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 Dynamics and Management of Invasive Blue Tilapia (Oreochromis aureus) in Garmat Ali River, Basrah, Iraq

2020 ◽  
pp. 44-54
Author(s):  
Abdul-Razak M. Mohamed ◽  
Ayat N. Salman
Keyword(s):  
Population Dynamics ◽  
Growth Parameters ◽  
Relative Yield ◽  
Total Mortality ◽  
Reference Points ◽  
Recruitment Pattern ◽  
Oreochromis Aureus ◽  
Biological Target ◽  
Blue Tilapia ◽  
Yield Per Recruit

The blue tilapia, Oreochromis aureus is an invasive species that has successfully established itself in most of the Iraqi waters. However, there is little information on the population dynamics of the species in these waters. Hence, the growth parameters, mortality rates, probability of capture, recruitment pattern and yield per recruit of blue tilapia in Garmat Ali River, Iraq was assessed using FiSAT II software. A total of 1664 blue tilapia fish were collected by different fishing gears from October 2019 to September 2020 for recording the relevant data. The length-weight relationship obtained was W=0.0147*L3.0748 for fish ranging from 7.5 to 26.3 cm total length suggesting that the species shows positive allometric growth. The asymptotic length (L∞), growth constant (K), theoretical age at zero-length (t0), growth performance index (Ø') and longevity (tmax) were 29.9 cm, 0.205, -1.293, 2.345 and 10.7 years, respectively. The total mortality (Z), natural (M), fishing (F) and exploitation (E) were 1.09, 0.61, 0.48 and 0.43, respectively. Length at first capture (L50) was found to be 13.92 cm. The main recruitment pulse was from March to July with a peak in April, which account for 18.4% of the total recruitment in the year. The relative yield per recruit analysis revealed that the present exploitation rate (Epresent) for blue tilapia was below than the biological target reference points (E0.1 and Emax), which denotes that this stock was not over-exploited. For management purposes, higher yields can be achieved by reducing the mesh sizes of the nets during fishing.

scholarly journals Population Dynamics and Stock Assessment of Gudusia chapra (Hamilton-Buchanan) in the Rajdhala Reservoir, Netrakona, Bangladesh

2007 ◽  
Vol 19 (3) ◽  
Author(s):  
M. A. RAHMAN ◽  
M. M. HAQUE
Keyword(s):  
Population Dynamics ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Maximum Sustainable Yield ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Recruitment Pattern ◽  
Pattern Maximum

Population dynamics and stock assessment of chapila (Gudusia chapra, Hamilton-Buchanan) in the Rajdhala reservoir, Netrakona, Bangladesh was studied from January 2003 to December 2004 using length-frequency based analysis of FiSAT software to evaluate the growth parameters, mortality rates, exploitation rates, recruitment pattern, maximum sustainable yield (MSY) and the corresponding fishing mortality at this level. The annual rates of natural mortality, fishing mortality and total mortality were 1.34, 1.37 and 2.71 yr-1 in 2003 and 1.37, 1.58 and 2.95 yr-1 in 2004 respectively. The study revealed that the fishes were recruited in the fishery twice a year and the fishes were harvested at a higher level than the optimum fishing pressure. Twenty four percent of the present exploitation pressure on chapila is suggested to be reduced to get the MSY of this fish from the reservoir.

Population dynamics and stock assessment of Hilsa shad, Tenualosa ilisha (Hamilton, 1822) along the coast of Bangladesh

2021 ◽  
Vol 48 (2) ◽  
pp. 231-241
Author(s):  
Md Khairul Islam ◽  
Md Humayun ◽  
Manmatha Nath Sarker ◽  
Md Sharifuddin ◽  
M Niamul Naser
Keyword(s):  
Growth Parameters ◽  
Stock Assessment ◽  
Population Analysis ◽  
Total Mortality ◽  
Maximum Sustainable Yield ◽  
Fishing Mortality ◽  
Recruitment Pattern ◽  
Weight Relationship ◽  
Tenualosa Ilisha ◽  
Highly Correlated

Stock Assessment of Tenualosa ilisha (Hamilton, 1822) were estimated using FiSAT-II software with length-frequency data collected from different landing centers. The Southeast Coast of Bay Of Bengal, Cox's Bazar. The Von Bertalanffy growth parameters Land K for the species were asymptotic length (L∞) was 51.41 cm, growth rate (K) was 0.75 year-1 and t0 = -0.2 year respectively. The estimated value of total mortality (Z) based on length converted catch curve using these growth parameters was 2.35 year-1.Natural mortality (M) based on growth parameters and mean environmental temperature (T = 27° C) was 1.00 year-1 and fishing mortality (F) was 1.35 year-1. Optimum length of hilsa at first capture (Lc=L50) was 28.36 cm TL. Growth performance indices (ϕ') was 3.30. The estimated value of the exploitation rate (E) using the length-converted catch curve was 0.57. The recruitment pattern of this species was continuous and two peaks per year. The present investigation clearly showed the over fishing (E > 0.50) condition for T. ilisha in Bangladesh. The estimated length-weight relationship for the combined sex was found to be W = 0.0109 L3. Virtual population analysis (VPA) showed that the maximum fishing mortality occurring in the length between 30 to 35 cm with a maximum value in the length of 32 cm that repeatedly indicate high fishing mortality in the T. ilisha. The generalized length-weight relationship was fitted with the pooled data of all monthly samples were BW = 0.029 TL2.718 (R2= 0.833) respectively. The results revealed that all length-weight relationships were highly correlated (r > 0.993). Maximum sustainable yield (MSY) was estimated as 435,554 t. Bangladesh J. Zool. 48(2): 231-241, 2020

