scholarly journals Length-based estimates of growth parameters and mortality rates of fish populations from a coastal zone in the Southeastern Brazil

2018 ◽  
Vol 35 ◽  
pp. 1-8
Author(s):  
Marcus Rodrigues da Costa ◽  
Rafael de Almeida Tubino ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Coastal Zone ◽  
Growth Parameters ◽  
Linear Regression Analysis ◽  
Total Mortality ◽  
Mortality Rates ◽  
Fish Populations ◽  
Southeastern Brazil ◽  
Small Scale ◽  
Total Length ◽  
Management And Conservation

Small-scale fisheries in Brazil contribute to a significant share of total fish production, accessing a large variety of species. Life history parameters from these resources are important for their management and conservation, based on primary data. The objective of this article is to generate growth parameters and mortality rates of ten fish populations from a coastal zone in Southeastern Brazil. Monthly samples were taken between January 2011 and November 2014 from landings of the beach-seine fishery in an area adjacent to the entrance of the Guanabara Bay. All fishes were measured (total length) and weighed. The length-weight relationships (LWR) were estimated by linear regression analysis on log-transformed data of the equation: W = aLb. The Von Bertalanffy Growth Function (VBGF) was fitted to size-at-age data to obtain growth parameters (K, L∞). The length-converted catch curve was used for estimating the instantaneous total mortality (Z). Taylor’s equations provided an independent estimate of the natural mortality (M) and longevity. The difference between Z and M derived Fishing mortality (F). A total of 2,938 individuals from ten fish species were used to determine the length-weight relationships. Harengulaclupeola (Cuvier, 1829) has a new maximum length record for the FishBase LWR database. Sardinellabrasiliensis (Steindachner, 1879) presented the smallest and largest size recorded for LWR observed in the literature and FishBase database. Upeneusparvus showed the greatest total length, while Trichiuruslepturus Linnaeus, 1758, Orthopristisruber (Cuvier, 1830) and Dactylopterusvolitans (Linnaeus, 1758) presented the smallest sizes for LWR in FishBase. The other species showed parameters within the expected values for each group. The performance index combining information from K and L∞ presented values between 2.32 and 3.76 and were considered appropriate for the populations evaluated. Fishing was the primary source of mortality for Caranxcrysos (Mitchill, 1815), Eucinostomusargenteus Baird & Girard, 1855, S.brasiliensis and U.parvus, and less important for Cynoscionjamaicensis (Vaillant & Bocourt, 1883), D.volitans, O.ruber, Selenesetapinnis (Mitchill, 1815), T.lepturus and H.clupeola. The parameters generated may be used for the management and conservation of the species’ stocks.

scholarly journals Age, Growth and Mortality of the Common Carp (Cyprinus carpio) Population in Merdja Sidi Abed Dam, Algeria.

Omni-Akuatika ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 39
Author(s):  
BENSAHLA TALET Lotfi ◽  
Ahmed BENSAHLA TALET
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Condition Factor ◽  
Growth Parameters ◽  
Total Mortality ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Population Total ◽  
Total Length ◽  
The Common

We tried to estimate age, growth parameters, condition factor, length-weight relationship and mortality rates (Z, M, and F) of the common carp in Merdja Sidi Abed dam. Cyprinus carpio specimens were captured by long line between April and June 2013 in Merdjea Sidi abed. 220 individuals were collected and weights ranged between 265.5 and 620.3 g while the total length ranged between 26.3 and 35.6 cm. Length-converted catch curve was used to estimate total annual instantaneous mortality rates (Z), natural mortality was calculated using Pauly formula [ln(M) = -0.0152 - 0.279 ln(L∞) + 0.6543 ln(K) + 0.463 ln(T)]. Recruitment patterns were determined from the routine implemented in FISAT II. For all individuals (n = 220) of the common carp, the relationship between total length and body weight was: W = 0.0384 L2.70 (r2 = 0.906) for females and W = 0.0467 L2.653(r2 = 0.976) for males a minor allometry was found for this species, mean condition factor K was estimated at 1.41. The maximum value of recruitment was recorded in March-April period with 19.56 and 15.20 % respectively. The Battacharya method was used to estimate age of individuals that was comprised between 1 and years 3. The equation of Von Bertalanffy growth was: L = 36.75 [1-e-0.46 (t + 0.33)] for all the population. Total mortality (Z), natural mortality (M) and fishing mortality (F) were as follows: Z = 1.08, M = 0.82, F = 0.26 yr-1while exploitation ratio (E) was evaluated at 0.24 indicating an under exploitation of this local resource.

