scholarly journals Population parameters of several groupers (Famili Serranidae) in Labuan Bajo waters, East Nusa Tenggara

2021 ◽  
Vol 919 (1) ◽  
pp. 012001
Author(s):  
P F Rachmawati ◽  
R Puspasari

Abstract Labuan Bajo has a fertile aquatic ecosystem, one of them is the coral reef ecosystem. This condition happened because of the supply of nutrients that are carried through Indonesia Through Flow and the local upwelling phenomena. Various species of reef fish of various sizes have been caught in Labuan Bajo waters. In general, the type of reef fish that dominates is grouper fish catch by using handline fishing gear. Furthermore, there is damage that occurs in the coastal ecosystem causes changes in ecological functions and disrupted ecosystem benefits. In addition, pressure from overuse did not provide opportunities for resources to carry out recovery makes the condition of resource stocks threatened. This study aims to determine the parameter aspects of the population of several types of grouper fish in Labuan Bajo waters. The types of grouper studied included Plectropomus leopardus, P. maculatus, P. oligacanthus, and Variola albimarginata. Data collection was carried out by enumerators from April to August 2019 which included the daily data on the length and weight distribution of groupers. Length-frequency distribution data is analyzed by estimating fish population parameters using the Electronic Length Frequency Analysis (ELEFAN I) program which is packaged in the FAO-ICLARM Stock Assessment Tool II (FiSAT II) software. The results of the analysis showed the equation of growth parameters for Von Bartalanffy for P. leopardus is Lt = 89.06(1-e−0.24(t+0.52)); P. maculatus is Lt = 76(1-e−0.54(t+0.23)); P. oligacanthus is Lt = 72.32(1-e−0.66(t+0.19)); and V. albimarginata is Lt = 45(1-e−0.51(t+0.29)). The length at first birth of each species is Lt=0 P. leopardus = 10.45 cm, Lt=0 P. maculatus = 8.88 cm, Lt=0 P. oligacanthus = 8.52 cm, and Lt=0 V. albimarginata = 6.19 cm. Meanwhile, the exploitation rate (E) of P. leopardus, P. maculatus, P. oligacanthus, and V. albimarginata were 0.81; 0.53; 0.45; and 0.70.

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.


2020 ◽  
Vol 19 (1) ◽  
pp. 51-57
Author(s):  
Stephen O. Ajagbe ◽  
Folashade. F. Ojo-fakuade

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


Author(s):  
Naciye Erdoğan Sağlam ◽  
Cemil Sağlam ◽  
Yeşim Demir Sağlam

The veined rapa whelk is one of the most important invasive species in the Black Sea ecosystem since the 1940s. Following its introduction to the Black Sea, it destroyed most of the bivalve populations, mainly the Mediterranean mussel and oysters. However, the veined rapa whelk has commercial importance for the Black Sea fisheries as an alternative product. In this study, we aimed to determine some population parameters of the veined rapa whelk based on indirect ageing through length–frequency data by using the Bhattacharya method. We collected 1704 specimens by dredging along the coasts of Samsun Province in the Central Black Sea in 2011 from June to November. The age of the population varied from 0 to 6. Von Bertalanffy growth parameters were estimated as L∞ = 112.35 mm, k = 0.310, t0 = −0.486 and W∞ = 243.94 g. Mean length and weight, length–weight relationship, mortality and exploitation rates were derived as L = 56.80 ± 0.36 mm, W = 45.67 ± 0.89 g, W = 0.0006 L2.719, Z = 0.96, M = 0.57, F = 0.39 and E = 0.40, respectively.


2005 ◽  
Vol 18 (1) ◽  
Author(s):  
K.K.U. AHMED ◽  
S.M.N. AMIN ◽  
G.C. HALDAR ◽  
S. DEWAN ◽  
M.M. HOSSAIN

The dynamics and stock assessment of Labeo rohita in Kaptai lake, Bangladesh are studied using length-frequency based analysis in order to evaluate growth parameters, mortality rates, exploitation rate, maximum sustainable yield (MSY) and the corresponding fishing pressure at this level. The study reveals that the fishery is harvested at a higher level than the optimum fishing pressure. This fishing pressure may be reduced near to 1.34/yr from the present level of fishing pressure 1.48/yr to obtain MSY of 51.90 tons.


