Estimation of annual mortality rates caused by early mortality syndromes (EMS) and their impact on salmonid stock–recruit relationships

2006 ◽  
Vol 63 (9) ◽  
pp. 1968-1981 ◽  
Author(s):  
Catherine G.J Michielsens ◽  
Samu Mäntyniemi ◽  
Pekka J Vuorinen
Keyword(s):  
Atlantic Salmon ◽  
Probabilistic Approach ◽  
Mortality Rates ◽  
Early Mortality ◽  
Stock Recruitment ◽  
The Baltic ◽  
Meta Analyses ◽  
Annual Mortality ◽  
Mortality Estimates ◽  
Related Mortality

In this paper, we demonstrate how information from broodstocks can be combined with lab information on alevins to obtain annual stock-specific mortality estimates from early mortality syndromes (EMS) using a probabilistic approach, how a hierarchical model structure can be used to predict these mortality rates for related, partly sampled, or unsampled stocks, and why these estimates should be used to remove the effect of this mortality on stock–recruit estimates. The approach has been illustrated for Atlantic salmon (Salmo salar) stocks in the Baltic Sea affected by the M74 syndrome. Results indicate that data on the proportion of M74-affected females, commonly used to approximate M74 mortality, overestimate actual M74-related mortality because of a declining trend in mortality among offspring of these females. The stock-specific M74 mortality estimates are used to account for nonstationarity in the stock–recruitment relationship caused by this fluctuating mortality. Because hierarchical meta-analyses assume exchangeability, the effect of M74 mortality is removed before including these stocks within hierarchical stock–recruit analyses of Atlantic salmon stocks, which are commonly unaffected by M74 mortality. Failure to remove the effect of M74 mortality on the stock–recruit data results in underestimation of the stock's productivity and resilience to exploitation, especially in the case of stocks with steep stock–recruit curves.

Early Life Stage Mortality Syndrome in Fishes of the Great Lakes and Baltic Sea

1998 ◽  
Keyword(s):  
Baltic Sea ◽  
Salmo Salar ◽  
Early Life ◽  
Life Stage ◽  
Early Life Stage ◽  
Mortality Rates ◽  
Yolk Sac ◽  
The Mean ◽  
The Baltic ◽  
Related Mortality

<em>Abstract</em>.—Since 1974, feral salmon <em>Salmo salar </em>populations of the Baltic Sea have suffered from a yolk sac fry mortality known as the M74 syndrome. Mortality rates of 40–95% have been recorded during the 1990s in compensatory rearing stations along the east coast of Sweden. The M74 syndrome has been linked to the offspring of specific females and associated with low thiamine (vitamin B<sub>1</sub>) concentrations in both female tissues and their progeny. This study evaluated the effect of thiamine treatments on mortality and thiamine concentrations in progeny with and without M74. Eggs and newly hatched yolk sac fry were immersed in water containing thiamine at concentrations of 100, 500, or 2,000 mg/L. Hardening of eggs in water containing thiamine at 500 or 2,000 mg/L completely eliminated M74-related mortality, whereas treatment with thiamine at 100 mg/L only partially reduced M74 mortality. The mean thiamine concentrations at the yolk sac fry stage (21–23 d after hatching) in untreated normal and M74-affected groups were between 0.70–1.0 and 0.19–0.26 nmol/g, respectively. At the same sampling, the mean thiamine concentrations in groups in which eggs were waterhardened in thiamine at 500 or 2,000 mg/L were between 0.8 and 9.4 times higher than the concentrations in the untreated groups. A thiamine threshold limit interval of 0.34–0.47 nmol/g was estimated for the development of M74 in yolk sac fry.

Age-Related Mortality in a Wintering Population of Dunlin

The Auk ◽  
1984 ◽  
Vol 101 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Barbara E. Kus ◽  
Philip Ashman ◽  
Gary W. Page ◽  
Lynne E. Stenzel
Keyword(s):  
Age Differences ◽  
Mortality Rates ◽  
Considerable Evidence ◽  
Calidris Alpina ◽  
Age Related ◽  
Winter Population ◽  
Annual Mortality ◽  
Flocking Behavior ◽  
Related Mortality ◽  
Wintering Population

Abstract Despite considerable evidence that juvenile shorebirds experience significantly higher annual mortality rates than adults, identification and quantification of the sources of mortality have received little attention. We found that the proportion of juvenile Dunlins (Calidris alpina) in the kills of a Merlin (Falco columbarius) one winter at Bolinas Lagoon, California was greater than the proportion of juveniles in the lagoon's winter population. This is evidence that raptor predation may be one of the factors contributing to the age differences in annual mortality rates of shorebirds. We suggest that the greater vulnerability of juveniles to predation by the Merlin may be caused by age-related differences in Dunlin flocking behavior.

