Spatially integrated modelling of data-limited orange roughy (Hoplostethus atlanticus) using environmental covariates

2021 ◽  
Author(s):  
Charles Thomas Thesen Edwards ◽  
Marie-Julie Roux ◽  
Malcolm Ross Clark
Keyword(s):  
Stock Assessment ◽  
Spatial Modelling ◽  
Model Fit ◽  
Integrated Modelling ◽  
Limited Data ◽  
Orange Roughy ◽  
Environmental Covariates ◽  
The Relationship ◽  
Data Requirements ◽  
Hoplostethus Atlanticus

Spatial stock assessment models are recognised as increasingly important for estimation of stock status and a sustainable exploitation rate. The inclusion of movement between spatial units within a model is difficult, because the data requirements are high. However for populations with low levels of spatial exchange it is possible to reduce the data requirements by distributing information on biological parameters between neighbouring units, or units with shared environmental conditions. This can allow spatial modelling to be applied even in data-limited situations. We develop this approach here through application to orange roughy (Hoplostethus atlanticus) sub-populations inhabiting neighbouring seamounts in the South Pacific. Despite limited data for each seamount, we were able to simultaneously fit multiple, localised, process-based models of the depletion dynamics. This was achieved by sharing information on the unexploited population size via known environmental covariates, with the relationship estimated in a hierarchical and integrated manner during the model fit. Cross-validation demonstrated that this approach can compensate for a lack of seamount-specific abundance data and improve ability of the model to estimate localised depletions.

Fecundity and Gonado-somatic Index of Trichiurus lepturus (Linnaeus, 1758) Along the Zamboanga del Norte Coast

2018 ◽  
Vol 6 (7) ◽  
pp. 120
Author(s):  
Ma. Dulce C. Guillena
Keyword(s):  
Sex Ratio ◽  
Stock Assessment ◽  
Chi Square ◽  
Moon Phases ◽  
Ovary Weight ◽  
Moment Coefficient ◽  
Trichiurus Lepturus ◽  
Significant Difference ◽  
The Relationship ◽  
Somatic Index

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce.  This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used.  Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively.   Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference.  Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases.  Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity.  The results of this study could be used further for formal stock assessment of cutlassfish fishery.

scholarly journals The Effect of Sex and Age on Bone Morphology and Strength in the Metacarpus and Humerus in Beef-Cross-Dairy Cattle

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 694
Author(s):  
Michaela Gibson ◽  
Rebecca Hickson ◽  
Penny Back ◽  
Keren Dittmer ◽  
Nicola Schreurs ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Quantitative Computed Tomography ◽  
Live Weight ◽  
Peripheral Quantitative Computed Tomography ◽  
Bone Size ◽  
Limited Data ◽  
Bone Morphology ◽  
Relationship Of ◽  
The Relationship ◽  
Effect Of Age

In cattle, limited data have been reported about the relationship between live weight, bone size, and strength and how this relationship can be altered by factors such as sex and age. The aim of this study was to describe the relationship of peripheral quantitative computed tomography (pQCT)-derived parameters of bone strength and morphology with live weight, age and sex in beef-cross-dairy cattle. All animals were weighed the day before slaughter. The metacarpus and humerus were collected at slaughter and scanned at the mid-diaphysis using pQCT. Live weight was the primary explanatory variable for bone size and strength in all cohorts. However, the effect of age was significant, such that magnitude of response to liveweight was less in the 24-month-old cohort. Sex was significant within cohorts in that bulls had a shorter metacarpus than steers and heifers had a shorter metacarpus than steers at age of slaughter.

scholarly journals A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production

2011 ◽  
Vol 68 (3) ◽  
pp. 528-536 ◽  
Author(s):  
Miguel Bernal ◽  
Yorgos Stratoudakis ◽  
Simon Wood ◽  
Leire Ibaibarriaga ◽  
Luis Valdés ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Environmental Variables ◽  
Egg Production ◽  
Stock Assessment ◽  
Production Model ◽  
Estimation Methods ◽  
Statistical Framework ◽  
Spatio Temporal ◽  
The Relationship ◽  
Made In

Abstract Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production. – ICES Journal of Marine Science, 68: . A spatially and environmentally explicit egg production model is developed to accommodate a number of assumptions about the relationship between egg production and mortality and associated environmental variables. The general model was tested under different assumptions for Atlanto-Iberian sardine. It provides a flexible estimator of egg production, in which a range of assumptions and hypotheses can be tested in a structured manner within a well-defined statistical framework. Application of the model to Atlanto-Iberian sardine increased the precision of the egg production time-series, and allowed improvements to be made in understanding the spatio-temporal variability in egg production, as well as implications for ecology and stock assessment.

