Corrigendum: A new likelihood for simultaneously estimating von Bertalanffy growth parameters, gear selectivity, and natural and fishing mortality

2011 ◽  
Vol 68 (8) ◽  
pp. 1507-1507 ◽  
Author(s):  
Nathan G. Taylor ◽  
Carl J. Walters ◽  
Steven J.D. Martell
Keyword(s):  
Growth Parameters ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Gear Selectivity

A new likelihood for simultaneously estimating von Bertalanffy growth parameters, gear selectivity, and natural and fishing mortality

2005 ◽  
Vol 62 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Nathan G Taylor ◽  
Carl J Walters ◽  
Steven J.D. Martell
Keyword(s):  
Growth Parameters ◽  
Fork Length ◽  
Simulated Data ◽  
Data Sets ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Size Selectivity ◽  
Gear Selectivity ◽  
History Of ◽  
Size At Age

Gear selectivity and the cumulative effects of size-selective fishing produce bias in the length-at-age samples used to estimate the von Bertalanffy growth parameters. In fished populations, fast-growing young fish and slow-growing old fish are overrepresented in size–age samples. To account for such effects, we treated size-at-age observations as multinomial samples, with expected catches in each size–age category dependent on growth parameters, growth variation, size selectivity, abundance at age, and the history of exploitation. Using simulated data sets, estimated growth parameters using the multinomial likelihood were unbiased when fishing mortality was not too high and the shape of the vulnerability function was correct. In contrast, estimated growth parameters using a least squares approach overestimated the metabolic growth coefficient (K) and underestimated mean asymptotic length (L∞). Models that do not explicitly account for the effects of fishing and size selectivity underestimated L∞ and overestimated K. We estimate growth parameters for northern pikeminnow (Ptychocheilus oregonensis) as an example of the method and document a stunted "pigmy" population with an L∞ of 175-mm fork length, attributing its small size to effects of high density and (or) a short growing season.

scholarly journals Age, growth and mortality of the European Seabass, (Dicentrarchus Labrax) in Bardawil lagoon, North Sinai, Egypt

2021 ◽  
pp. 042-046
Author(s):  
El-Desoki Menna O ◽  
Younis Younis M ◽  
A Youssef El-Dakar ◽  
Ahmed Salem M ◽  
Ahmed Kassem S ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Age Groups ◽  
Dicentrarchus Labrax ◽  
Mortality Rates ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
European Seabass ◽  
Exploitation Rate ◽  
The Relationship ◽  
North Sinai

Age, growth, and mortality of European Seabass (Dicentrarchus labrax) were studied from a small-scaled fishery of Bardawil lagoon, (North Sinai, Egypt). 181 specimens (16.6 to 35 cm total Length and 39.8 to 367.2 g total weight). The relationship between length and weight was W = 0.0054L3.1428. Age was determined by otoliths and age groups I to IV years were observed. Growths in length and weight at the end of each year were calculated. The growth parameters of von Bertalanffy equation were calculated as (L∞ = 48.69 cm, K = 0.1677 yr -1 and t0 = -0.447 yr -1). Growth performance index was calculated (φ = 2.60 for length and 1.25 for weight). Mortality rates were 0.867 yr-1, 0.25 yr1and 0.617 yr-1 for total, natural and fishing mortality, respectively. The currently exploitation rate E = 0.712 yr-1 indicating that, the population of this species is being heavily exploited.