scholarly journals Early mortality and freshwater forage fish recruitment: nonnative alewife and native rainbow smelt interactions in Lake Champlain

2019 ◽  
Vol 76 (5) ◽  
pp. 806-814
Author(s):  
Paul W. Simonin ◽  
Lars G. Rudstam ◽  
Patrick J. Sullivan ◽  
Donna L. Parrish ◽  
Bernard Pientka
Keyword(s):  
Climate Change ◽  
Distribution Patterns ◽  
Mortality Rates ◽  
Early Mortality ◽  
Fish Distribution ◽  
Change Scenario ◽  
Lake Champlain ◽  
Species Introduction ◽  
Rainbow Smelt ◽  
Fish Recruitment

We studied the consequences of a nonnative species introduction and changes in temperature on early mortality and recruitment of native rainbow smelt (Osmerus mordax) and nonnative alewife (Alosa pseudoharengus) in Lake Champlain using a simulation model. Distribution patterns of adults and young-of-the-year (YOY) fish were predicted using a model based on observed distribution of different age groups as a function of temperature and light profiles simulated on a daily basis. Mortality rates averaged over the growing season were calculated as a function of fish densities and overlap between adults and YOY. Survival of YOY rainbow smelt and alewife depended on which predator was most abundant. Rainbow smelt YOY mortality rates are highest when rainbow smelt adults are abundant, and alewife YOY mortality rates are highest when alewife adults are abundant, potentially allowing coexistence. August and September mortality rates were higher in the climate change scenario because of increased overlap of adults and YOY of both species. These results indicate that accounting for spatiotemporal fish distribution patterns can be important when forecasting the interacting effects of climate change and aquatic invasive species on fish recruitment.

scholarly journals Mortality Associated with Idiopathic Pulmonary Fibrosis in Northeastern Italy, 2008–2020: A Multiple Cause of Death Analysis

2021 ◽  
Vol 18 (14) ◽  
pp. 7249
Author(s):  
Alessandro Marcon ◽  
Elena Schievano ◽  
Ugo Fedeli
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Cause Of Death ◽  
Age Groups ◽  
Mortality Rates ◽  
Annual Percent Change ◽  
Northeastern Italy ◽  
Mortality Ratio ◽  
The Impact ◽  
Related Mortality

Mortality from idiopathic pulmonary fibrosis (IPF) is increasing in most European countries, but there are no data for Italy. We analysed the registry data from a region in northeastern Italy to assess the trends in IPF-related mortality during 2008–2019, to compare results of underlying vs. multiple cause of death analyses, and to describe the impact of the COVID-19 epidemic in 2020. We identified IPF (ICD-10 code J84.1) among the causes of death registered in 557,932 certificates in the Veneto region. We assessed time trends in annual age-standardized mortality rates by gender and age (40–74, 75–84, and ≥85 years). IPF was the underlying cause of 1310 deaths in the 2251 certificates mentioning IPF. For all age groups combined, the age-standardized mortality rate from IPF identified as the underlying cause of death was close to the European median (males and females: 3.1 and 1.3 per 100,000/year, respectively). During 2008–2019, mortality rates increased in men aged ≥85 years (annual percent change of 6.5%, 95% CI: 2.0, 11.2%), but not among women or for the younger age groups. A 72% excess of IPF-related deaths was registered in March–April 2020 (mortality ratio 1.72, 95% CI: 1.29, 2.24). IPF mortality was increasing among older men in northeastern Italy. The burden of IPF was heavier than assessed by routine statistics, since less than two out of three IPF-related deaths were directly attributed to this condition. COVID-19 was accompanied by a remarkable increase in IPF-related mortality.

scholarly journals Quirky patterns in time-series of estimates of recruitment could be artefacts

2014 ◽  
Vol 72 (1) ◽  
pp. 111-116 ◽  
Author(s):  
M. Dickey-Collas ◽  
N. T. Hintzen ◽  
R. D. M. Nash ◽  
P-J. Schön ◽  
M. R. Payne
Keyword(s):  
Time Series ◽  
Stock Assessment ◽  
Meta Analysis ◽  
Reference Points ◽  
Fish Stocks ◽  
Stock Recruitment ◽  
Modelling Assumptions ◽  
Meta Analyses ◽  
Recruitment Model ◽  
Recruitment Time