Population dynamics of the bivalve Laternula elliptica from Potter Cove, King George Island, South Shetland Islands

1998 ◽  
Vol 10 (2) ◽  
pp. 153-160 ◽  
Author(s):  
H.-Jörg Urban ◽  
Guillermo Mercuri
Keyword(s):  
Population Dynamics ◽  
Growth Parameters ◽  
Total Mortality ◽  
Growth Function ◽  
South Shetland Islands ◽  
King George Island ◽  
Potter Cove ◽  
Cycle Growth ◽  
Laternula Elliptica ◽  
Complete Study

Body size, geographical distribution and biomass make Laternula elliptica one of the most important bivalve species of the Antarctic. A complete study on the population dynamics (reproduction cycle, growth, mortality and productivity) of this species from King George Island gave growth parameters for the von-Bertalanffy-growth-function of: L∞ = 112.2 mm, K = 0.160 yr 1, t0 = 0.000 yr. Total mortality was estimated as Z = 0.392 yr−1. Somatic production and mean biomass of two distinct sub-populations were 8.7 and 67.3 g AFDW m−2 yr−1 at Beach & Glacier and 20.0 and 88.6 g AFDW m−2 yr−1 at Punta Elefante. The following P / B values were calculated; Beach & Glacier = 0.129, Punta Elefante = 0.226. It is suggested that these differences are linked to mortality caused by icebergs which is expected to be higher at the shallower Punta Elefante site.

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.

Demography of a large exploited grouper, Plectropomus laevis: Implications for fisheries management

2010 ◽  
Vol 61 (2) ◽  
pp. 184 ◽  
Author(s):  
Michelle R. Heupel ◽  
Ashley J. Williams ◽  
David J. Welch ◽  
Campbell R. Davies ◽  
Samantha Adams ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Fork Length ◽  
Total Mortality ◽  
Coral Trout ◽  
Management Measures ◽  
Abundance Estimates ◽  
Species Specific ◽  
First Maturity ◽  
Sample Maximum

Species in the coral trout complex Plectropomus spp. are some of the most desired and exploited in the Indo-Pacific, although data are limited for most species. Demographic parameters of blue-spot coral trout, Plectropomus laevis, were estimated on the basis of specimens collected from five regions of the Great Barrier Reef and Torres Strait, Australia, between 1995 and 2005 to define demography and population status over a broad range. In total, 1249 individuals were collected to estimate growth, mortality and reproductive parameters. Growth parameters based on the von Bertalanffy model were K = 0.096 year–1, L∞ = 1159 mm fork length (FL) and the best-fit model suggested non-asymptotic growth over the size and age ranges represented in the sample. Maximum age was 16 years, total mortality was estimated at 0.39 (±0.031), and estimated size and age at first maturity were 299 mm FL (range: 299–872) and at 1 year (range: 1–6.5), respectively, with the size range over which sex change occurred at 460–872 mm FL. Population parameters and available relative abundance estimates indicated that long-term sustainable harvest rates of P. laevis will be lower than those for P. leopardus and species-specific size-based management measures are necessary to ensure the species is not overfished.

scholarly journals Population dynamics of Puntius sophore (Hamilton, 1822) of river Sutlej in Punjab (India)

2021 ◽  
Vol 42 (6) ◽  
pp. 1505-1511
Author(s):  
J. Kumar ◽  
◽  
S.N. Datta ◽  
G. Tewari ◽  
S.S. Hassan ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Extreme Values ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Maximum Sustainable Yield ◽  
Recruitment Pattern ◽  
Fish Market ◽  
Baseline Information ◽  
River Sutlej ◽  
Puntius Sophore

Aim: The aim of the present paper was to describe first and comprehensive picture on length-weight relationship and population dynamics of riverine Puntius sophore. The findings of the investigation will be an imperative part of the ecological database from river Sutlej. Methodology: The length-frequency data of 579 specimens of P. sophore captured from different stretches of river Sutlej were collected fortnightly from Tajpur fish market and Haibowal fish market (Devnagar) during April 2019 to March 2020. All the population parameters were analyzed using FiSAT II analytical package developed by FAO. Results: The estimated length-weight relationships (LWRs) of combined male and female was derived as W=0.1471 L3.0605 (r=0.98). The growth parameters were L∞=123.5 mm, K=1.18 yr-1, to= -0.7672 yr-1, Rn=0.215 and ø'=4.241. The estimated natural mortality coefficient (1.25 per yr) was greater than fishing mortality (1.03 yr-1).The present level of exploitation (E=0.45, U=0.40) of P. sophore stock indicated that stocks were under-exploited. Prediction of maximum length from extreme values at 95% confidence interval was calculated as 112.48-138.24 mm. The recruitment pattern of P. sophore showed peaks during May and June. Interpretation: The P. sophore stock was under-exploited. The fishing intensity may be standardized to obtain optimum yield per recruit and thereby ideal maximum sustainable yield. This baseline information will help in further studies on the stock assessment and formulating strategies for rational exploitation of the species.

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.

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.

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.

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