Life history traits of the exploited limpet Patella candei (Mollusca: Patellogastropoda) of the north-eastern Atlantic

2011 ◽  
Vol 92 (6) ◽  
pp. 1379-1387 ◽  
Author(s):  
P. Henriques ◽  
R. Sousa ◽  
A.R. Pinto ◽  
J. Delgado ◽  
G. Faria ◽  
...  
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Growth Parameters ◽  
Total Mortality ◽  
Recruitment Pattern ◽  
Length Relationship ◽  
North Eastern ◽  
Exploitation Rate

Life history traits of Patella candei were studied for the first time, including weight versus length relationship, growth, age structure, sexual maturity, recruitment pattern, mortality rates and yield and biomass-per-recruit of an exploited population in Madeira Island, north-eastern Atlantic using monthly length–frequency data from January to December 1999. The growth pattern of P. candei showed positive allometric nature of growth (b > 3, P < 0.05). The estimated growth parameters showed an asymptotic length (L∞) and growth coefficient (K) estimated at 80.81 mm and K at 0.32 year−1 with a growth performance index (φ′) calculated as 3.32 based on the collected data. This species is moderately long-lived reaching up to 9.36 years and achieving sexual maturity at 36.7 mm of shell length. The recruitment pattern was continuous, displaying a major peak event per year, occurring in January (25.12%). The estimated total mortality rate (Z) was 1.79 year−1 while natural mortality rate (M) was 0.55 year−1 and fishing mortality rate (F) was 1.24 year−1. The probability of capture shows that the length at first capture (Lc) was 42.7 mm, the exploitation rate (E) 0.693 and the maximum allowable limit of exploitation (Emax) was 0.779 for the highest yield. The exploitation rate was less than the predicted Emax values, showing that the stock of P. candei was found to be under-exploited in the investigated area; however, its slow growth and long life make it extremely vulnerable to over-exploitation.

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.  

Estimating some population parameters and stock assessment of Dark Sleeper Odontobutis potamophila in the Gaosha River, Wuyuan County, Jiangxi Province, China

2017 ◽  
Author(s):  
Wu Bin Wang Haihua ◽  
Fu Huiyun Zhang Yanping
Keyword(s):  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Landing Site ◽  
Jiangxi Province ◽  
Recruitment Pattern ◽  
Growth Coefficient ◽  
West Part ◽  
Exploitation Rate ◽  
Odontobutis Potamophila

A study was conducted to investigate the growth parameters, mortality and recruitment pattern of Odontobutis potamophila collected in the Gaosha river fish landing site, west part of Wuyuan County (Latitude: 29° 14' 29" N, Longitude: 117° 45' 49" E). O.potamophila were collected from November, 2013 to October, 2014. Growth parameters, asymptotic length (L) = 192mm and growth coefficient (k) = 0.22 year-1. Growth performance index(Ø’) =3.91, total mortality (Z) = 0.72 year-1, natural mortality (M) = 0.32 year-1, fishing mortality (F) = 0.40 year-1 and exploitation rate (E) = 0.55year-1.The estimated exploitation rate (E) has slightly exceeded the optimum value of E indicating this species was sustainable exploitation in the study area. The exploitation ratios were computed as Emax= 0.61, E10= 0.52, E50= 0.34. The length at first capture at 50%, (Lc) was 77 mm. The recruitment pattern of the species was found continuous all-round the year with one peak. The observation of the annual recruitment of O.potamophila found to occur from May to July. Steady biomass also increased with length class until 121-125 mm, and the total steady state biomass was found to be 2240 kg.

scholarly journals Population dynamics of Sardinella aurita (Val., 1847) within Ghana’s coastal waters

