linf values of 0.3. The Yield per recruit and biomass per recruit models indicated that, the fisheries status of <em>C. striata</em> in Lubuk Lampam floodplains exceed the limit reference point (Fmax), thus stock of this species in Lubuk Lampam floodplains is indicated being driving down.Reduction in fishing effort and increase number of selective fishing gears are suggested to sustain the fishery of <em>Channa striata</em> in Lubuk Lampam floodplains.

scholarly journals BEBERAPA PARAMETER POPULASI UDANG PUTIH (Penaeus merguiensis de Mann) DI PERAIRAN TARAKAN, KALIMANTAN UTARA

2017 ◽  
Vol 9 (2) ◽  
pp. 85
Author(s):  
Umi Chodrijah ◽  
Ali Suman
Keyword(s):  
Mortality Rate ◽  
Total Mortality ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Spawning Period ◽  
Exploitation Rate ◽  
First Maturity ◽  
Penaeus Merguiensis

Tingkat eksploitasi udang putih (Penaeus merguiensis) sangat intensif. Hal ini terindikasi dengan hasil tangkapan udang di WPP-NRI 716 selama 9 tahun terakhir meningkat. Tujuan penelitian ini untuk mengkaji beberapa parameter populasi dan aspek biologi udang putih di perairan Tarakan. Data panjang karapas dan tingkat kematangan gonad udang putih dikumpulkan dari tempat pendaratan udang di Selumit Pantai, Tarakan, Kalimantan Utara pada Januari sampai dengan November 2016. Pendugaan parameter populasi dengan aplikasi model analisis menggunakan program ELEFAN 1. Hasil penelitian menunjukkan rata-rata ukuran udang putih pertama kali tertangkap (Lc) pada panjang karapas 32,51 mm dan rata-rata ukuran pertama kali matang gonad 33,58 mm. Puncak musim pemijahan terjadi pada Maret dan Agustus. Laju pertumbuhan (K) sebesar 1,33 per tahun (betina) dan 1,55 per tahun (jantan). Laju kematian total (Z) sebesar 7,5 per tahun (betina) dan 8,85 per tahun (jantan), laju kematian alamiah (M) sebesar 1,82 per tahun (betina) dan 2,16 per tahun (jantan) serta laju kematian akibat penangkapan (F) sebesar 5,68 per tahun (betina) dan 6,69 per tahun (jantan). Laju pengusahaan (E) udang putih di perairan Tarakan adalah sebesar 0,76 per tahun. Hal ini menunjukkan tingkat pemanfaatan udang putih telah mengalami lebih tangkap (overfishing). Kondisi ini menggambarkan perlunya dilakukan pengurangan upaya sekitar 52 %.  The banana prawn (Penaeus merguiensis) have been exploited intensively. For instance, within nine years the number of shrimp production in FMA 716 increased dramatically. This research aims to identify the some population parameters of banana prawn in the Tarakan waters. This research was carried out from January to November 2016. Data were analyzed using the analytical model application with ELEFAN I. The result showed that the length at first capture (Lc) of banana prawn was 32,51 mmCL and the length at first maturity (Lm) was 33,58 mm CL. The peak season of spawning period was indicated on March and August. The growth rate (K) was 1,33 /year (female) and 1.55/year (male). Total mortality rate (Z) was 7.5/year (female) and 8,85/year (male), natural mortality rate (M) rate was 1.82/year (female) and 2.16/year (male) and fishing mortality rate ( F) were 5.68/ year (female) and 6.69/year (male). The exploitation rate (E) of banana prawn in the Tarakan waters was 0.76 per year. Therefore, level of existing fishing effort of the banana prawn should reduced about 52 % in the next year.

scholarly journals Growth Pattern, Mortality and Exploitation Rate of the Giant African Threadfin, Polydactylus quadrifilis (Cuvier, 1829) from Ebrié Lagoon (Potou Sector, Côte d’Ivoire)

2020 ◽  
pp. 33-42
Author(s):  
Théophile Aké Bédia ◽  
Bakari Coulibaly ◽  
Yao Aristide Konan ◽  
Essetchi Paul Kouamelan ◽  
Valentin N’douba
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Growth Pattern ◽  
Total Mortality ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Exploitation Rate ◽  
First Maturity

The study evaluated some population parameters of Polydactylus quadrifilis within Ebrié lagoon (Potou sector). Samples were obtained using artisanal gillnet fishery from April 2004 to March 2006. A total of 741 individuals of P. quadrifilis ranged from 11 to 70 cm were examined. Population parameters were estimated where asymptotic length (L∞) was found 60 cm, growth rate (K) 0.33 per year, the longevity (T max) 9.09 years, and growth performance index (Φ′) 3.06. The length at first capture (Lc50 = 10.60 cm) was lower than the length at first maturity (Lm50 = 40 cm). Total mortality rate (Z) was calculated as 1.10 per year including natural mortality and fishing mortality. The exploitation rate (E=0.36) was found to be less than the maximum exploitation rate (E max = 0.44) and indicated that P. quadrifilis is not overexploited. The current exploitation rate should be maintained by sustainable fisheries measures including monitoring of fishing effort.

