scholarly journals Population structure of Indian scad fish (Decapterus russelli) that was landed at the Nusantara Fishing Port of Ternate, North Maluku, Indonesia

2021 ◽  
Vol 890 (1) ◽  
pp. 012062
Author(s):  
A Ahmad ◽  
A N Susanto ◽  
Y J Hamisi

Abstract Indian scad fish (Decapterus russelli) is a small pelagic fish species commonly caught in Indonesian seas. Excessive fishing efforts can cause population degradation, so it is necessary to understand its population structure. The purpose of this study was to analyze the population structure parameters of Indian scad fish, including growth parameters, cohort, and mortality. Sampling was done by Stratified Random Sampling method. Data analysis used the FISAT II application. Study results showed that there were 4 cohorts. The growth parameters of Indian scad fish obtained asymptote length (L∞) of 296.15 mm, coefficient of growth rate (K) of 0.60 per year, and initial age (t0) of -0.66 years. Value of coefficient of growth rate (K) indicated that growth of scad was relatively slow. The total mortality value (Z) was 0.51 per year, natural mortality (M) was 0.0034 per year, and fishing mortality (F) was 0.51 per year. So that the highest Indian scad fish mortality was caused by fishing mortality. The exploitation rate (E) was 1 per year, indicating that the Indian scad fish resources have been overexploited.

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Akombo, Pauline Mbakaan ◽  
Atile, John Iornyiman ◽  
Shima, Judith Nguvan

The growth parameters and mortalities of five species of Synodontis in the lower river Benue at Makurdi, Benue State were studied from January,2016 to December, 2018. The asymptotic length (L∞) calculated for the five species ranged from 18.80cm in S.clarias females to 37.04cm in S.membranaceus females. The t0 values were all negative in the combined sexes of S.clarias, S.omias, S.gambiensis and S.membranaceus. In both combined sexes of S.membranaceus and S.schall, the t0 values were positive. The growth rate (K) was low in S.clarias and S.omias (0.301- 0.497, 0.171 - 0.310) respectively and higher in S.membranaceus (0.310 - 0.640), S.schall females (0.430 - 0.580); S.schall males (0.573),S.gambiensis (0.500 - 0.571). Growth performance index (Ø’) was 2.212 in S.gambiensis and 2.946 in S.schall combined. Natural Mortality (M) ranged from 0.5422 in S.omias females to 1.3340 in S.membranaceus males. Fishing Mortality (F) was 0.8214 in S.omias combined and 3.0934 in S.membranaceus females. Total mortality (Z) ranged from 1.52 in S.omias combined to 4.078 in S.membranaceus combined. Mean Exploitation (E) ratios was 0.61 in S.clarias, 0.64 in S.omias, 0.53 in S.gambiences, 0.70 in S.membranaceus, and 0.66 in S.schall. The rate at which these species survived in the River was low (from 0.147, in S.omias combined, to 1.482 in S.membranaceus combined).


1990 ◽  
Vol 41 (3) ◽  
pp. 399 ◽  
Author(s):  
MCL Dredge

Movement, growth and natural mortality rate of the red spot king prawn, Penaeus longistylus, occurring in waters of the Great Barrier Reef off Townsville, Queensland, were investigated in a series of tagging experiments. Adult P. longistylus did not migrate after leaving nursery areas. Their growth rate was slower than that of the conspecific species P. plebejus, and significant inter-annual variation in growth parameters was observed. The natural mortality rate, assessed by sequential tagging experiments that eliminated the possibility of confounding with the rate of fishing mortality, was estimated to be 0.072 (week-1).


2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah

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.  


