scholarly journals Growth, mortality and yield of Atherina boyeri Risso, 1810 from Lesina lagoon (Adriatic Sea, Italy)

2020 ◽  
Vol 61 (2) ◽  
pp. 163-174
Author(s):  
Ermelinda Prato ◽  
Francesca Biandolino ◽  
Andrea Ruscito ◽  
Febo Lumare ◽  
Daniela Lumare ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Total Mortality ◽  
Recruitment Pattern ◽  
Growth Coefficient ◽  
Maximum Value ◽  
Lesina Lagoon ◽  
Exploitation Rate ◽  
Exploitation Status ◽  
Relationship Of ◽  
Probability Of Capture

Population structure, growth, age, mortality and exploitation status of Atherina boyeri, caught in the period from June 2013 to May 2014 in the Lesina lagoon (Apulia region, southern Adriatic) was studied. Samples were taken each month by using beach seines . The length–weight relationship of all sand smell specimens was described by the equation W=0.012*TL 3.10; (R2= 0.84). Population parameters including the asymptotic length (L∞) and growth coefficient (K) were assessed to evaluate the stock status. The recruitment pattern was modeled with a FiSAT routine. The asymptotic length (L∞) was 111.0 mm, while the growth coefficient (K) was 0.68 year−1. The growth performance index ((φ’) reached 3.92. The total mortality coefficient “Z”, the natural mortality coefficient “M” and the fishing mortality coefficient “F” were estimated as 2.24, 1.48 and 0.76 year-1, respectively. Exploitation rate for the population of A. boyeri in the Lesina lagoon estimated as 0.34 was resulted still lower than the predicted maximum value of Emax 0.59. The probability of capture indicated that L50 was of 55.57 mm, indicating that the stock of sand smelt in Lesina lagoon is not being over-fished.

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.

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 Some Aspect on the Biology of Pen Shell Atrina Pectinata (Linneaus, 1767) In Coastal Waters of Maqueda Bay, Philippines

2019 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Coastal Waters ◽  
Total Mortality ◽  
Condition Index ◽  
Recruitment Pattern ◽  
Spawning Period ◽  
Growth Coefficient ◽  
Measurement And Analysis ◽  
Pen Shell ◽  
Atrina Pectinata

A Total of 379 pen shells Atrinapectinata were collected from February 2017 to January 2018 in the coastal waters of Maqueda Bay. Measurement and analysis of length and weight were done using FiSAT software. Population parameters were assessed to evaluate the stock status which includes the asymptotic length (L∞) and growth coefficient (K) to be 34.65 cm, 0.77 year−1 respectively. Specimens of A. pectinata reached a mean length of 20.98 cm. Length-weight relationship resulted to “negative allometric” 0.0462L2.6533 R2 = 0.7823; signifying pen shells growth was faster in length than on weight. The recruitment pattern was continuous over the year with one major peak during rainy season (July). In addition, the highest catch based on collected sampling date catch was during summer, which suggest as the peak season of the species in the area. Furthermore, the average catch annually of hookah diver was 17.69208. Higher condition index was recorded from April to May, September and January, indicating the high quality of pen shell meat and is recommended as the best period to harvest pen shell whereas June to August and October to December can be concluded as the spawning period of the pen shell and the ideal period to institute close season. Further analysis revealed that the pen shell was nearly facing overexploitation with the exploitation rate (E = 0.46) mainly due to lack of a minimum limit size and also due to an increase in the harvesting effort. The estimated total mortality (Z), natural mortality (M) and fishing mortality (F); 1.36 year−1, 1.01year−1 and 0.62 year−1, respectively. Using the mentioned (Z), (M), (F) and (E), the total population resulted to 84725.7 suggesting that half of the population has been exploited due to overfishing

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 DINAMIKA POPULASI DAN STATUS PEMANFAATAN UDANG TIGER (Penaeus monodon Fabricius 1798) DI PERAIRAN TARAKAN, KALIMANTAN UTARA