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

Yield-per-recruit and egg-per-recruit analyses of the Omani abalone, Haliotis mariae

1995 ◽  
Vol 46 (3) ◽  
pp. 663 ◽  
Author(s):  
SA Shepherd ◽  
JL Baker ◽  
DW Johnson
Keyword(s):  
Mortality Rate ◽  
Sexual Maturity ◽  
Egg Production ◽  
Arabian Sea ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Northern Arabian Sea ◽  
Size At Sexual Maturity ◽  
Yield Per Recruit

The fecundity, size at sexual maturity, sex ratios and total mortality of Haliotis mariae on the Dhofar coast of the northern Arabian Sea were measured. These data, and estimates of the growth rate, were used for yield-per-recruit and egg-per-recruit analyses. Maximum yields occur at 3+ to 4+ years of age, depending on the natural mortality rate chosen. At the present age at first capture egg production levels are 2-29% of the unfished stock, depending on estimates of the fishing mortality rate and the natural mortality rate, and are considered to be far too low to maintain recruitment. At 40% egg production, of the maximum possible the age at first capture is 4 to 4.5 years, i.e. 105-115 mm shell length, depending on site.

scholarly journals Yield per recruit of the peacock bass Cichla monoculus (Spix and Agassiz, 1831) caught in Lago Grande at Manacapuru (Amazonas – Brazil)

2014 ◽  
Vol 74 (1) ◽  
pp. 226-230 ◽  
Author(s):  
CP Campos ◽  
CEC Freitas
Keyword(s):  
Growth Parameters ◽  
Fishing Effort ◽  
Maximum Sustainable Yield ◽  
Minimum Size ◽  
Small Scale ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Yield Per Recruit ◽  
Peacock Bass ◽  
Actual Size

We evaluated the stock of peacock bass Cichla monoculus caught by a small-scale fishing fleet in Lago Grande at Manacapuru. The database was constructed by monthly samplings of 200 fish between February 2007 and January 2008. We measured the total length (cm) and total weight (gr) of each fish. We employed previously estimated growth parameters to run a yield per recruit model and analyse scenarios changing the values of the age of the first catch (Tc), natural mortality (M), and fishing mortality (F). Our model indicated an occurrence of overfishing because the fishing effort applied to catch peacock in Lago Grande at Manacapuru is greater than that associated with the maximum sustainable yield. In addition, the actual size of the first catch is almost half of the estimated value. Although there are difficulties in enforcing a minimum size of the catch, our results show that an increase in the size of the first catch to at least 25 cm would be a good strategy for management of this fishery.

scholarly journals Effects of spatial heterogeneity in growth and fishing effort on yield-per-recruit models: an application to the US Atlantic sea scallop fishery

2015 ◽  
Vol 73 (4) ◽  
pp. 1062-1073 ◽  
Author(s):  
Samuel B. Truesdell ◽  
Deborah R. Hart ◽  
Yong Chen
Keyword(s):  
Spatial Heterogeneity ◽  
Spatial Data ◽  
Egg Production ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Sea Scallop ◽  
The Us ◽  
The Impact ◽  
Yield Per Recruit

Abstract Conventional yield-per-recruit (Y/R) and spawning-stock biomass-per-recruit (SSB/R) models make no allowance for spatial heterogeneity in fishing mortality, natural mortality, or growth across the stock area, although variability in these processes can affect model results. For example, areas with higher growth and/or lower natural mortality rates should be fished at a lower rate to maximize Y/R; however, these areas may be especially attractive to fishers and are often fished harder. Here, Y/R and SSB/R models are developed that simultaneously account for spatial heterogeneity in growth and fishing effort. These models are applied to the US Atlantic sea scallop (Placopecten magellanicus) fishery. The spatial variability in growth uses depth-integrated models from the literature and variability in effort is based on, alternatively, uniform, observed, and relative-optimal spatial harvesting distributions. The observed effort patterns are derived from vessel monitoring system positions, and illustrate one application for these widely collected but underutilized spatial data. In this example, the distribution of observed fishing effort reduces Y/R compared with the relative-optimal, or the uniform effort distribution implicitly assumed by conventional Y/R analysis. SSB/R was in some cases considerably higher under the relative-optimal distribution of effort than when calculated using observed or uniform effort patterns. Such more realistic spatially integrated Y/R and SSB/R models can help to evaluate the impact of effort patterns on fishery yield and stock egg production. These models demonstrate that the spatial distribution of effort can be as important as the overall average fishing mortality when managing fisheries to optimize Y/R, SSB/R, and yield.