Age, growth and mortality of the garfish, Belone belone (L. 1761) in the Adriatic Sea

2012 ◽  
Vol 93 (2) ◽  
pp. 365-372 ◽  
Author(s):  
Barbara Zorica ◽  
Vanja Čikeš Keč
Keyword(s):  
Adriatic Sea ◽  
Growth Parameters ◽  
Fork Length ◽  
Mortality Rates ◽  
Von Bertalanffy ◽  
Positive Allometry ◽  
Von Bertalanffy Model ◽  
Total Length ◽  
Belone Belone ◽  
Conservation And Management

A sample of 3393 garfish, Belone belone (Linnaeus, 1761) was captured using a seine net between January 2003 and December 2008, along the eastern Adriatic Sea. The range in total length was 20.8–75.4 cm and in weight was 12.21–639.25 g. Length–length equations for converting size measurements (standard length and fork length to total length (TL)) were linear. In the length–weight relationship, positive allometry was established (b = 3.4818). Age, determined from sagittal otoliths, ranged from 1+ to 8+ years. The estimated von Bertalanffy model growth parameters for garfish were L∞ = 90.3 cm, K = 0.158 year−1, t0 = −0.109. Otolith weight was endorsed as a possible age predictor, as it showed highly exponential correlation with total garfish length and age (Wo = 0.0012 TL2.189; Wo = 0.568t1.486). These findings were used to examine mortality rates and exploitation in order to improve conservation and management of this pelagic species.

Estimating some population parameters and stock assesment of spiny butterfly ray, Gymnura altavela (Linnaeus, 1758) the Levant Basin coast (Northeastern Mediterranean)

2018 ◽  
Author(s):  
Hacer Yeldan
Keyword(s):  
Coastal Waters ◽  
Linear Regression Analysis ◽  
Total Mortality ◽  
Growth Function ◽  
Fishing Mortality ◽  
Total Length ◽  
Disc Width ◽  
Von Bertalanffy Growth Function ◽  
Exploitation Rate ◽  
Levant Basin

The purpose of this study was to investigate the morphometric characteristics, growth, mortality and exploitation rate of the spiny butterfly ray (Gymnura altavela Linnaeus, 1758). The study was conducted using 284 specimens from the coastal waters of the Levant Basin (the northeastern Mediterranean). Samples were collected monthly between July 2014 and June 2015 using a bottom trawl from the following depth strata: 0-10m, 10-20m, and 20-50m. The following measurements were taken total length (TL), disc length (DL), disc width (DW) distance from nose tip to eye (NE), nose tip to mouth (NM, cm), width of mouth (MW, cm) where Y is the various dimensions (TL; W; DL; DW; NE; NM; MW, respectively) and X is the total length estimated by linear regression analysis. Length-weight and disc width-weight relationships were W = 0.097 * TL3.2070 and W = 0.084 * DW3.169 for total individuals. The von Bertalanffy growth function contained in DW was DW¥ = 136.50cm K = 0.230 year-1 t0= -0.492year-1 for total individuals. The total mortality (Z) was 0.91year-1, the natural mortality (M) was 0.41year-1, and the fishing mortality (F) was estimated to be 0.51year-1. The exploitation rate (E) was calculated as 0.55 year-1 for all obtained individuals.

