Growth, Maturity, Fecundity and Mortality in the Relatively Unexploited Whitefish, Coregonus clupeaformis, of Great Slave Lake

1953 ◽  
Vol 10 (7) ◽  
pp. 413-441 ◽  
Author(s):  
W. A. Kennedy
Keyword(s):  
Mortality Rate ◽  
Sex Ratio ◽  
Commercial Fishing ◽  
Coregonus Clupeaformis ◽  
Gill Nets ◽  
Weight Relationship ◽  
Great Slave Lake ◽  
Obvious Change ◽  
The Relationship ◽  
Annual Mortality

Ages were determined of 6,571 whitefish for which sizes were recorded. A length-weight relationship, the percentage of both sexes mature at each age, the sex ratio, the proportion of mature females that spawn annually and the relationship between size of fish and number of eggs were determined from smaller samples.Growth rate is difficult to assess because of net selection, but it seems to be slower than in more southerly lakes. Growth appears to be limited to the period June to September inclusive.The total annual mortality rate of 61 per cent represents the unexploited condition—four years of commercial fishing with 51/2-inch mesh gill-nets produced no obvious change. A moderate mortality rate acting at all ages will easily account for thousands of eggs being produced for every whitefish that survives to maturity—it is unnecessary to assume a low percentage of eggs fertilized or excessive mortality among fertilized eggs or among young fish.A more intensive fishery would probably increase sustained yield.

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.

Tagging Returns, Age Studies and Fluctuations in Abundance of Lake Winnipeg Whitefish, 1931–1951

1954 ◽  
Vol 11 (3) ◽  
pp. 284-309 ◽  
Author(s):  
W. A. Kennedy
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Weather Conditions ◽  
Fishing Effort ◽  
Coregonus Clupeaformis ◽  
Lake Winnipeg ◽  
Equal Strength ◽  
Age Studies ◽  
Annual Mortality ◽  
Age Determinations

On the basis of 2,003 lake whitefish, Coregonus clupeaformis, tagged in 1938, of which 126 were recovered during the next five years, there is evidence that fish released together tend to stay together for years, and that the proportion of a population captured during a certain time by a unit amount of fishing effort can fluctuate greatly (a plausible explanation is the effect of variations in weather conditions). On the basis of age determinations of 12,975 whitefish in samples taken annually from 1937 to 1951, growth rate was determined, the total annual mortality rate among fully exploited fish was calculated to be 64 per cent over several years, and it appeared that all year-classes had been of about equal strength in recent years. The generally accepted idea that fluctations in fishing success correspond to fluctuations in abundance of whitefish is probably erroneous. Possibly the Lake Winnipeg whitefish are underfished.

The Relationship of Fishing Effort by Gill Nets to the Interval Between Lifts

1951 ◽  
Vol 8b (4) ◽  
pp. 264-274 ◽  
Author(s):  
W. A. Kennedy
Keyword(s):  
Fishing Effort ◽  
Relative Increase ◽  
Gill Nets ◽  
Great Slave Lake ◽  
Relationship Of ◽  
The Relationship ◽  
Made In

A description is given of the method used in analysing data from the Great Slave Lake summer fishing by which the fishing effort exerted by gill nets that are cleared every two, three, four or five days can be made comparable with the effort exerted by gill nets that are cleared daily. A comparison of catches made in 151 pairs of cases where gill nets were cleared daily and every two days under otherwise apparently identical conditions indicated that the greater the catch per net that can be made in nets that are cleared daily, the less will be the relative increase in catch per net when they are cleared every two days. It is possible to "saturate" nets after which they will catch no additional fish.

scholarly journals The Relationship Between Demographic, Socioeconomic, and Health-Related Parameters and the Impact of COVID-19 on 24 Regions in India: Exploratory Cross-Sectional Study (Preprint)

2020 ◽  
Author(s):  
Ravi Philip Rajkumar
Keyword(s):  
Mortality Rate ◽  
Sex Ratio ◽  
Multivariate Analyses ◽  
Case Fatality ◽  
Negatively Associated ◽  
Crude Mortality Rate ◽  
Crude Mortality ◽  
Health Related ◽  
The Impact ◽  
The Relationship

