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The strength of species interactions may have profound effects on population dynamics. Empirical estimates of interaction strength are often based on the assumption that the interaction strengths are constant. Barents Sea (BS) cod and capelin are two fish populations for which such an interaction has been acknowledged and used, under the assumption of constant interaction strength, when studying their population dynamics. However, species interactions can often be nonlinear in marine ecosystems and might profoundly change our understanding of food chains. Analysing long-term time series data comprising a survey over 37 years in the Arcto-boreal BS, using a state-space modelling framework, we demonstrate that the effect of capelin on cod is not linear but shifts depending on capelin abundance: while capelin is beneficial for cod populations at high abundance; below the threshold, it becomes less important for cod. Our analysis therefore shows the importance of investigating nonlinearity in species interactions and may contribute to an improved understanding on species assemblages.
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Ecossistema , Osmeriformes , Animais , Cadeia Alimentar , Dinâmica Populacional , Comportamento PredatórioRESUMO
BACKGROUND: In Japan there is no consensus on how to efficiently measure quality indicators (QIs), defined as a standard of care, for acute ischemic stroke (AIS). Using information from a health insurance claims database and electronic medical records, we evaluated the feasibility and validity of measuring QIs for AIS patients who received intravenous recombinant tissue plasminogen activator (IV rt-PA) or endovascular therapy (EVT).MethodsâandâResults:AIS patients receiving rt-PA or EVT between 2013 and 2015 were identified. We selected 17 AIS QI measures for primary stroke centers (PSCs) and 8 for comprehensive stroke centers (CSCs). Defined QIs were calculated for each hospital and then averaged. In total, the data of 8,206 patients (rt-PA 83.7%, EVT 34.9%) from 172 hospitals were obtained. Median National Institute of Health Stroke Scale score at admission was 14, and 37.7% of the patients were functionally independent at discharge. All target QIs were successfully measured with fewer missing values, and the accuracy of preset data was about 90%. Adherence rates were low (<50%) in 5 QI measures among PSCs, including door-to-needle time ≤1 h, and in 1 QI measure among CSCs (door-to-brain and vascular imaging time ≤30 min). CONCLUSIONS: Measuring QIs for AIS by this novel approach was feasible and reliable in the provision of a national benchmark.
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Isquemia Encefálica , AVC Isquêmico , Isquemia Encefálica/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Humanos , AVC Isquêmico/tratamento farmacológico , Japão , Indicadores de Qualidade em Assistência à Saúde , Reperfusão , Terapia Trombolítica , Fatores de Tempo , Ativador de Plasminogênio Tecidual/uso terapêutico , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Climate change has profound ecological effects, yet our understanding of how trophic interactions among species are affected by climate change is still patchy. The sympatric Atlantic haddock and cod are co-occurring across the North Atlantic. They compete for food at younger stages and thereafter the former is preyed by the latter. Climate change might affect the interaction and coexistence of these two species. Particularly, the increase in sea temperature (ST) has been shown to affect distribution, population growth and trophic interactions in marine systems. We used 33-year long time series of haddock and cod abundances estimates from two data sources (acoustic and trawl survey) to analyse the dynamic effect of climate on the coexistence of these two sympatric species in the Arcto-Boreal Barents Sea. Using a Bayesian state-space threshold model, we demonstrated that long-term climate variation, as expressed by changes of ST, affected species demography through different influences on density-independent processes. The interaction between cod and haddock has shifted in the last two decades due to an increase in ST, altering the equilibrium abundances and the dynamics of the system. During warm years (ST over ca. 4°C), the increase in the cod abundance negatively affected haddock abundance while it did not during cold years. This change in interactions therefore changed the equilibrium population size with a higher population size during warm years. Our analyses show that long-term climate change in the Arcto-Boreal system can generate differences in the equilibrium conditions of species assemblages.
