scholarly journals Age, growth, mortality and yield per recruit of the dourado Salminus brasiliensis, Corumbá Reservoir, Goiás State, Brazil

2009 ◽  
Vol 7 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Claudenice Dei Tos ◽  
Luiz Carlos Gomes ◽  
Angelo Antônio Agostinho ◽  
Rosana Paulo Batista

In order to evaluate the fate of the migratory species dourado Salminus brasiliensis in the first years of impoundment in Corumbá Reservoir we estimated age, growth, mortality and yield per recruit. Samplings were carried out monthly in Corumbá Reservoir and its main tributaries (Goiás State) from March 1998 to February 1999 using gillnets. After one year of impoundment, age was estimated from scales and the maximum number of rings was six for males and five for females. Rings are formed annually in May and June. The asymptotic length and growth rate for males and females were 37.1 cm and 0.77 and 56.6 cm and 0.52, respectively. A dominance of juveniles was verified in the reservoir and its tributaries. The instantaneous total mortality rate (Z) was 1.59 and the annual total mortality rate (A) was 79.6%. The highest yield per recruit (1200g) and the highest average weight (1900g) were obtained in simulations with low values of fishing (F) and natural (M) mortalities. Based on the above information we describe the Corumbá Reservoir impoundment has influenced the growth of the dourado. As regards this study, we recommend that the fishing effort not be applied during the trophic upsurge period and that the monitoring of the dourado assemblage continue. Fishery programs management for this species should be carried out with subsequent monitoring involving efficient communication, realistic practices and involvement of fisher organizations.

2003 ◽  
Vol 33 (4) ◽  
pp. 719-722 ◽  
Author(s):  
Sérgio Fonsêca Guimarães ◽  
Atílio Storti Filho

Matrinxã is a very promising amazonian fish for fish culture in Brazil. This study is aimed at determining the approximate tolerated temperature range in this species. Groups of ten young matrinxã specimens (15.1±0.8 cm average length and 58.3±10.3 g average weight) were subjected to 9 different temperatures for 24 hours without previous acclimation. Fish were transferred from an initial temperature of 27ºC to those ranging from 12 to 39ºC at 3ºC intervals. Both 12ºC and 39ºC temperatures were lethal for this species with 100% mortality rate. Following 2 minutes of exposure to 39ºC fish changed behavior, showing an increase in opercular movements and erratic swimming; mortality reached 100% after 18 minutes. At 12ºC, fish lost equilibrium immediately after exposure and started swimming erratically; after only 4 minutes fish became lethargic and remained immobile on the bottom of the tank. Total mortality was only evident following 24 hours. At 15ºC matrinxã lost equilibrium after 5 to 6 minutes of exposure but mortality was only 20% after 24 hours. Fish tolerated well temperatures ranging from 18 to 36ºC with 100% survival after 24 hours. This preliminary study suggests that temperatures between 18 and 36ºC are the approximate range normally tolerated by this species, although survival at other temperatures may be increased by gradually acclimating fish to the more severe increases or decreases in temperature. In addition, it indicates that matrinxã may be cultivated over a wide geographical area.


1995 ◽  
Vol 46 (3) ◽  
pp. 663 ◽  
Author(s):  
SA Shepherd ◽  
JL Baker ◽  
DW Johnson

The fecundity, size at sexual maturity, sex ratios and total mortality of Haliotis mariae on the Dhofar coast of the northern Arabian Sea were measured. These data, and estimates of the growth rate, were used for yield-per-recruit and egg-per-recruit analyses. Maximum yields occur at 3+ to 4+ years of age, depending on the natural mortality rate chosen. At the present age at first capture egg production levels are 2-29% of the unfished stock, depending on estimates of the fishing mortality rate and the natural mortality rate, and are considered to be far too low to maintain recruitment. At 40% egg production, of the maximum possible the age at first capture is 4 to 4.5 years, i.e. 105-115 mm shell length, depending on site.