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


Author(s):  
Idris Idris ◽  
E. Setyawan ◽  
A. Mardesyawati

<p>Marine ornamental reef fish trade is a huge industry with trade value USD 200-350 million/ year. Seribu Islands, Jakarta is one of the main ornamental reef fish catch area in Indonesia. The aim of this study was to compare ornamental fishing activities with total allowable catch (TAC). Ornamental reef fish catch data were collected from fishermen annually within 2007-2009, while reef fish population data are collected using underwater visual census every two years. The results showed that the total catch of 18 marine ornamental reef fish species exceeded TAC in 2007. Then there were 22 species in 2008 and 17 species of marine ornamental fish in 2009 that their catches were more than TAC. In addition, fish that are always included in the ten highest caught fish within 3 years were Cryptocentrus cinctus, Pomacentrus alleni, Pterosynchiropus splendidus, Premnas biaculeatus, and Amphiprion ocellaris. Their catches exceeded TAC.</p><p><br /><strong>Key words:</strong> Marine ornamental fish, Seribu Islands, Total Allowable Catch (TAC)</p>


2021 ◽  
Vol 9 (10) ◽  
pp. 1122
Author(s):  
Jia-Qiao Wang ◽  
Yi-Jia Shih ◽  
Liang-Ming Huang ◽  
Jun Li ◽  
Wei-Wen Li ◽  
...  

The quantitative evaluation of restocking and stock replenishment is essential for providing operational feedback and implementing adaptive management for future restoration projects. Since 2010, approximately 700 million juvenile shrimp (Penaeus penicillatus) have been released into Xiamen Bay, Fujian Province, China, each year, through stock replenishment programs. The recruited shrimp were sampled through three-year bottom trawl surveys from 2014 to 2017. The biological characteristics and catch equation were used to evaluate the effect of restocking and stock replenishment. The analysis uses the FAO-ICLARM Stock Assessment Tool (FISAT II) program. In general, there are two sources of recruitments—one from spawning brood stock and the other from released juvenile shrimp. We constructed an evaluation model for an effect evaluation based on Baranov’s catch equation to separate the initial recruitment volume using survey data. The relationship between body weight and total length was W =1.638 TL2.9307. There is no statistically significant difference between males and females. The von Bertalanffy growth parameters derived for prawns, using FiSAT II, were L∞ = 209.6 mm and K = 0.51 per year. In spring 2014, the initial resource amount was 49,200, while the ratio of effective recruitment and parent amount was 3.92. The survival rate of the released shrimp larvae, 1.88‱, seems to be very unsatisfactory. The resource amount in summer and autumn is higher than in winter and spring. Obviously, the restocking effect is lower and the programs need to be improved. To improve the restocking effect, the replenishment performance should be adjusted to reduce the mortality rate and increase its release effectiveness. Therefore, corresponding implementations are recommended, including standard extensive culture, reduction in stress during transportation, and temporary culture.


2015 ◽  
Vol 7 (3) ◽  
pp. 129
Author(s):  
Tegoeh Noegroho ◽  
Umi Chodrijah

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.


2006 ◽  
Vol 19 (1) ◽  
Author(s):  
M. ZAFAR ◽  
S.M. NURUL AMIN ◽  
M.M. RAHMAN

Population parameters of male and female Scylla serrata were estimated using FiSAT software with length-frequency data collected from different areas of Cox’s Bazar, southeastern part of Bangladesh (Chakaria Sundarban, Moheshkhali and Kutubdia channel) to evaluate the growth parameters, mortality rates and exploitation levels. Asymptotic length (L∝) was 105.9 mm and 105 mm, and growth co-efficient (K) was 0.28/yr and 0.36/yr for male and female S. serrata, respectively. The natural mortalities of S. serrata were 0.49/yr and 0.58/yr and fishing mortalities were 0.35/yr and 0.38/yr for male and female accordingly. Recruitment of this species into the fishery takes place throughout the year. The exploitation level for S. serrata was found to be 0.41 for the male and 0.39 for the female. This study showed that the stocks of male and female S. serrata were not under fishing pressure (E< 0.50) in the Southeastern part of Bangladesh.


Author(s):  
Yaris Hikmawansyah ◽  
Yuli Andriani ◽  
Alexander Muhammad Akbar Khan ◽  
Lantun Paradhita Dewanti

White pomfret (Pampus argenteus) is one of the economically important fish and includes the leading commodity in Pangandaran Waters. Information on fishing biology of those species were still limited. The purpose of this study is to determine stock estimates including length-weight relationship, age group, growth, mortality and exploitation rate of white pomfret. Monthly length-frequency data have been collected from November 2018 to August 2019 at Cikidang fish auction. Fish length-frequency distribution was separated into a normal distribution using the Bhattacharya method with software of FiSAT (FAO-ICLARM Stock Assessment Tools). Estimation of population parameters used analytical model application with ELEFAN-1 (Electronic Length Frequency Analysis) program. The results showed that lengths distribution of white pomfret ranged between 19.3 cm - 36.8 cmTL. Length-weight relations was negatively allometric (W = 0,1184L2,3719). Growth equation of white pomfret is Lt = 53.04 (1-e-0.26(t)). Natural mortality (M) was 0.60/year, fishing mortality (F) was 3.04/year and total mortality (Z) was 3.64/ year. The exploitation rate (E) was 0.84. It is mean that higher than optimal exploitation so that the white pomfret fish population in a state of overfished. It is necessary to better policy in the management of white pomfret through precaution approach and describing of biological and fishing aspect in Pangandaran Waters.


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