2017 ◽  
Vol 4 (3) ◽  
pp. 237-248
Author(s):  
Samuel KK Amponsah ◽  
Patrick K Ofori Danson ◽  
Francis KE Nunoo ◽  
Godfred A Ameyaw
Keyword(s):  
Mortality Rate ◽  
Coastal Waters ◽  
Total Mortality ◽  
Mesh Size ◽  
Reference Points ◽  
Recruitment Pattern ◽  
Commercial Fish ◽  
Management Interventions ◽  
Exploitation Rate ◽  
Sardinella Aurita

Following the declining stocks of Sardinella aurita within the coastal waters of Ghana, this study aimed at examining some population parameters of Sardinella aurita as a guide for managing this important stock sustainably. Length-frequency data of 717 samples were obtained from June, 2014 to January 2015 and measured for total length with the resultant data analyzed using FiSAT II. The asymptotic length (L∞) and growth rate (K) were 21.53 cm SL and 0.25yr-1 respectively. The theoretical age at birth (t0), longevity (tmax) and growth performance index (ϕ) were -0.74yr-1, 12 years and 1.849 respectively. Total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 3.17, 0.76 and 2.41yr-1 respectively. The ages at first recruitment and first capture signaled future collapse of the stock, in the absence of proper management interventions. VPA outcome showed that mid- lengths of 11 cm and 12 cm SL experienced the highest harvesting rate with MSY estimated at 7733 tons. The recruitment pattern was continuous with two major recruitment pulses. Exploitation rate (Ecurr=0.76) was higher than the maximum exploitation rate (Emax=0.56), indicating unsustainable exploitation. Further, the fishing regime fell within the overfished stage based on the Quadrant Rule. For sustainable exploitation of this commercial fish species, implementation of relevant biological reference points through reduction in fishing efforts, creation of marine protected areas and mesh size regulation are urgently advocated.Res. Agric. Livest. Fish.4(3): 237-248, December 2017

scholarly journals Population Parameters of Two Commercially Important Species belonging to the Family Sciaenidae Encountered in the Coast of Ghana

2020 ◽  
pp. 21-29
Author(s):  
Samuel K. K. Amponsah ◽  
Selasi Yao Avornyo ◽  
Kofi Ferni Anyan
Keyword(s):  
Mortality Rate ◽  
Fish Species ◽  
Coastal Waters ◽  
Total Mortality ◽  
Population Parameters ◽  
Recruitment Pattern ◽  
Important Species ◽  
The Family ◽  
Exploitation Rate ◽  
Commercially Important

Population parameters for two commercially important fishes of Sciaenidae from the coastal waters of Ghana were assessed using length-frequency data obtained from August 2017 to June 2019. Samples of the assessed fish species were obtained through experimental fish trawl along the coast of Greater Accra, Ghana. Trawling was performed every quarter for an average of one hour at an average speed of 3.0 km/hr. In all, a total of 399 samples were measured and the obtained data were analyzed with FiSAT II. The assessed fish species included Pteroscion peli (165 samples) and Pseudotolithus senegalensis (234 samples). The asymptotic length (L∞) was 19.4 cm and 41.5 cm forPteroscion peli and Pseudotolithus senegalensis. Pteroscion peli and Pseudotolithus senegalensis recorded growth rate (K) of 0.48 and 0.50 per year respectively. Both assessed fish species exhibited continuous recruitment pattern with minor and major recruitment peaks. The total mortality rate (Z) was 1.86 and 1.63 per year for Pteroscion peli and Pseudotolithus senegalensis. The fishing mortality rate (F) was estimated at 0.66 and 0.63 per year for Pteroscion peli and Pseudotolithus senegalensis. The natural mortality rate (M) estimated for Pteroscion peli and Pseudotolithus senegalensis was 1.20 and 1.00 per year respectively. The exploitation rate (E) of Pseudotolithus senegalensis (0.39) and Pteroscion peli (0.36) respectively was far below the maximum exploitation rate (Emax), indicating under-exploitation of its fishery in the coastal waters of Ghana, hence the need to enhance the exploitation of these species.

