On the interrelationships between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks

1980 ◽  
Vol 39 (2) ◽  
pp. 175-192 ◽  
Author(s):  
D. Pauly
2016 ◽  
Vol 74 (5) ◽  
pp. 1256-1267
Author(s):  
Diego Valderrama ◽  
KathrynAnn H. Fields

Given its ability to yield predictions for very diverse phenomena based only on two parameters—body size and temperature—the Metabolic Theory of Ecology (MTE) has earned a prominent place among ecology’s efficient theories. In a seminal article, the leading proponents of the MTE claimed that the theory was supported by evidence from Pauly’s (On the interrelationships between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks. Journal Du Conseil International Pour L’Exploration de la mer 39:175–192) dataset on natural mortality, biomass, and environmental temperature for 175 fish stocks spanning tropical, temperate, and polar locations. We demonstrate that the evidence presented by the proponents of the MTE is flawed because it fails to account for the fact that Pauly re-estimated environmental temperatures for polar fish as ‘physiologically effective temperatures’ to correct for their ‘abnormally’ high natural (mass-corrected) mortalities, which on average turned out to be similar to (rather than lower than) the mortalities recorded for temperate fish. Failing to account for these modifications skews the coefficients from MTE regression models and wrongly validates predictions from the theory. It is important to point out these deficiencies given the broad appeal of the MTE as a theoretical framework for applied ecological research. In a recent application, the MTE was used to estimate biomass production rates of prey fish in a model of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) predation in Bahamian reefs. We show that the MTE coefficients may lead to a drastic overestimation of prey fish mortality and productivity rates, leading to erroneous estimations of target densities for ecological control of lionfish stocks. A set of robust mortality-weight coefficients is proposed as an alternative to the MTE.


2007 ◽  
Vol 64 (2) ◽  
pp. 249-255 ◽  
Author(s):  
David Griffiths ◽  
Chris Harrod

Pauly (1980. J. Cons. Int. Explor. Mer, 39: 175–192) showed that natural mortality rates in fish could be predicted from body growth parameters and environmental temperature but found no evidence for ecological or taxonomic influences. Using an updated database and techniques that avoid some of the earlier analytical problems, we confirm Pauly's conclusion that mortality is correlated with growth and temperature. A path model supports the role of ecological effects on mortality. A phylogenetic effect is also apparent: perciform fishes occupy warmer environments than other species, but in the predator-rich reef habitat they suffer much lower mortality rates. Species that are cryptic or hide in burrows or have morphological defences against predators show the lowest mortality rates.


Author(s):  
Dalilla da Silva Salvati ◽  
Júlia Fernandes Perroca ◽  
Sabrina Morilhas Simões ◽  
Antonio Leão Castilho ◽  
Rogerio Caetano da Costa

AbstractThe study characterized the structure of juveniles and sub-adults of Farfantepenaeus brasiliensis and F. paulensis in the Cananéia-Iguape estuarine lagoon system and its adjacent coastal area by evaluating the period of juvenile recruitment, sex ratio, growth, longevity, natural mortality, and development time until the late juvenile phase. Samples were collected from July 2012 to June 2014. Shrimps were identified by species and sex, and measured (carapace length – CL mm); 889 individuals of F. brasiliensis and 848 of F. paulensis were analysed. Females were more abundant than males for both species. The growth parameters of F. brasiliensis were: CL∞ = 45.5 mm, k = 1.8 year−1 for males and CL∞ = 55.2 mm, k = 1.6 year−1 for females; longevity of 2.52 years (males) and 2.88 years (females); and natural mortality of 1.71 (males) and 1.55 (females). For F. paulensis, the following values were observed: CL∞ = 40.7 mm, k = 2.3 year−1 for males and CL∞ = 56.5 mm, k = 1.9 year−1 for females; longevity of 2.04 years (males) and 2.37 years (females); and natural mortality of 2.39 (males) and 2.05 (females). The juvenile recruitment of both species peaked in January 2014. The development time until late juvenile phase was ~7 months (F. brasiliensis) and ~5 months (F. paulensis). Even though the highest abundance of juveniles did not occur in the closed season, fishing is forbidden in the estuarine area and the migration towards the adult population occurred close to or even during the closed season.


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).


2016 ◽  
Vol 67 (5) ◽  
pp. 578 ◽  
Author(s):  
Sondes Marouani ◽  
Hasna Kadri ◽  
Mohamed Nejmeddine Bradai

The occurrence of the piked spurdog (Squalus megalops) in the Gulf of Gabès (Tunisia, central Mediterranean Sea) was recently confirmed. The present study is the first to report the age, growth, longevity, natural mortality and size and age at maturity of this species in the Mediterranean Sea, precisely in the Gulf of Gabès. Marginal increment and edge analysis suggested annual band formation. Age estimates ranged from 0 to 26 and from 0 to 29 years for males and females respectively. Von Bertalanffy growth parameters derived from length-at-age data were: the theoretical asymptotic length L∞=82.31±1.55cm, the growth-rate coefficient k=0.06±0.003 years–1, the theoretical age at length zero t0=–3.89±0.25 years for females; and L∞=68.55±0.98cm, k=0.08±0.003 years–1, t0=–4.65±0.25 years for males. Males and females reached maturity at 44.36- and 56.41-cm total length, corresponding to 8.39 and 15.38 years respectively. Longevity estimates were 32.85 and 46.11 years for males and females respectively. On the basis of life-history parameters, natural mortality estimation M ranged from 0.14 to 0.17.