2017 ◽  
Vol 9 (2) ◽  
pp. 85
Author(s):  
Umi Chodrijah ◽  
Ali Suman

Tingkat eksploitasi udang putih (Penaeus merguiensis) sangat intensif. Hal ini terindikasi dengan hasil tangkapan udang di WPP-NRI 716 selama 9 tahun terakhir meningkat. Tujuan penelitian ini untuk mengkaji beberapa parameter populasi dan aspek biologi udang putih di perairan Tarakan. Data panjang karapas dan tingkat kematangan gonad udang putih dikumpulkan dari tempat pendaratan udang di Selumit Pantai, Tarakan, Kalimantan Utara pada Januari sampai dengan November 2016. Pendugaan parameter populasi dengan aplikasi model analisis menggunakan program ELEFAN 1. Hasil penelitian menunjukkan rata-rata ukuran udang putih pertama kali tertangkap (Lc) pada panjang karapas 32,51 mm dan rata-rata ukuran pertama kali matang gonad 33,58 mm. Puncak musim pemijahan terjadi pada Maret dan Agustus. Laju pertumbuhan (K) sebesar 1,33 per tahun (betina) dan 1,55 per tahun (jantan). Laju kematian total (Z) sebesar 7,5 per tahun (betina) dan 8,85 per tahun (jantan), laju kematian alamiah (M) sebesar 1,82 per tahun (betina) dan 2,16 per tahun (jantan) serta laju kematian akibat penangkapan (F) sebesar 5,68 per tahun (betina) dan 6,69 per tahun (jantan). Laju pengusahaan (E) udang putih di perairan Tarakan adalah sebesar 0,76 per tahun. Hal ini menunjukkan tingkat pemanfaatan udang putih telah mengalami lebih tangkap (overfishing). Kondisi ini menggambarkan perlunya dilakukan pengurangan upaya sekitar 52 %.  The banana prawn (Penaeus merguiensis) have been exploited intensively. For instance, within nine years the number of shrimp production in FMA 716 increased dramatically. This research aims to identify the some population parameters of banana prawn in the Tarakan waters. This research was carried out from January to November 2016. Data were analyzed using the analytical model application with ELEFAN I. The result showed that the length at first capture (Lc) of banana prawn was 32,51 mmCL and the length at first maturity (Lm) was 33,58 mm CL. The peak season of spawning period was indicated on March and August. The growth rate (K) was 1,33 /year (female) and 1.55/year (male). Total mortality rate (Z) was 7.5/year (female) and 8,85/year (male), natural mortality rate (M) rate was 1.82/year (female) and 2.16/year (male) and fishing mortality rate ( F) were 5.68/ year (female) and 6.69/year (male). The exploitation rate (E) of banana prawn in the Tarakan waters was 0.76 per year. Therefore, level of existing fishing effort of the banana prawn should reduced about 52 % in the next year.


2013 ◽  
Vol 19 (2) ◽  
pp. 99 ◽  
Author(s):  
Duranta D. Kembaren ◽  
Ali Suman

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.


2016 ◽  
Vol 5 (4) ◽  
pp. 65-70
Author(s):  
Natalya Vitalievna Tochilkina

The article examines the impact of air pollution on the demographic characteristics of the residents of Saratov. It describes the main air pollutants that have a significant impact on the incidence of non-communicable diseases and child mortality. The author discusses the impact of complex index of air pollution and its components on overall mortality rates, mortality from cancer, respiratory diseases and the mortality rate of children under one year. The research has shown that there is a strong direct relationship between the complex index of air pollution and mortality from respiratory diseases and infant mortality rates. The author also reveals that the total mortality rate is closely associated with the increased content in the air of nitrogen oxide, the mortality rate from cancer with the increased content of nitrogen oxide and phenol, the mortality rate from respiratory diseases with excess of formaldehyde, the mortality rate of children under one year - with excess of formaldehyde and phenol. Despite the importance and relevance of such studies the author notes that it is difficult to access the information about morbidity by classes of diseases, by age and sex of the inhabitants of various administrative areas of the city. It does not enable a full analysis of the current situation and retrospective studies for its prediction.


2013 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
Zulkarnaen Fahmi ◽  
Syarifah Nurdawati ◽  
Freddy Supriyadi

Due to the economic importance of C. striata in Lubuk Lampam floodplains (Indonesia), this study is aimed to estimate the biological and population parameters required for proposing a future plan to sustain and manage this valuable fish resource. The growth, mortality and explotation ratio of <em>Channa striata</em> estimated by employing FiSATProgramme are reported. The parameters of Von Bertalanffy growth model of 1,529 sample fishes were estimated as K= 0.36/ year, L” = 72.98 cm and to = -0.52 year. The coefficients of total mortality (Z), natural mortality (M) and fishing mortality (F) were 1.72, 0.73 and 0.99 year-1 respectively. Relative yield per recruit analysis shows that the presentexploitation rate (E) was 0.58. Yield per recruit can be maximized at the exploitation ratio of 0.5 and Lc/Linf values of 0.3. The Yield per recruit and biomass per recruit models indicated that, the fisheries status of <em>C. striata</em> in Lubuk Lampam floodplains exceed the limit reference point (Fmax), thus stock of this species in Lubuk Lampam floodplains is indicated being driving down.Reduction in fishing effort and increase number of selective fishing gears are suggested to sustain the fishery of <em>Channa striata</em> in Lubuk Lampam floodplains.