Demographics of the endemic and threatened small cyprinid Pethia setnai from the Northern Western Ghats, India

2020 ◽  
Vol 71 (7) ◽  
pp. 810
Author(s):  
M. SriHari ◽  
Y. Gladston ◽  
S. M. Ajina ◽  
G. B. Sreekanth ◽  
Rajeev Raghavan ◽  
...  
Keyword(s):  
Western Ghats ◽  
Growth Parameters ◽  
Local Population ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Growth Coefficient ◽  
First Time ◽  
The Western Ghats

The indigo barb Pethia setnai is a threatened small cyprinid endemic to the Western Ghats biodiversity hotspot of India. In this study, the length–weight relationship and length–frequency-based population dynamics of this species, which are important prerequisites for effective fisheries management, were investigated for the first time based on specimens collected from the Mhadei River in the northern part of the Western Ghats. Estimated von Bertalanffy growth parameters were as follows: theoretical maximum length, L∞, 70.88 mm; growth coefficient, k, 1.50 year–1; and theoretical age at length 0, t0, –0.016 years. Natural mortality of P. setnai was higher than fishing mortality, and the present exploitation level (0.37) was less than 60% of the predicted maximum exploitation, suggesting that the species is not exploited to a level that is detrimental to the local population.

scholarly journals Age, growth, mortality, and exploitation rate of blueline snapper, Lutjanus coeruleolineatus (Actinopterygii: Perciformes: Lutjanidae), from Dhofar Governorate, Sultanate of Oman

2021 ◽  
Vol 51 (2) ◽  
pp. 159-166
Author(s):  
Dawood Almamari ◽  
Said Rabia ◽  
Joo Myun Park ◽  
Laith A. Jawad
Keyword(s):  
Fishery Management ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Sultanate Of Oman ◽  
Commercial Fish ◽  
Exploitation Rate ◽  
Reported Study

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.

scholarly journals Estimation of Fishing Mortality Rate and Exploitation Status of Yellowstrip Scad (Selaroides leptolepis) in Tomini Bay using Von Bertalanffy Growth Model Approach

2021 ◽  
Vol 13 (2) ◽  
pp. 288
Author(s):  
Nuralim Pasisingi ◽  
Faizal Kasim ◽  
Zulkifli Arsalam MoO
Keyword(s):  
Mortality Rate ◽  
Growth Model ◽  
Growth Parameters ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Female Fish ◽  
Male And Female ◽  
Fish Samples ◽  
Von Bertalanffy Growth Model ◽  
Exploitation Status

Highlight ResearchThe fishing area of S. leptolepis in this study was confirmed to be located in Tomini BayThe fish samples were gathered randomly from fishers’ catch using purse seinesThe growth curve for the male and female fish data were both plotted following the trend of the Von Bertalanffy equationThis study estimates the growth parameters, mortality, and exploitation rates of the male and female fish separately.AbstractComprehensive data is required for implementing sustainable fisheries management. Population dynamic and stock assessment aspects of Selaroides leptolepis species in Tomini Bay have not been entirely reported. This study aimed to determine the fishing mortality rate and exploitation status of S. leptolepis in Tomini Bay by calculating Von Bertalanffy growth model parameters (L∞, K, t0) then plotting them into Pauly's empirical equation. The sampling was conducted monthly from April to September 2020 at Gorontalo City Fishing Port. Samples were collected randomly from five commercial fishing vessels shortly after the fishermen landed their catch at the fishing port. All fish samples were confirmed to be obtained by the fishermen from Tomini waters. The growth parameters of the samples were analyzed using FiSAT II based on Von Bertalanffy mathematical model. While the mortality and exploitation values were calculated manually using Pauly's equation. The study showed that the growth parameter values of S. leptolepis in Tomini Bay were 245.47 mm, 0.49/year, and -3.04/year for males, while 227.80 mm, 0.63/year, and -2.72/year for females separately for L∞, K, and t0. The total, natural, and fishing mortality rates were 3.06/year, 0.61/year, and 2.45/year for males and 0.99/year, 0.74/year, and 0.25/year for females. The analysis results showed that the female's natural mortality (M) was higher than the male. In contrast, the fishing mortality (F) and total mortality (Z) of male fish exceed the female. The exploitation value of males (E=0.80) was greater than that of females (E=0.26).

scholarly journals Some biological properties of spiny eel (Mastacembelus mastacembelus, Banks & Solander, 1794) living in the Upper Euphrates River Basin, Turkey