BACKGROUND The impact of the COVID-19 pandemic has varied widely across nations and even in different regions of the same nation. Some of this variability may be due to the interplay of pre-existing demographic, socioeconomic, and health-related factors in a given population. OBJECTIVE The aim of this study was to examine the statistical associations between the statewise prevalence, mortality rate, and case fatality rate of COVID-19 in 24 regions in India (23 states and Delhi), as well as key demographic, socioeconomic, and health-related indices. METHODS Data on disease prevalence, crude mortality, and case fatality were obtained from statistics provided by the Government of India for 24 regions, as of June 30, 2020. The relationship between these parameters and the demographic, socioeconomic, and health-related indices of the regions under study was examined using both bivariate and multivariate analyses. RESULTS COVID-19 prevalence was negatively associated with male-to-female sex ratio (defined as the number of females per 1000 male population) and positively associated with the presence of an international airport in a particular state. The crude mortality rate for COVID-19 was negatively associated with sex ratio and the statewise burden of diarrheal disease, and positively associated with the statewise burden of ischemic heart disease. Multivariate analyses demonstrated that the COVID-19 crude mortality rate was significantly and negatively associated with sex ratio. CONCLUSIONS These results suggest that the transmission and impact of COVID-19 in a given population may be influenced by a number of variables, with demographic factors showing the most consistent association.

Growth, Maturity and Mortality in the Relatively Unexploited Lake Trout, Cristivomer namaycush, of Great Slave Lake

1954 ◽  
Vol 11 (6) ◽  
pp. 827-852 ◽  
Author(s):  
W. A. Kennedy
Keyword(s):  
Significant Variation ◽  
Lake Trout ◽  
The Other ◽  
Commercial Fishing ◽  
Bear Lake ◽  
Great Slave Lake ◽  
Class Strength ◽  
Mature Size ◽  
Commercial Size ◽  
Annual Mortality

Ages of 9,215 lake trout were determined. Length-weight and time-maturity relationships are shown. Sex ratio is 1:1. Only half the females of mature size spawn each year. There is no growth except during June to September, inclusive. There is a tremendous difference in size at a given age. Growth is much faster in one half of the lake than in the other, it is the same as or slightly slower than in lakes farther south and considerably faster than in Great Bear Lake. Seven years of commercial fishing did not increase total annual mortality by much. Mortality rate increases with age among all fish of catchable size. A given year-class probably attains maximum biomass well before most of its members reach commercial size. No significant variation in year-class strength was found.

scholarly journals The Relationship Between Demographic, Socioeconomic, and Health-Related Parameters and the Impact of COVID-19 on 24 Regions in India: Exploratory Cross-Sectional Study

10.2196/23083 ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. e23083
Author(s):  
Ravi Philip Rajkumar
Keyword(s):  
Mortality Rate ◽  
Sex Ratio ◽  
Multivariate Analyses ◽  
Case Fatality ◽  
Negatively Associated ◽  
Crude Mortality Rate ◽  
Crude Mortality ◽  
Health Related ◽  
The Impact ◽  
The Relationship

Background The impact of the COVID-19 pandemic has varied widely across nations and even in different regions of the same nation. Some of this variability may be due to the interplay of pre-existing demographic, socioeconomic, and health-related factors in a given population. Objective The aim of this study was to examine the statistical associations between the statewise prevalence, mortality rate, and case fatality rate of COVID-19 in 24 regions in India (23 states and Delhi), as well as key demographic, socioeconomic, and health-related indices. Methods Data on disease prevalence, crude mortality, and case fatality were obtained from statistics provided by the Government of India for 24 regions, as of June 30, 2020. The relationship between these parameters and the demographic, socioeconomic, and health-related indices of the regions under study was examined using both bivariate and multivariate analyses. Results COVID-19 prevalence was negatively associated with male-to-female sex ratio (defined as the number of females per 1000 male population) and positively associated with the presence of an international airport in a particular state. The crude mortality rate for COVID-19 was negatively associated with sex ratio and the statewise burden of diarrheal disease, and positively associated with the statewise burden of ischemic heart disease. Multivariate analyses demonstrated that the COVID-19 crude mortality rate was significantly and negatively associated with sex ratio. Conclusions These results suggest that the transmission and impact of COVID-19 in a given population may be influenced by a number of variables, with demographic factors showing the most consistent association.