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.  


2005 ◽  
Vol 62 (7) ◽  
pp. 1626-1639 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford

The percentage of unfished lifetime egg production (LEP) has been used to represent persistence in precautionary fisheries management, but estimation of this reference point requires substantial data and it is sensitive to errors in natural mortality rate. We present an estimation method that quantifies the change in LEP by a fishery when only length frequency samples, one early in the fishery and one recent, are available for assessment. Using simulated length frequency data with known parameter values, estimates of LEP had undetectable bias when challenged with random sampling variability and sample sizes as low as 100. Simulation of artificial data with (i) growth parameters that differed from the estimation model, (ii) transient size structures, and (iii) recruitment variability led to predictably biased estimates. In a direct comparison with the spawning potential ratio reference point, fractional LEP was much less sensitive to errors in natural mortality rate. Application of this method to length frequency data for blue rockfish (Sebastes mystinus) for years between 1980 and 2003 suggests that during this interval, LEP has been reduced to levels of concern.


1980 ◽  
Vol 37 (12) ◽  
pp. 2266-2271 ◽  
Author(s):  
Donald R. Gunderson

Theory on r-K selection is used as a basis for examining correlations between instantaneous rate of natural mortality (M), gonad-body weight index, age at maturity, longevity, and Bertalanffy growth parameters (k, L∞) for 10 species of marine fish. All correlations were consistent with r-K selection theory. The gonad-body weight index was found to be more highly correlated with M than any of the other life history parameters examined (r2 = 0.62), and stepwise multiple regression showed that additional variables added little to the predictive ability of the model. The gonad-body weight index appears to be quite useful in predicting M, and development of an analogous index on an energetics basis might enhance its utility in this regard.Key words: natural mortality, r-K selection, life history parameters


2021 ◽  
Vol 2 (1) ◽  
pp. 16-23
Author(s):  
Joseph Aggrey-Fynn ◽  
Divine Worlanyo Hotor

Sphyraena sphyraena (Linnaeus, 1758) and Apsilus fuscus (Valenciennes, 1830) are commercially important fish species in Ghana. The stocks are exploited mainly by the artisanal and semi-industrial fisheries. Growth and mortality rates, and exploitation levels of the two stocks in inshore waters of Ghana were assessed as a contribution to fill the knowledge gap on the species. Samples were obtained from three landing sites along the coast of Ghana from February to July, 2017. Length-frequency data were used to estimate growth, mortality and exploitation ratios. The modal class for S. sphyraena was 37.0–39.9 cm total length (TL) and 34.0–35.9 cm TL for A. fuscus. The length and weight relationships established that growth in S. sphyraena was negative allometric, whereas that of A. fuscus was isometric. The estimated growth parameters from the length frequency data fitted with the von Bertalanffy growth function were asymptotic length (L∞) of 69.9 cm TL for S. sphyraena and 53.5 cm TL for A. fuscus. The growth constant (K) was calculated as 1.64 yr-1 for S. sphyraena and 0.50 yr-1 for A. fuscus. The mean length-at-first capture (Lc) was found to be lower than the mean length at sexual maturity (Lm) for both species. The sex ratio showed a dominance of females over males in S. sphyraena, and 1:1 for A. fuscus. The total mortality rate (Z) for S. sphyraena was more than for A. fuscus. The estimated natural mortality (M) was 1.88 yr-1 for S. sphyraena and 0.74 yr-1 for A. fuscus whilst fishing mortality (F) rate was 3.04 yr-1 for S. sphyraena and 0.93 yr-1 for A. fuscus. The exploitation ratio showed that both fish stocks were exploited over the optimum levels. The estimated population parameters of the species obtained from the study, therefore, might be useful for the sustainable management of the stocks.


1999 ◽  
Vol 50 (2) ◽  
pp. 103 ◽  
Author(s):  
P. L. Horn ◽  
R. J. Hurst

Age determination of gemfish by counting hyaline zones in otoliths was validated by following the progression of modes in length–frequency distributions and the progression of strong and weak year classes in age–frequency distributions. Length–frequency and otolith samples were examined from four areas (west Northland, east Northland and Bay of Plenty, Wairarapa coast, and the Stewart- Snares shelf). Age–frequency distributions and von Bertalanffy growth parameters were calculated and compared between areas. Two gemfish stocks are indicated on the basis of patterns of year class strengths, trends in commercial landings and likely spawning areas; one off the east and north of the North Island, and another off the west and south of the South Island. Estimates of natural mortality are presented for the two stocks.


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