Some Simple Methods of Estimating Mortality Rates of Exploited Fish Populations

1973 ◽  
Vol 30 (5) ◽  
pp. 695-698 ◽  
Author(s):  
G. W. Ssentongo ◽  
P. A. Larkin
Keyword(s):  
Total Mortality ◽  
Mortality Rates ◽  
Fish Populations ◽  
The Mean ◽  
Simple Equations

Some simple equations are derived from mortality functions that enable estimation of the total mortality coefficient from the mean age and the age of first capture, or the mean length and the length of first capture, of fish in a catch.

scholarly journals Fluctuations in the spawning stock biomass and recruitment of the Brazilian sardine (Sardinella brasiliensis) 1977-1997

2002 ◽  
Vol 50 (unico) ◽  
pp. 13-26 ◽  
Author(s):  
Maria Cristina Cergole ◽  
Suzana Anita Saccardo ◽  
Carmen L. D. B. Rossi-Wongtschowski
Keyword(s):  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Commercial Fishing ◽  
Total Length ◽  
Length Relationship ◽  
Stock Biomass ◽  
Historical Series ◽  
Spawning Stock ◽  
Acoustic Surveys

In the southeastern coast of Brazil, catches of the Brazilian sardine (Sardinella brasiliensis) have been decreasing from more than 200 thousand tons/year in the early '70s to about 32 thousand tons in 1990. From 1994 to 1997, catches recovered slightly (118 thousand tons), dropping then to about 20 thousand tons in 1999-2000. Extensive investigations on biology and stock assessment of Brazilian sardine have been developed in the '80s, providing stock biomass and recruitment estimates based on commercial fishing data obtained from 1977-1992. The present paper aims to update biological and stock assessment parameters from sardine data obtained during two acoustic surveys carried out in 1995 and commercial catches from the 1993-1997 period. Results from both cruises showed the weight-length relationship Wt=0.0000019. Lt3,26 (90-240 mm total length) and four age classes (mostly class II+). In the commercial catches, sardines belonged to ages 0+ and 3+ years old (mostly older than 1-year old) with 90-250 mm total length. Annual growth parameters were: Li=275 mm, K= 0.55 (1996), and Li=273 mm, K=0.50 (1997). Total mortality (Z) and natural mortality (M) coefficients were: Z= 3.8; M= 0.7 -1.2 (1996), and Z= 3.6; M= 0.6 - 1.1 (1997). The variation amplitude of M is due to the application of several different methods. Considering the historical series of 21 years of data (1977-1997), results showed that the stock went through two favorable periods (1980-84, 1989-94) and one unfavorable period (1985-89). 1997 seems to have been the beginning of a new unfavorable period, revealing recruitment cycles likewise other stocks from California and Japan.

scholarly journals Population characteristics and exploitation of yellowfin tuna (Thunnus albacares Bonnaterre, 1788) in the coastal waters of Kenya

2021 ◽  
Vol 20 (1) ◽  
pp. 95-109
Author(s):  
Edward Kimakwa ◽  
Micheni Ntiba ◽  
Agnes Muthumbi
Keyword(s):  
Coastal Waters ◽  
Growth Parameters ◽  
Total Mortality ◽  
Mortality Rates ◽  
Yellowfin Tuna ◽  
Population Characteristics ◽  
Thunnus Albacares ◽  
Catch Per Unit Effort ◽  
Length Frequency ◽  
South West Indian Ocean

Yellowfin tuna, Thunnus albacares (Bonnaterre, 1788) is a highly migratory and important commercial fishery species. Data on length-frequency, growth parameters and mortality rates of yellowfin tuna in the coastal waters of Kenya is limited. We assessed Catch Per Unit Effort (CPUE), size distribution, growth parameters and mortality rates based on length-frequency and catch data collected from August 2015 to December 2016 at five fish landing sites along the Kenyan coast. The sample comprised of 1281 individuals of yellowfin tuna weighing 12,671 kg. Highest CPUE was recorded in October 2015 (10.8 kg·Fisher-1Trip-1) and lowest CPUE, 2.6 kg·Fisher-1Trip-1 in December 2016. Yellowfin tuna was more abundant in the South-East Monsoon (SEM), from May to October, with an average CPUE of 7.3 kg Fisher-1Trip-1 compared to North East Monsoon (NEM), from November to April, with a CPUE of 7.0 kg Fisher-1Trip-1. Spatial variation of CPUE was evident. Old Town recorded the highest CPUE of 54.2 kgTrip-1, while Mnarani the lowest of 19.4 kgTrip-1. At least 91 % of the fish sampled were < 100 cm FL and hence not yet mature. The asymptotic Length (L∞) was found to be 195 cm FL, the Von Bertalanffy growth constant (K) 0.43 year-1, t0 - 0.82 and the Growth Performance Index (f) 4.21. The total mortality coefficient (Z) was 2.59 year-1 , Natural Mortality (M) 0.59 year-1, Fishing Mortality (F) 2.00 year-1 and Exploitation Rate (E) 0.77 year-1. Results show that mortality and exploitation rates were above the optimal, indicating high fishing pressure on coastal yellowfin tuna. The information generated by this study provides some further insights on the scientific knowledge of the coastal yellowfin tuna to inform policy for sustainable management and development of this fishery in Kenya and the entire South West Indian Ocean (SWIO) region.