2018 ◽  
Vol 23 (4) ◽  
pp. 227
Author(s):  
Dimas Angga Hedianto ◽  
Hendra Satria

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.


Author(s):  
M. S. M. Siddeek ◽  
R. Mohan ◽  
D. W. Johnson

The von Bertalanffy growth parameters estimated based on the 1990/91 carapace length data of Penaeus indicus  from the Gulf of Masirah, Oman were used to calculate total mortality, yield-per-recruit ( i.e. average weight of a shrimp from a cohort under a given fishing pattern) , and relative mean biomass ( i.e. exploited cohort biomass over un-exploited cohort biomass) for the population sampled. The instantaneous total mortality coefficient value indicated under exploitation in 1990/91. When different fishing seasons scenarios were considered with the current total mortality level but with a range of natural mortality values, high yield, per recruit and relative mean biomass values were shown for October-April and November-April fishing seasons. The fishing season is currently late August to end of April. Thus, a one to two-month delay in the fishing season appears to be beneficial to this fishery.


2021 ◽  
Vol 15 (6) ◽  
pp. 1917-1920
Author(s):  
Riffat Farrukh ◽  
Amber Naseer ◽  
Shaheen Masood ◽  
Ibrahim Shakoor ◽  
Farhina Nasir ◽  
...  

Aim: To estimate the incidence of ventilator-associated pneumonia (VAP) and to identify causing microbiological organismsand VAP related mortality rate in children admitted to the ICU. Study design: This was a Cross-sectional and an observational study. Study place and duration: In the Pediatric department of Abbasi Shaheed Hospital, Karachi, for one-year duration from May 2020 to May 2021. Methodology: All admitted children to the pediatric ICU (PICU) and ventilated were selected and observed for any features suggestive of VAP. All suspected children have Partial septic signs. A VAP will be categorized ifchild remains on ventilator for more than 48 hours and when a patient had 2 of these signs of nosocomial infection - TLC <4,000 or> 15,000 mm3 , fever> 101 ° F, CRP> 48 mg / L, neutrophils> 85% or a new chest X-rayexhibited pneumonia withradiological sign of progressive, persistent or new infiltrates. The chi-square test was used for comparison of percentages with a value of Less than 0.05 p. Results: Of all the cases admitted, the average length of ICU stay was 8.65 ± 6.45 per day. Children who needed VAP required 14.2 ±9.5 days of ventilation and 7.5± 5.2 days for children who have not VAP progression. Of 100 cohort of children necessitating ventilation, 22 died and 2 were left without advice or serious illness, with a total mortality of 22%. Conclusion: The VAP incidence in this study was 22%. Features related with a higher incidence of ventilator-associated pneumonia include age <1-year, continuous intravenous sedation and unplanned intubation in emergency situation. Features suggestive of underlying VAP encompassed, CRP> 48 mg / L, purulent tracheal secretions, positive tracheal culture of aspirate and positive X-ray results. Key words: Ventilator-associated pneumonia (VAP), Nosocomial infections,PICU and Children.


Author(s):  
Théophile Aké Bédia ◽  
Bakari Coulibaly ◽  
Yao Aristide Konan ◽  
Essetchi Paul Kouamelan ◽  
Valentin N’douba

The study evaluated some population parameters of Polydactylus quadrifilis within Ebrié lagoon (Potou sector). Samples were obtained using artisanal gillnet fishery from April 2004 to March 2006. A total of 741 individuals of P. quadrifilis ranged from 11 to 70 cm were examined. Population parameters were estimated where asymptotic length (L∞) was found 60 cm, growth rate (K) 0.33 per year, the longevity (T max) 9.09 years, and growth performance index (Φ′) 3.06. The length at first capture (Lc50 = 10.60 cm) was lower than the length at first maturity (Lm50 = 40 cm). Total mortality rate (Z) was calculated as 1.10 per year including natural mortality and fishing mortality. The exploitation rate (E=0.36) was found to be less than the maximum exploitation rate (E max = 0.44) and indicated that P. quadrifilis is not overexploited. The current exploitation rate should be maintained by sustainable fisheries measures including monitoring of fishing effort.


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