Abstract The accessibility of databases of global or regional stock assessment outputs is leading to an increase in meta-analysis of the dynamics of fish stocks. In most of these analyses, each of the time-series is generally assumed to be directly comparable. However, the approach to stock assessment employed, and the associated modelling assumptions, can have an important influence on the characteristics of each time-series. We explore this idea by investigating recruitment time-series with three different recruitment parameterizations: a stock–recruitment model, a random-walk time-series model, and non-parametric “free” estimation of recruitment. We show that the recruitment time-series is sensitive to model assumptions and this can impact reference points in management, the perception of variability in recruitment and thus undermine meta-analyses. The assumption of the direct comparability of recruitment time-series in databases is therefore not consistent across or within species and stocks. Caution is therefore required as perhaps the characteristics of the time-series of stock dynamics may be determined by the model used to generate them, rather than underlying ecological phenomena. This is especially true when information about cohort abundance is noisy or lacking.

scholarly journals Mortality in Dementia from 1996 to 2015: A National Registry-Based Cohort Study

2021 ◽  
Vol 79 (1) ◽  
pp. 289-300
Author(s):  
Lærke Taudorf ◽  
Ane Nørgaard ◽  
Gunhild Waldemar ◽  
Thomas Munk Laursen
Keyword(s):  
Elderly People ◽  
Age Groups ◽  
Mortality Rates ◽  
Similar Rate ◽  
National Registry ◽  
Healthcare Data ◽  
Appropriate Care ◽  
People With Dementia ◽  
Rate Ratios ◽  
Annual Mortality

Background: It remains unclear whether the increased focus on improving healthcare and providing appropriate care for people with dementia has affected mortality. Objective: To assess survival and to conduct a time trend analysis of annual mortality rate ratios (MRR) of dementia based on healthcare data from an entire national population. Methods: We assessed survival and annual MRR in all residents of Denmark ≥65 years from 1996–2015 using longitudinal registry data on dementia status and demographics. For comparison, mortality and survival were calculated for acute ischemic heart disease (IHD) and cancer. Results: The population comprised 1,999,366 people (17,541,315 person years). There were 165,716 people (529,629 person years) registered with dementia, 131,321 of whom died. From 1996–2015, the age-adjusted MRR for dementia declined (women: 2.76 to 2.05; men: 3.10 to 1.99) at a similar rate to elderly people without dementia. The sex-, age-, and calendar-year-adjusted MRR was 2.91 (95%CI: 2.90–2.93) for people with dementia. MRR declined significantly more for acute IHD and cancer. In people with dementia, the five-year survival for most age-groups was at a similar level or lower as that for acute IHD and cancer. Conclusion: Although mortality rates declined over the 20-year period, MRR stayed higher for people with dementia, while the MRR gap, compared with elderly people without dementia, remained unchanged. For the comparison, during the same period, the MRR gap narrowed between people with and without acute IHD and cancer. Consequently, initiatives for improving health and decreasing mortality in dementia are still highly relevant.

scholarly journals Osteoarthritis, mobility-related comorbidities and mortality: an overview of meta-analyses

2020 ◽  
Vol 12 ◽  
pp. 1759720X2098121
Author(s):  
Gustavo Constantino de Campos ◽  
Raman Mundi ◽  
Craig Whittington ◽  
Marie-Josée Toutounji ◽  
Wilson Ngai ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Inclusion Criteria ◽  
Increased Risk ◽  
All Cause Mortality ◽  
Ischemic Attack ◽  
Meta Analyses ◽  
The Relationship ◽  
Related Mortality

Aims: The objective of this review was to examine the relationship between osteoarthritis (OA) and mobility-related comorbidities, specifically diabetes mellitus (DM) and cardiovascular disease (CVD). It also investigated the relationship between OA and mortality. Methods: An overview of meta-analyses was conducted by performing two targeted searches from inception to June 2020. The association between OA and (i) DM or CVD ( via PubMed and Embase); and (ii) mortality ( via PubMed) was investigated. Meta-analyses were selected if they included studies that examined adults with OA at any site and reported associations between OA and DM, CVD, or mortality. Evidence was synthesized qualitatively. Results: Six meta-analyses met inclusion criteria. One meta-analysis of 20 studies demonstrated a statistically significant association between OA and DM, with pooled odds ratio of 1.41 (95% confidence interval: 1.21, 1.65; n = 1,040,175 patients). One meta-analysis of 15 studies demonstrated significantly increased risk of CVD among OA patients, with a pooled risk ratio of 1.24 (1.12, 1.37, n = 358,944 patients). Stratified by type of CVD, OA was shown to be associated with increased heart failure (HF) and ischemic heart disease (IHD) and reduced transient ischemic attack (TIA). There was no association reported for stroke or myocardial infarction (MI). Three meta-analyses did not find a significant association between OA (any site) and all-cause mortality. However, OA was found to be significantly associated with cardiovascular-related death across two meta-analyses. Conclusion: The identified meta-analyses reported significantly increased risk of both DM and CVD (particularly, HF and IHD) among OA patients. It was not possible to confirm consistent directional or causal relationships. OA was found to be associated with increased mortality, but mostly in relation to CVD-related mortality, suggesting that further study is warranted in this area.

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