Fecundity Comparisons for Various Stocks of Lake Whitefish, Coregonus clupeaformis

1975 ◽  
Vol 32 (3) ◽  
pp. 404-407 ◽  
Author(s):  
M. C. Healey ◽  
C. W. Nicol
Keyword(s):  
Northwest Territories ◽  
Lake Erie ◽  
Fork Length ◽  
Nonlinear Relationship ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Limited Data ◽  
Relative Fecundity ◽  
Great Slave Lake ◽  
The Relationship

We found no significant differences in slope or intercept for the regression of loge fecundity on loge fork length among samples of whitefish from four lakes near Yellowknife in the Northwest Territories. The equation describing the relationship between fecundity and fork length for these populations was:[Formula: see text]Five other populations for which length–fecundity relationships could be calculated had length exponents ranging from 3.20 to 4.38, suggesting a nonlinear relationship between weight and fecundity. Six of the nine populations as well as four others for which limited data were available all had similar relative fecundities. Fish from Buck Lake in Alberta and from Lake Erie had high relative fecundities while fish from Great Slave Lake had low relative fecundity.

Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient

1985 ◽  
Vol 42 (5) ◽  
pp. 989-998 ◽  
Author(s):  
G. H. Winters ◽  
J. P. Wheeler
Keyword(s):  
Stock Assessment ◽  
Population Decline ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Population Abundance ◽  
Commercial Catch ◽  
Standard Manner ◽  
Clupea Harengus Harengus ◽  
The Relationship ◽  
Stock Abundance

The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA−b. For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock.

Knowledge management implementation in Indian automobile ancillary industries

2016 ◽  
Vol 11 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Nitin Yashwant Patil ◽  
Ravi M. Warkhedkar
Keyword(s):  
Knowledge Management ◽  
Industrial Area ◽  
Total Quality ◽  
Limited Data ◽  
Interpretive Structural Modeling ◽  
Content Type ◽  
Relationship Of ◽  
Power And Dependence ◽  
The Relationship

Purpose In the past decade, much has been written about knowledge management (KM) in the manufacturing; however, less attention has been paid to the Indian automobile ancillary industries located in Chinchwad, Pune. It is suitable to find out the relationship of the factors of the study. It helps in identifying the hierarchy of factors to be taken, and interlinking of production department with KM improves the productivity of the industries. Categorization of these principles based on their driving power (principles which hold other principles) and dependence (principles which are dependent on other principles) has also been examined for KM implementation to study the driving power and dependence power of these principles. This paper aims to determine the roadmap of KM implementation and categorize KM principles based on their driving power for manufacturing industries with the use of the interpretive structural modeling (ISM)-based model. The results indicate that the principles possessing higher driving power, such as KM, inventory control, quality control, productivity and scheduling and their interlinking. The major contribution of this research lies in the development of contextual relationship among various identified factors of KM and determination of their driving and dependence power through a single systemic framework. Design/methodology/approach In this paper, author find out the suitability ISM for Indian Automobile industries to find the relation among the variables. Findings ISM model has been developed for the hierarchy of the identified KM. As ISM model results a hypothetical hierarchy which needs a proper quantitative analysis to evaluate their percentage effectiveness in the hierarchy. Research limitations/implications It is applied to automobile industries with limited number of variables that will show the dependence variable and driving variables and their interrelations. It can be applied other fields to fine the relationship of variables. Practical implications The ISM may be used in supply chain management and total quality management to find interlinking between the variables. Originality/value The limited data collected from Pimpri Chinchwad industrial area of Pune from Maharashtra state (India).

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