2021 ◽  
Vol 48 (2) ◽  
pp. 231-241
Author(s):  
Md Khairul Islam ◽  
Md Humayun ◽  
Manmatha Nath Sarker ◽  
Md Sharifuddin ◽  
M Niamul Naser

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


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Syarifah Nurdawati ◽  
Zulkarnaen Fahmi ◽  
Freddy Supriyadi

Anabas testudineus Bloch, 1792 is economically important fish species found in Lubuk Lampam floodplains of Musi River. Fishing activities that take place throughout the year can affect reproduction patterns and recruitment (new additions) of fish. This study aims to evaluate several parameters of betok fish populations that can be used as input for fish resource management policies in floodplains of Musi river. A total of 3271 samples of betok fish caught by fishermen from March to November 2011 were collected to obtain data on fish length and weight. Growth parameters (L∞, K, Z dan M) were calculated using FiSAT II based on the length frequency distribution of fish. The values of L∞ and K were obtained at 204.75 mm and 0.24 / year respectively while the maximum age of fish was estimated to be 4.36 years. The total mortality (Z) and natural mortality (M) of betok fish is 0.99 / year and 0.42 / year, Fishing mortality (0.56/year). The exploitation rate (0.57) was slightly lower than the predicted value (Emax= 0.69) indicating that Anabas  testudineus was near fully exploited in the Lubuk Lampam floodplain ecosystem.  


2020 ◽  
Vol 48 (1) ◽  
pp. 81-91
Author(s):  
Khadim Hussain Memon ◽  
Rashida Bhanbhro ◽  
Qun Liu ◽  
Tahira Jabeen Ursani ◽  
Abdul Manan Shaikh ◽  
...  

Present work was done from Indus River, Sukkur, Sindh, Pakistan to evaluate the present stock of Cirrhinus reba Suhni (Reba carp) for first time. Since the assessment of stocks deliver the important knowledge of stocks of commercially important fish species to the fisheries managers to make better strategic plans for sustainable exploitation. Data based on length-frequency was obtained from October 2015 to March 2016, a total of 463 pairs of length-weight were measured. Minimum length was measured to 13cm, maximum length was 29cm and the average length of 17cm was measured with minimum weight of 15g, maximum weight of224g and67g was the average weight. Obtained results of length-weight relationship were R2 = 0.817, a = 0.037 and b = 2.557. Growth parameters were computed as L∞= 29.40 cm and= 0.240 year-1using ELEFAN method in FISAT computer package. Growth performance index (∅′) was calculated as ∅′ = 2.317 year-1 Total mortality Z, natural mortality M and fishing mortality F was estimated as= 0.630 year-1, M= 0.617 year-1 and F=0.012 year-1 respectively. Using (E = F/Z) the exploitation ratio was obtained as E=0.019 year-1 Current fishing mortality rate of 0.012 was smaller than the target biological reference points (Fopt) of M (0.617). While MSY was recorded as; 8.144 tonsyear-1 which showed the higher results than 0.031 tons year-1ofcurrent catch. This study concluded that the C. reba confronting poor health though the stocks found not to be overexploited in the region. Bangladesh J. Zool. 48(1): 81-91, 2020


2021 ◽  
Vol 56 (1) ◽  
pp. 79-86
Author(s):  
S.O. Ajagbe ◽  
D.O. Odulate ◽  
R.O. Ajagbe ◽  
O.S. Ariwoola ◽  
F.I. Abdulazeez ◽  
...  

The growth and mortality parameters of Chrysichthys nigrodigitatus were estimated to assess the sustainability of its exploitation in Ikere-gorge, Oyo State, Nigeria. A total of 1210 of Chrys­ichthys nigrodigitatus were sampled from fishermen catches between January, 2017 and Decem­ber, 2018. C. nigrodigitatus were exploited with gillnet, cast net and traps (Malian trap net and bamboo). Total lengths were measured with fish measuring board. The FAO-ICLARM Stock Assessment Tool (FiSAT II) software was used to analyze length-frequency data of the fish. The estimated growth parameters are: asymptotic length is 60.9 cm, growth coefficient is 0.96, optimum length is 38.51 cm; length at maturity is 33.44 cm while length-at-first-capture is 12.62 cm. The estimated mortality parameters are: total mortality is 3.29 per year, natural mortality is 1.43 per year and fishing mortality is 1.86. It was observed that C. nigrodigitatus of Ikere-gorge were more vulnerable to exploitation at sizes less than their length at maturity. Likewise, the ex­ploitation rate (E = 0.57 yr-1) is greater than sustainable exploitation rate (Emax = 0.46 yr-1). This shows that exploitation of C. nigrodigitatus in Ikere-gorge is not sustainable. Therefore, there is need to reduce fishing pressure on C. nigrodigitatus to ensure its sustainability in Ikere-gorge.