scholarly journals Ecology and population dynamics of silver catfish, Chrysichthys nigrodigitatus (Siluriformes: Claroteidae), of the Cross River, Nigeria

2020 ◽  
Vol 19 (1) ◽  
pp. 71-82
Author(s):  
Daniel Ama-Abasi ◽  
Edak Aniedi Uyoh
Keyword(s):  
Total Mortality ◽  
Single Species ◽  
Fishing Effort ◽  
Catch Rate ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Cross River ◽  
Exploitation Rate ◽  
The Cross

Chrysichthys nigrodigitatus forms the most commercially important freshwater single species fishery in the Cross River, Nigeria. Studies were  conducted on the dynamics of the exploited population of the species and the influence of rainfall on its catch rate. The objectives were to assess the level of exploitation and impacts of rainfall on its catch rate. A time series of length frequency and meteorological parameters was conducted. Length frequency data were analyzed using FiSAT software to estimate population parameters. The asymptotic length, Lı was 105 cm, growth constant (K) was 0.68 year-1, total mortality (Z) was 2.48 year-1, Natural mortality (M) was 0.99 year-1 and fishing mortality (F) was 1.49 year-1. The exploitation rate was 0.60 year-1, indicating overfishing. Natural mortality accounted 40% of the total mortality, presenting a worrisome trend in the fishery. There was a correlation between rainfall and catch rate, which increased at the onset of rains but decreased at the peak of the rains due to increased depth of the river. For management purposes, it is recommended that the fishing effort should be reduced by the regulation of the number of boat-days; for conservation, domestication of the species should be adopted as an adaptation to climatic influence. Keywords: Freshwater Catfish, Fishing Mortality, Exploitation Rate, Overfishing, Rainfall Impact, Niger Delta.

scholarly journals Estimating fishing and natural mortality rates, and catchability coefficient, from a series of observations on mean length and fishing effort

2017 ◽  
Vol 75 (2) ◽  
pp. 610-620 ◽  
Author(s):  
Amy Y Then ◽  
John M Hoenig ◽  
Quang C Huynh
Keyword(s):  
Mortality Rate ◽  
Total Mortality ◽  
Fishing Effort ◽  
Residual Variance ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Norway Lobster ◽  
Rapid Growth Rate ◽  
Complex Models ◽  
The Mean

Abstract Gedamke and Hoenig (2006) (Transactions of the American Fisheries Society, 135: 476–487) developed a non-equilibrium version of the Beverton and Holt estimator of total mortality rate, Z, based on mean length and thereby increased the usefulness of length-based methods. In this study, we extend their model by replacing period-specific Z parameters with the year-specific parameterization Zy = qfy + M where q is the catchability coefficient, fy is the fishing effort in year y, F (=qf) is the fishing mortality rate, and M is the natural mortality rate. Thus, the problem reduces to estimating just three parameters: q, M and residual variance. We used Monte Carlo simulation to study the model behaviour. Estimates of q and M are highly negatively correlated and may or may not be reliable; however, the estimates of corresponding Z’s are more precise than estimates of F and are generally reliable, even when uncertainty about the mean lengths is high. This length-based method appears to work best for stocks with rapid growth rate. Contrast in effort data may not be necessary for reliable estimates of Z’s. This approach forms a bridge between data-limited models and more complex models. We apply the method to the Norway lobster Nephrops norvegicus stock in Portugal as an example.

scholarly journals Population parameters and exploitation level of striped snakehead, Channa striata (Bloch, 1793) in Aopa Swamp, Southeast Sulawesi

AQUASAINS ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 829
Author(s):  
Nurtini Bahrin ◽  
La Sara La Sara ◽  
Asriyana Asriyana
Keyword(s):  
Growth Pattern ◽  
Equation Model ◽  
Maximum Length ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Population Parameters ◽  
Growth Coefficient ◽  
Individual Fish ◽  
Fish Samples ◽  
Channa Striata

Striped snakehead is one of the important economical fish in Aopa Swamp waters. Research on population parameters and exploitation level of striped snakehead was conducted from November 2018 to January 2019. The objective of this research was to analyze population parameters and exploitation level of  striped snakehead in the Rawa Aopa waters in Southeast Sulawesi. Fish samples were caught using a fishing trap used by fishermen. A total of 449 individual fish were caught with ranging 20.0-47.0 cm in length and 59.0-994.0 g in weight. Striped snakehead has an isometric growth pattern (b=3.08 ; r=0.96, R2=0.92) with the equation model W=6.10-3L3,08. Striped snakehead reaches its maximum length in size L ͚ = 48.62 cm with a growth coefficient (K) of 0.68 year-1. Fishing mortality (F= 0.87) is higher than natural mortality (0.63). Exploitation level of striped snakehead in Rawa Aopa waters is categorized as overfishing (E> 0.5).Keywords : Striped snakehead, isometrics, overfishing, Aopa Swamp, Southeast Sulawesi

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.  

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