2020 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Umi Chodrijah ◽  
Ria Faizah ◽  
Tirta Danu
Keyword(s):  
Growth Parameters ◽  
Penaeus Monodon ◽  
Total Mortality ◽  
Optimal Level ◽  
Survey Method ◽  
Von Bertalanffy ◽  
Population Parameters ◽  
Exploitation Rate ◽  
Tiger Prawn ◽  
Exploitation Status

Udang tiger (Penaeus monodon Fabricius 1798) di Tarakan merupakan salah satu komoditas ekspor dan sudah dimanfaatkan cukup lama serta memiliki permintaan dan nilai ekonomis yang tinggi. Penelitian dinamika populasi dan status pemanfaatan udang tiger di perairan Tarakan dan sekitarnya dilakukan untuk mengevaluasi status stok sumberdaya udang agar pengelolaannya dapat berkelanjutan. Penelitian ini dilakukan pada bulan Januari-November 2016 dengan metode survey. Status pemanfaatan diduga berdasarkan laju eksploitasi dan estimasi rasio pemijahan berbasis data panjang (LB-SPR). Hasil pengamatan menunjukkan udang tiger memiliki panjang karapas asimptotik (CL∞) sebesar 65,45 mm, laju pertumbuhan (K) sebesar 1,55 /tahun dan nilai t0 sebesar -0,20/tahun sehingga diperoleh persamaan pertumbuhan Von Bertalanffy CLt = 65,45(1 – e-1,55(t+-0,20)). Laju mortalitas total (Z) sebesar 6,56/ tahun, mortalitas alami (M) sebesar 1,95/tahun, mortalitas penangkapan (F) sebesar 4,62/tahun dan tingkat pemanfaatan (E) sebesar 0,70 /tahun. Tingkat pemanfaatan udang tiger di perairan Tarakan lebih besar dari tingkat pemanfaatan optimal sehingga disarankan untuk menurunkan upaya sebesar 40% dari upaya saat ini.Tiger prawn (Penaeus monodon Fabricius 1798) was one of the export commodity and had been exploited for longtime ago so it was necessary to study about its population parameters and exploitation status for its sustainable management. This research aimed to study about the population parameters and exploitation status of tiger prawn. The research were carried out from January to November 2016 using survey method and the enumeration programme. The growth parameters were based on the Modal Progression Analysis. Exploitation status was estimated based on length based spawning potential ratio (LB-SPR). The results showed that the asymptotic length (CL∞) was 65.45 mm, the growth rate (K) was 1.55 /year and = t0 was -0,20/year so Von Bertalanffy Growth Model was CLt = 65.45(1 - e -1.55(t+-0.20)). Total mortality (Z) was 6.56/years, natural mortality was 1.95/years and fishing mortality was 4.62/years and the highest recruitment of tiger prawns occured in May. The exploitation rate (E) was 0,70/years. The exploitation rate now is higher then the optimal level so it is recommended to reduce 40% of the current efforts.

scholarly journals Population dynamics of Mormyrus rume (Valenciennes, 1847; Osteoglossiformes; Mormyridae) Of Ikere-Gorge, Iseyin, Oyo State, Nigeria

2020 ◽  
Vol 19 (1) ◽  
pp. 51-57
Author(s):  
Stephen O. Ajagbe ◽  
Folashade. F. Ojo-fakuade
Keyword(s):  
Growth Parameters ◽  
Management Strategies ◽  
Total Mortality ◽  
Mesh Size ◽  
Fish Population ◽  
Population Parameters ◽  
Growth Coefficient ◽  
Exploitation Rate ◽  
Length Frequency Data ◽  
Mormyrus Rume