2021 ◽  
Vol 51 (2) ◽  
pp. 159-166
Author(s):  
Dawood Almamari ◽  
Said Rabia ◽  
Joo Myun Park ◽  
Laith A. Jawad

The blueline snapper, Lutjanus coeruleolineatus (Rüppell, 1838), is a significant commercial fish species harvested from the traditional fishery in the Sultanate of Oman. Deficient data on this species, however, make the management strategies challenging, especially in fisheries ecology. A total of 978 specimens were obtained from Dhofar Governorate off the coast of the Arabian Sea during the period between February 2015 and March 2016. In total, 296 sectioned otoliths were analyzed and growth was estimated from non-seasonal growth by using von Bertalanffy method. The parameters of von Bertalanffy growth function, total mortality (Z), natural mortality (M), fishing mortality (F), and exploitation rate (E) were determined and compared with those for Lutjanidae fishes elsewhere. The age structure of male fishes was between 1 and 14 years for males while the age of females ranged from 1 to 18 years. Growth rate (K) was 0.21 y–1 and 0.16 y–1 for males and females, respectively. The hypothetical length of female (L∞ = 46 cm) was relatively higher than that of male (L∞ = 42 cm). The natural mortality (M) was 0.296, total mortality (Z) was 0.372, fishing mortality was 0.076, and exploitation rate (E) was estimated as 0.2. The presently reported study is conducted to examine this fish in relation to growth parameters by analyzing otolith structure. The results of the presently reported study will contribute towards planning the regional fishery management policies in Oman.


2020 ◽  
Vol 8 (6) ◽  
Author(s):  
Ayat N. Salman ◽  
Abdul-Razak M Mohamed

The study was conducted to estimate the growth, mortality, recruitment and yield-per-recruit of Oreochromis niloticus from Garmat Ali River, Basrah, Iraq from October 2019 to September 2020. The population parameters were analyzed using the FAO-ICLARM stock assessment tool (FiSAT). A total of 2696 O. niloticus ranged from 7.0 to 25.0 cm and the sizes 13.0-18.0 cm constituted 64.2% of the total catch. The length-weight relationship was W= 0.012L3.109 suggesting that the species shows positive allometric growth. The growth parameters for the species were estimated as L∞= 30.45 cm, K= 0.45, to= -0.313 and Ǿ= 2.622. The coefficients of total mortality (Z), natural mortality (M) and fishing mortality (F) were 3.26, 1.03 and 2.24, respectively. The exploitation rate for the species computed to be 0.69. Fish were recruited to the fishery at a mean size of L50= 14.92 cm. The peak of recruitment was 23.51% in June. The analysis of yield-per-recruit (Y/R’) indicates that stock is not being overfished since the present exploitation rate was below the biological target reference points (E0.1 and Emax). So, more yields could be achieved by reducing the mesh sizes of the nets for fishing the species


2003 ◽  
Vol 4 (1) ◽  
pp. 87 ◽  
Author(s):  
S.M. ALLAM

Age and growth of Boops boops(L.) from the Mediterranean Sea off Alexandria were estimated from scales. No significant difference in growth was found between male and female. Back-calculated lengths at annulus formation for combined sex were 10.97, 14.03, 16.39, 18.56 and 20.51cm TL. The estimated von Bertalanffy growth parameters were L ‡ = 31.68 cm, K = 0.1531 year -1 and t Ζ = -1.7838.The length-weight relationship was W = -2.1548L 3.1031 . Total mortality (Z), natural mortality (M) and fishing mortality (F) were 1.283, 0.458 and 0.824 year -1 respectively. The exploitation rate (E) was 0.464. A Beverton-Holt yieldper- recruit model indicated that the maximum yield-per-recruit was 21.06 g when fishing mortality was 2.4 and the current fishery harvests approximately 95% of the potential yield.


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