Estimation of Population Parameters and Stock Assessment of Mastacembelus armatus in the Taojiang River, Xinfeng County, Jiangxi Province, China

2019 ◽  
Author(s):  
Wu Bin ◽  
Wang Haihua ◽  
Ma Benhe ◽  
Xu Xiandong ◽  
Zeng Qingxiang
Keyword(s):  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Landing Site ◽  
Jiangxi Province ◽  
Recruitment Pattern ◽  
Growth Coefficient ◽  
Exploitation Rate ◽  
Mastacembelus Armatus ◽  
River Fish

A study was conducted to investigate the growth parameters, mortality and recruitment pattern of Mastacembelus armatus collected in the Taojiang River fish landing site, Xinfeng County. M. armatus were collected from March, 2018 to February, 2019. Growth parameters, asymptotic length (L¥) = 58.8cm and growth coefficient (k) = 0.13 year-1. Growth performance index(Ø2 ) =2.65, total mortality (Z) = 0.75 year-1, natural mortality (M) = 0.32 year-1, fishing mortality (F) = 0.43 year-1 and exploitation rate (E) = 0.57year-1.The estimated exploitation rate (E) has slightly exceeded the optimum value of E indicating this species was over exploited mainly due to fishing in the study area. The exploitation ratios were computed as Emax= 0.59, E10= 0.45, E50= 0.31. The length at first capture at 50%, (Lc) was 19.51 cm. The Steady biomass also increased with length class until 36.0-36.9 cm and the total steady state biomass was found to be 19.12 tons.

scholarly journals Growth, Mortality, and Exploitation Rate of Penaeus merguensis in the North Coast of Central Java, Indonesia

2019 ◽  
Vol 23 (4) ◽  
pp. 207
Author(s):  
Suradi Wijaya Saputra ◽  
Anhar Solichin ◽  
Wiwiet Teguh Taufani
Keyword(s):  
Mortality Rate ◽  
Population Biology ◽  
Carapace Length ◽  
Growth Parameters ◽  
Total Mortality ◽  
Survey Method ◽  
North Coast ◽  
Optimum Level ◽  
Central Java ◽  
Exploitation Rate

One of the most-caught shrimp in north coast of Central Java is Penaeus merguiensis. However, little is known on the population biology of the organisms. This study was aimed to investigate length-weight relationship, growth, length at first capture (Lc50), mortality rate, and exploitation rate of P. merguiensis in Western part of Central Java’s northern coastal waters. The study was conducted from May 2016 to July 2017 using survey method. Samples were taken for 15 times (month) from 9 coastal fishing ports. The result shows that the relationship of the carapace length and weight is negative allometry. The growth parameters of CL∞ and K were 52.5mm and 1.3 y-1 (male) and 57.25mm and 1.2 y-1 (female). Total mortality rate (Z), natural mortality rate (M), and fishing mortality rate (F) were 4.51 y-1, 1.86 y-1 and 2.65 y-1 (male), and 5.36 y-1, 1.72 y-1, and 3.64 y-1 (female), respectively. The exploitation rate (E) of male banana shrimp was 0.59, and for female shrimp was 0.68. The result shows that the exploitation level has exceeded the optimum level (E>0.5). Recruitment of P. merguiensis may occur the whole year, but it peaks were in March and August (male), April and August (female). Carapace length of first captured (CLc50) was 20.63mm (male) and 18.28mm (female). It means that the sized of captured P. merguiensis is less than the size of first mature (CLm50) or growth overfishing and as a result, disrupting the availability of adult shrimp. The condition occurs due to the size of cod-end mesh measured 0.75inc.

scholarly journals PENDEKATAN POLA PEREMAJAAN DAN LAJU EKSPLOITASI IKAN LOUHAN UNTUK PENGENDALIAN IKAN ASING INVASIF DI DANAU MATANO, SULAWESI SELATAN