Fecundity length weight relationship and sex ratio in fresh water prawn Macrobrachium dayanum from Gho-Manhasan stream,Jammu, Jammu & Kashmir, India

2012 ◽  
Vol 2 (7) ◽  
pp. 533-534 ◽  
Author(s):  
Seema Langer ◽  
◽  
Krishan Raj Kant ◽  
Dr.Sumit Koul
Keyword(s):  
Sex Ratio ◽  
Fresh Water ◽  
Weight Relationship

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.

Secondary Sex Ratio, Body Weight and Length and Mortality Rate Among Infants

1951 ◽  
Vol 85 (823) ◽  
pp. 267-267
Author(s):  
Mohamed M. Oloufa
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Sex Ratio ◽  
Secondary Sex Ratio

Abstract P261: Intensive Systolic Blood Pressure Lowering Will Prevent Over 100,000 Deaths Annually

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Holly Kramer ◽  
Adam Bress ◽  
Srinivasan Beddhu ◽  
Paul Muntner ◽  
Richard S Cooper
Keyword(s):  
Blood Pressure ◽  
Mortality Rate ◽  
Systolic Blood Pressure ◽  
Mortality Rates ◽  
Mortality Data ◽  
Blood Pressure Lowering ◽  
Cvd Risk ◽  
Pressure Lowering ◽  
Annual Mortality ◽  
The U.S

Background: The Systolic Blood Pressure Intervention Trial (SPRINT) trial randomized 9,361 adults aged ≥50 years at high cardiovascular disease (CVD) risk without diabetes or stroke to intensive systolic blood pressure (SBP) lowering (≤120 mmHg) or standard SBP lowering (≤140 mmHg). After a median follow up of 3.26 years, all-cause mortality was 27% (95% CI 40%, 10%) lower with intensive SBP lowering. We estimated the potential number of prevented deaths with intensive SBP lowering in the U.S. population meeting SPRINT criteria. Methods: SPRINT eligibility criteria were applied to the National Health and Nutrition Examination Survey 1999-2006, a representative survey of the U.S. population, linked with the mortality data through December 2011. Eligibility included (1) age ≥50 years with (2) SBP 130-180 mmHg depending on number of antihypertensive classes being taken, and (3) presence of ≥1 CVD risk conditions (history of coronary heart disease, estimated glomerular filtration rate (eGFR) 20 to 59 ml/min/1.73 m 2 , 10-year Framingham risk score ≥15%, or age ≥75 years). Adults with diabetes, stroke history, >1 g/day proteinuria, heart failure, on dialysis, or eGFR<20 ml/min/1.73m 2 were excluded. Annual mortality rates for adults meeting SPRINT criteria were calculated using Kaplan-Meier methods and the expected reduction in mortality rates with intensive SBP lowering in SPRINT was used to determine the number of potential deaths prevented. Analyses accounted for the complex survey design. Results: An estimated 18.1 million U.S. adults met SPRINT criteria with 7.4 million taking blood pressure lowering medications. The mean age was 68.6 years and 83.2% and 7.4% were non-Hispanic white and non-Hispanic black, respectively. The annual mortality rate was 2.2% (95% CI 1.9%, 2.5%) and intensive SBP lowering was projected to prevent 107,453 deaths per year (95% CI 45,374 to 139,490). Among adults with SBP ≥145 mmHg, the annual mortality rate was 2.5% (95% CI 2.1%, 3.0%) and intensive SBP lowering was projected to prevent 60,908 deaths per year (95% CI 26, 455 to 76, 792). Conclusions: We project intensive SBP lowering could prevent over 100,000 deaths per year of intensive treatment.

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