The structure of a fish population is determined by the equilibrium between growth, recruitment and total mortality. But, there is paucity of information on the growth and mortality of Mormyrus rume in Nigeria. Therefore this study is needful to determine its population parameters, with a view of evolving management strategies for its sustainable exploitation. Estimates of population parameters of Mormyrus rume were obtained from length-frequency data of 836 individuals collected monthly for a period of 24 months from January 2017 to December 2018. The estimated growth parameters were: asymptotic length (L∞) was 100.8cm; growth coefficient (K) was 0.62/year; growth performance (Ɵ) was 3.8; length at maturity (Lm) was 52.57cm; reproductive load (Lm/L∞) was 0.52 and optimum length (Lopt) was 65.10cm. Likewise, natural, fishing and total mortalities were 0.93, 1.46 and 2.39 respectively. The values of exploitation rate (0.61) and ratio of total mortality and growth coefficient (3.85) showed that Mormyrus rume is most exploited in Ikere-gorge. Therefore, appropriate fishing regulations should be enforced to regulate fishing gears and mesh size that will fish Mormyrus rume at sustainable level. Keywords: Recruitment, mortality, growth, exploitation, length

scholarly journals Population dynamics of anchovy pekto (Stolephorus waitei) in the waters of Malacca Strait, North Sumatra, Indonesia

2021 ◽  
Vol 22 (7) ◽  
Author(s):  
Miswar Budi Mulya ◽  
ARLEN HANEL JHON ◽  
ZULHAM APANDY HARAHAP
Keyword(s):  
Population Dynamics ◽  
Growth Parameters ◽  
Good Condition ◽  
Fork Length ◽  
Total Mortality ◽  
Recruitment Pattern ◽  
Water Region ◽  
Relationship Of ◽  
North Sumatra ◽  
Malacca Strait

Abstract. Mulya MB, Jhon AH, Harahap ZA. 2021. Population dynamics of anchovy pekto (Stolephorus waitei) in the waters of Malacca Strait, North Sumatra, Indonesia. Biodiversitas 22: 2693-2698. Anchovy pekto or Stolephorus waitei (Engraluidae: Clupeiformes) is one of the fish in the eastern coastal part of North Sumatra, occupying the waters of Malacca Strait. This research presents the population dynamics of S. waitei following its age, growth, mortality, and recruitment pattern based on the length-frequency data. Fork length (FL) and total weight (TW) data of S. waitei were collected at three sites from April to September 2018. A total of 1994 specimens with FL from 4.0 to 6.7 cm and TW from 0.2 to 2.3 g with the length-weight relationship of TW = 0.073FL3.0046 (R2=0.765) indicated a near isometric and positive allometric growth in the water region. The relative condition factor (Kn) ranged from 1.01 to 1.02, indicating an estimate of good condition of the fishes. The growth parameters based on von Bertalanffy was 6.56 cm (L?) with the growth coefficient (K) of 0.34 yr-1 and t0 (anchovy age at zero length ) of 0.6506. The total mortality (Z), natural mortality (F), and catch mortality (M) of S. waitei were 0.64, 1.39, and 0.75 yr-1 respectively, which suggest that the fishing activities of S. waitei are still in normal intensity. The recruitment pattern of S. waitei was stable between April and August with its peak in June by 14.21%. The fishing activities may then be limited during the spawning months (May to June) of S. waitei to maintain their population in the Strait of Malacca.

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.

scholarly journals BIOLOGY AND POPULATION DYNAMICS OF BANANA SHRIMP (Penaeus merguiensis) IN THE TARAKAN WATERS, EAST BORNEO

2013 ◽  
Vol 19 (2) ◽  
pp. 99 ◽  
Author(s):  
Duranta D. Kembaren ◽  
Ali Suman
Keyword(s):  
Population Dynamics ◽  
Mortality Rate ◽  
Total Mortality ◽  
Population Data ◽  
Fishing Effort ◽  
Growth Coefficient ◽  
Exploitation Rate ◽  
First Maturity ◽  
Dynamic Population ◽  
Penaeus Merguiensis