2018 ◽  
Vol 23 (4) ◽  
pp. 227
Author(s):  
Dimas Angga Hedianto ◽  
Hendra Satria
Keyword(s):  
Mortality Rate ◽  
Alien Species ◽  
Invasive Alien Species ◽  
Total Mortality ◽  
Growth Equation ◽  
Recruitment Pattern ◽  
Lake Matano ◽  
South Sulawesi ◽  
Exploitation Rate ◽  
Annual Total

Ikan louhan tergolong jenis ikan hibrid (sehingga tidak dapat ditentukan nama ilmiahnya) dari famili Cichlidae yang terindikasi sebagai ikan asing invasif di Danau Matano. Keberadaan ikan tersebut di Danau Matano perlu dikaji dan dikendalikan untuk menjaga kelestarian keanekaragaman hayati jenis ikan endemik. Penelitian ini bertujuan untuk menganalisis pola peremajaan dan laju eksploitasi ikan louhan sebagai pendekatan dalam pengendalian ikan asing invasif di Danau Matano, Sulawesi Selatan. Analisis data dilakukan terhadap 2.931 ekor ikan louhan yang ditangkap menggunakan jaring insang percobaan berbagai ukuran mata jaring dilengkapi data enumerator secara bulanan pada bulan Februari hingga November 2016 dengan bantuan perangkat lunak FiSAT II. Hasil analisis menunjukkan bahwa pola pertumbuhan ikan louhan di Danau Matano bersifat alometrik positif. Pertumbuhan mengikuti persamaan Lt=23,67[1-e0,41(t+0,4281)]. Umur maksimum (tmax) mencapai 7,32 tahun dengan performa pertumbuhan (Ø’) sebesar 2,36. Laju mortalitas total (Z) tahunan didapatkan sebesar 1,46 tahun-1. Laju mortalitas penangkapan tahunan (F = 0,38 tahun-1) lebih rendah daripada laju mortalitas alami tahunan (M = 1,08 tahun-1). Laju eksploitasi (E) ikan louhan di Danau Matano hanya sebesar 0,26 tahun-1 dimana menunjukkan bahwa upaya pemanfaatannya masih sangat rendah. Pola peremajaan terjadi dua kali dalam setahun, yaitu pada Mei (16,19%) dan Oktober (6,05%). Upaya pengendalian ikan louhan sebagai ikan invasif di Danau Matano perlu dilakukan pada saat puncak peremajaan tertinggi secara berkesinambungan disertai peningkatan laju eksploitasi e” 48% dari upaya yang ada, terutama pada April-Mei dan September-Oktober di daerah litoral perairan danau.Flowerhorn cichlid is classified as hybrid species (so that the scientific name can’t be determined) from Cichlidae which indicated as invasive alien fish in Lake Matano. The existence of flowerhorn in Lake Matano need to be assessed and controlled to preserve the biodiversity of endemic fish species. This research aims to assess recruitment pattern and utlization status of flowerhorn cichlid for controlling of invasive alien species at Lake Matano, South Sulawesi. Data analysis was carried out on 2,931 flowerhorn Cichlid caught using experimental gillnets of various mesh sizes included enumerators data which recorded monthly from February to November 2016 using FiSAT II software. The analysis resulted the growth pattern of flowerhorn cichlid in Matano louhan Lake was positive allometric. The growth equation of flowerhorn cichlid was Lt=23.67[1-e0,4(t+0.4281)]. Longevity (tmax) attained 7.32 years with growth performance (Ø’) was 2.36. The annual total mortality rate (Z) obtained 1.46 years-1. The annual fishing mortality rate (F = 0.38 years-1) is lower than the annual natural mortality rate (M = 1.08 years-1). Exploitation rate (E) of flowerhorn cichlid in Lake Matano only 0.26 years-1, which was indicated under exploitation. Recruitment pattern occurs twice a year, in May (16.19%) and October (6.05%). The eradication efforts to control population of flowerhorn cichlid as invasive alien species in Lake Matano needs to be done at the peak of recruitment and also increased exploitation rate about e” 48% of existing efforts, especially on April-May and September-October in the littoral area of Lake Matano.