Less known aspects of Penaeus kerathurus (Forskål, 1775) (Decapoda, Penaeidae) obtained from the fishermen in the Sea of Marmara: age, growth, and mortality rates

Crustaceana ◽  
2020 ◽  
Vol 93 (9-10) ◽  
pp. 1185-1195
Author(s):  
M. Arslan İhsanoğlu
Keyword(s):  
Growth Parameters ◽  
Economic Value ◽  
Age Groups ◽  
Length Distribution ◽  
Total Mortality ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Sea Of Marmara ◽  
Age Composition ◽  
Important Species

Abstract Penaeus kerathurus is an important species for the fishery, thanks to its high nutritional and economic value. Therefore, this study attempts to determine the length distribution, length-weight relationship, age composition, growth parameters, and mortality rates of a population of P. kerathurus. The material was monthly collected from commercial fishermen in and around Karabiga and the Gulf of Erdek in the Sea of Marmara, between May 2018 and April 2019. The carapace length-weight relationships were calculated as W = 0.0023 × CL2.57, W = 0.0036 × CL2.46, and W = 0.0026 × CL2.56 for the females, males and both sexes combined, respectively. The population studied was distinguished into four age groups, and the tmax (= maximum theoretical age) was found to be reached at 11.9 year. The growth parameters were observed to be  = 60.9 mm; K = 0.24 year−1, and t0 = −0.58 year. The rates of total mortality (Z), natural mortality (M), fisheries mortality (F), and exploitation (E) were calculated to be 1.32, 0.43, 0.89, and 0.67, respectively. The results showed that P. kerathurus suffers from a heavy fishing pressure in the sampled area.

scholarly journals Growth and mortality of Cachana (Cynopotamus atratoensis) in the cienaga Grande de Lorica, Colombia

2015 ◽  
pp. 5028-5036
Author(s):  
Charles Olaya-Nieto ◽  
Fredys Segura-Guevara ◽  
Antonio Vergara-Paternina
Keyword(s):  
Growth Rate ◽  
Total Mortality ◽  
Fishing Mortality ◽  
Total Length ◽  
Exploitation Rate ◽  
Basic Biology ◽  
Management And Conservation ◽  
Biology Research ◽  
Average Catch ◽  
Length Frequency Analysis

ABSTRACT Objective. Growth and mortality parameters of Cachana Cynopotamus atratoensis Eigenmann, 1907 in the cienaga Grande de Lorica, Sinu river basin, Colombia, were estimated. Materials and methods. The length frequency analysis to the information collected between January 2001 to December 2002, was applied. Results. The estimated values for asymptotic length, growth rate and age at zero length were 43.4 (±0.52) cm of total length, 0.29 (±0.02) year-1 and -0.53 years, respectively. Total mortality was estimated at 0.97 year-1, natural mortality at 0.72 year-1, fishing mortality at 0.25, the average catch size was 24.8 cm total length, being fully recruited to the fishery with 16.6 cm total length, with low exploitation rate (E: 0.26). Conclusions. Cachana is a fish with medium longevity and growth rate with low exploitation rate, suggesting that there is still no overfishing on the species. However, as it is an very important fish in the food security of fishermen and their families, its necessary to increase the basic biology research pointing to the management and conservation of the species in the cienaga and the Sinu basin.

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