Study of biology and population dynamic of banana shrimp (<em>Penaeus merguiensis</em>) in Tarakan waters, East Borneo was carried out from January to November 2012. The aim of this research was to identify the biological aspects and population dynamics of banana shrimp. For estimating dynamic population, data were analysed using FiSAT II. The result showed that length at first capture (Lc) of banana shrimp by mini trawl (pukat hela) was 35 mm and the size at first maturity (Lm) was 33,86 mm in carapace length. Spawning occured all year around and reached it’s peak in March. The growth coefficient (K) of banana shrimp was 1,45/year with carapace asymptotic length (CL”) of 80 mm. Total mortality rate (Z) and natural mortality rate (M) were 4,85/year and 1,76/year. While fishing mortality rate (F) and exploitation rate (E) were 3,09/year and 0,64, respectively. The exploitation rate of banana shrimp in Tarakan waters tended to be overexploited so that it needed to be managed wisely and carefully by reducing the fishing effort and fishing season especially on spawning season. The recruitment peak of banana shrimp occured in May.

scholarly journals Population Dynamics of Five Important Commercial Fish Species in the Sundarbans Ecosystem of Bangladesh

2019 ◽  
pp. 1-13
Author(s):  
Md. Golam Mustafa ◽  
Imran Ahmed ◽  
Mohammod Ilyas
Keyword(s):  
Population Dynamics ◽  
Fish Species ◽  
Total Mortality ◽  
Assessment Tools ◽  
Natural Mortality ◽  
Lates Calcarifer ◽  
Recruitment Pattern ◽  
Exploitation Rate ◽  
Acanthopagrus Latus ◽  
The Sundarbans

Aims: To determine the population dynamics and assess the exploitation level of Mystus gulio, Acanthopagrus latus, Chelon parsia, Otolithoides pama and Lates calcarifer in the Sundarbans ecosystem of Bangladesh. Study Design: Monthly length-frequency data of five fish species were collected from the Sundarbans ecosystem. The lengths of five fish species were recorded to the nearest one cm intervals in each month. Place and Duration of Study: The study was conducted from January to December 2011 in the Sundarbans ecosystem in Bangladesh. Methodology: The FAO-ICLARM Fish Stock Assessment Tools (FiSAT II) software was used to estimate the von Bertalanffy growth parameters (L∝ and K), mortality coefficients (Z, M and F), probability of capture, recruitment pattern and Yield/Biomass-per-recruit for five commercially important fish species caught by fishers in the Sundarbans ecosystem of Bangladesh. Results: In the Sundarbans ecosystem of Bangladesh area the values of asymptotic length (L∝) for Mystus gulio, Acanthopagrus latus, Chelon parsia, Otolithoides pama and Lates calcarifer were found to be 23.0 cm, 33.6 cm, 30.0 cm, 32.5 cm and 55.0 cm respectively while the growth co-efficient (K) were 0.75, 0.85, 1.1, 0.8 and 0.5 respectively. The estimates for L∝ (23.00 – 55.0 cm) and K (0.5-1.1 year-1) obtained were consistent with those available in the literature. Relatively high K and low L∝ values, typical of short-lived tropical fishes, were obtained for Mystus gulio, Acanthopagrus latus, Chelon parsia and Otolithoides pama. The length growth performance index (ϕ’) of the Pauly and Munro’s function was in the range of 2.599 – 3.180. Natural mortality, fishing mortality and total mortality were in the range of 0.956-1.89, 0.55-1.58 and 1.52-3.3 respectively. Estimates for total mortality (Z) and natural mortality (M) imply low annual rates of survival and high turnover rates. The recruitment pattern suggested one main pulse of annual recruitment. The exploitation rate was estimated to be between 27% and 47% and the length at first capture was estimated to be approximately 19-54% of L∝. The exploitation rate obtained for five fish species are relatively lower compared to other available studies in the coastal areas of Bangladesh. The growth and exploitation rates obtained were compared with available estimates to evaluate the consistency of the results with current knowledge about the species in the region. Conclusion: The study indicated that the length-at-first-capture/L∝ seem to be a simple parameter, which could be used to make a rapid assessment of the status of the stocks. All together, the present study reveals that the population of these five studied species attains acceptable sustainability levels in the Sundarbans ecosystem and scope for a slight increase in catch efforts.

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