Life History Traits of Hoplostethus Mediterraneus (Pisces: Beryciformes) From the North-Western Ionian Sea (Mediterranean Sea)

1998 ◽  
Vol 78 (1) ◽  
pp. 321-339 ◽  
Author(s):  
G. D'onghia ◽  
A. Tursi ◽  
C.A. Marano ◽  
M. Basanisi
Keyword(s):  
Life History ◽  
Mortality Rate ◽  
Life History Traits ◽  
Growth Parameters ◽  
Growth Patterns ◽  
Natural Mortality ◽  
Distribution Analysis ◽  
Ionian Sea ◽  
The North ◽  
North Western

The fish Hoplostethus mediterraneus is a bycatch of the deep-water trawling in the north-western Ionian Sea. Data on its life history traits were collected during twelve trawl surveys carried out at two month intervals, between August 1993 and July 1995.A vertical distribution according to size was observed for this species. The year's young were recruited mainly during the spring-summer period. Sex-ratio changed by size with females larger than males. Mature specimens were found mainly between May and November with a reproductive peak during late summer.Seasonal growth was detected in the otoliths; the maximum ages of 11 and 10 y were observed in females and males respectively. Von Bertalanffy growth parameters for the whole population were: L3C=287–08 mm, k=0–127 y, to=-2–131. No significant differences were detected between the growth patterns of the sexes. Overall growth perfomance depicted through size-distribution analysis was not significantly different from that obtained by otolith reading.Estimates of natural mortality rate for the whole population ranged from 0–14 to 0–20. Population structure, growth pattern, age at first maturity and low natural mortality rate indicate a life history mainly constituted by k-strategy characters and regulated by density-dependent mechanisms.

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 Growth, Mortality and Exploitation Rates of African Moonfish (Selene dorsalis, Gill 1863) Encountered in the Coast of Ghana (West Africa)

2021 ◽  
Vol 2 (2) ◽  
pp. 6-10
Author(s):  
Samuel K. K. Amponsah ◽  
Berchie Asiedu ◽  
Selasi Yao Avornyo ◽  
Seyramsarah Blossom Setufe ◽  
Pierre Failler
Keyword(s):  
Mortality Rate ◽  
West Africa ◽  
Growth Parameters ◽  
Total Mortality ◽  
Mesh Size ◽  
Optimum Level ◽  
Management Measures ◽  
Simulating Annealing ◽  
Exploitation Rate ◽  
Length Frequency Data

Growth, mortality and exploitation rate of Selene dorsalis (Gill, 1863) from the continental shelf of Ghana (West Africa) were examined between July 2018 and June 2019. The study provided results on fishery dynamics parameters needed to estimate the stock status and characteristics of S. dorsalis in the coast of Ghana. Monthly length-frequency data were collected from 629 samples and analysed using fisheries models fitted in TropFishR package in R software. The von Bertalanffy growth parameters were utilised to analyse the population dynamics of the species using ELEFAN Simulating Annealing. Based on the estimates, the asymptotic total length (L∞) was 22.2 cm, the coefficient of growth (K) was 0.76 year-1, and the calculated growth performance index (phi) was 2.58 with Rn value of 0.55. The total mortality rate (Z) was 3.32 year-1 with a natural mortality rate (M) of 1.21 year-1 and fishing mortality rate (F) of 2.11 year-1. The exploitation rate (E) estimated for the species was above the optimum level of 0.5, which indicates that S. dorsalis is overexploited in the coast of Ghana. It can be concluded that the exploitation rate of S. dorsalis has exceeded the optimum limit, hence the need for enforcement and improvement of fisheries management measures such as mesh size regulations, capping of canoes, closed fishing seasons and compliance with fisheries policies.

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