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehmet Zülfü Çoban ◽  
Mücahit Eroğlu ◽  
Mustafa Düşükcan
Keyword(s):  
River Basin ◽  
Growth Parameters ◽  
Age Groups ◽  
Mortality Rates ◽  
Biological Properties ◽  
Von Bertalanffy ◽  
Growth Type ◽  
Euphrates River ◽  
Fish Samples ◽  
Exploitation Rate

AbstractThis study was carried out to determine some bioecological characteristics of Mastacembelus mastacembelus, which is the only species of Mastacembelidae family living in Turkey. Fish samples were caught between 2014–2018 from Keban Dam Lake, one of the most important reservoirs of the upper Euphrates Basin. In totally, 348 Mastacembelus mastacembelus individuals were examined, including 178 males and 170 females. The age distributions were defined between the I–XV age groups. Total lengths ranged from 14.20 to 81.80 cm in males and from 15.60 to 77.30 cm in females. Total length–weight relationships were calculated as W = 0.0083 × TL2.6516 for males, W = 0.0043 × TL2.8310 for females and W = 0.0063 × TL2.7256 for all population, and the growth type was estimated as “negative allometric”. The von Bertalanffy growth parameters for all individuals were computed as L∞ = 90.99, k = 0.13, t0 = − 0.45. The total (Z), natural (M), fishing (F) mortality rates and exploitation rate (E) were estimated as Z = 0.313, M = 0.270, F = 0.043 and E = 0.137, respectively. The length at first capture (Lc) was found as 50.72. The optimum, maximum and economic yields were calculated as E0.5 = 0.361; Emax = 0.776; E0.1 = 0.664, respectively.

scholarly journals Age and growth of the king mackerel (Scomberomorus Cavalla) off the northeastern coast of Brazil

2009 ◽  
Vol 57 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Marcelo Francisco de Nóbrega ◽  
Rosangela Paula Lessa
Keyword(s):  
Growth Parameters ◽  
Least Square Method ◽  
Least Square ◽  
Age And Growth ◽  
Northeastern Brazil ◽  
Von Bertalanffy ◽  
Growth Band ◽  
Marginal Increment ◽  
King Mackerel ◽  
Catch Composition

Age and growth of the king mackerel (Scomberomorus cavalla) were estimated for northeastern Brazil. A total of 405 sagittal otoliths from 140 males (24.4-112 cm), 73 females (28-114.8 cm) and 193 specimens of unknown sex (11.5-121 cm) were examined. Marginal increment analysis indicated an annual pattern for growth band deposition. The age classes ranged from 1 to 15 years. Length ranged from 11.5 to 121 cm. The Schnute model indicated that the von Bertalanffy growth model demonstrated the best adjustment, with p=1/b, and was therefore used for estimating growth. Back-calculated curves had smaller variances, giving the following estimated growth parameters for males: L∞= 116.8 cm, K = 0.190, t0 = 0.377; and females: L∞= 132.7 cm, K = 0.159 and t0 = 0.387. In order to compare the curves for males and females, the overlapping of 95% confidence intervals was performed for the parameters generated from the von Bertalanffy non-linear least square method. Specimens between 3 and 8 years of age represented 82.2% (n=5,783) of the catch composition, characterizing the species as a catchable stock in the region.

Movement, Growth and natural mortality rate of the Red Spot King Prawn, Penaeus longistylus Kubo, from the Great Barrier Reef Lagoon

1990 ◽  
Vol 41 (3) ◽  
pp. 399 ◽  
Author(s):  
MCL Dredge
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Great Barrier Reef ◽  
Annual Variation ◽  
Growth Parameters ◽  
Natural Mortality ◽  
Barrier Reef ◽  
Fishing Mortality ◽  
Nursery Areas ◽  
Reef Lagoon

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).

scholarly journals POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA

2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Lake Ecosystems ◽  
Exploitation Rate ◽  
Length Frequency Data

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.  

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