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Mudança Climática , Gadiformes , Animais , Teorema de Bayes , Ecossistema , Dinâmica PopulacionalRESUMO
While many in-laboratory ecotoxicological studies have shown the adverse impact of pollutants to the fitness of an individual, direct evidence from the field on the population dynamics of wildlife animals has been lacking. Here, we provide empirical support for a negative effect of pollution on Atlantic cod (Gadus morhua) population dynamics in coastal waters of Norway by combining unique time series of juvenile cod abundance, body size, environmental concentration of toxic contaminants and a spatially structured population dynamics model. The study shows that mercury concentration might have decreased the reproductive potential of cod in the region despite the general decline in the environmental concentration of mercury, cadmium and hexachlorobenzene since the implementation of national environmental laws. However, some cod populations appeared to be more resistant to mercury pollution than others, and the strength and shape of mercury effect on cod reproductive potential was fjord-specific. Additionally, cod growth rate changed at scales smaller than fjords with a gradient related to the exposure to the open ocean and offshore cod. These spatial differences in life-history traits emphasize the importance of local adaptation in shaping the dynamics of local wildlife populations. Finally, this study highlights the possibility to mitigate pollution effects on natural populations by reducing the overall pollution level, but also reveals that pollution reduction alone is not enough to rebuild local cod populations. Cod population recovery probably requires complementary efforts on fishing regulation and habitat restoration.
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Exposição Ambiental , Gadus morhua/fisiologia , Poluentes Químicos da Água/efeitos adversos , Animais , Estuários , Noruega , Dinâmica PopulacionalRESUMO
Species distribution models (SDMs) are important statistical tools for obtaining ecological insight into species-habitat relationships and providing advice for natural resource management. Many SDMs have been developed over the past decades, with a focus on space- and more recently, time-dependence. However, most of these studies have been on terrestrial species and applications to marine species have been limited. In this study, we used three large spatio-temporal data sources (habitat maps, survey-based fish density estimates, and fishery catch data) and a novel space-time model to study how the distribution of fishing may affect the seasonal dynamics of a commercially important fish species (Pacific Dover sole, Microstomus pacificus) off the west coast of the USA. Dover sole showed a large scale change in seasonal and annual distribution of biomass, and its distribution shifted from mid-depth zones to inshore or deeper waters during late summer/early fall. In many cases, the scale of fishery removal was small compared to these broader changes in biomass, suggesting that seasonal dynamics were primarily driven by movement and not by fishing. The increasing availability of appropriate data and space-time modeling software should facilitate extending this work to many other species, particularly those in marine ecosystems, and help tease apart the role of growth, natural mortality, recruitment, movement, and fishing on spatial patterns of species distribution in marine systems.
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Pesqueiros , Linguados/fisiologia , Distribuição Animal , Animais , Biomassa , Simulação por Computador , Modelos Biológicos , Oceano Pacífico , Dinâmica Populacional , Fatores de TempoRESUMO
Anadromous Chinook salmon populations vary in the period of river entry at the initiation of adult freshwater migration, facilitating optimal arrival at natal spawning. Run timing is a polygenic trait that shows evidence of rapid parallel evolution in some lineages, signifying a key role for this phenotype in the ecological divergence between populations. Studying the genetic basis of local adaptation in quantitative traits is often impractical in wild populations. Therefore, we used a novel approach, Random Forest, to detect markers linked to run timing across 14 populations from contrasting environments in the Columbia River and Puget Sound, USA. The approach permits detection of loci of small effect on the phenotype. Divergence between populations at these loci was then examined using both principle component analysis and FST outlier analyses, to determine whether shared genetic changes resulted in similar phenotypes across different lineages. Sequencing of 9107 RAD markers in 414 individuals identified 33 predictor loci explaining 79.2% of trait variance. Discriminant analysis of principal components of the predictors revealed both shared and unique evolutionary pathways in the trait across different lineages, characterized by minor allele frequency changes. However, genome mapping of predictor loci also identified positional overlap with two genomic outlier regions, consistent with selection on loci of large effect. Therefore, the results suggest selective sweeps on few loci and minor changes in loci that were detected by this study. Use of a polygenic framework has provided initial insight into how divergence in a trait has occurred in the wild.
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Migração Animal , Evolução Biológica , Genética Populacional , Salmão/genética , Adaptação Fisiológica/genética , Algoritmos , Animais , Inteligência Artificial , Mapeamento Cromossômico , Frequência do Gene , Fenótipo , Reprodução/genética , WashingtonRESUMO
Identifying spatiotemporal hotspots is important for understanding basic ecological processes, but is particularly important for species at risk. A number of terrestrial and aquatic species are indirectly affected by anthropogenic impacts, simply because they tend to be associated with species that are targeted for removals. Using newly developed statistical models that allow for the inclusion of time-varying spatial effects, we examine how the co-occurrence of a targeted and nontargeted species can be modeled as a function of environmental covariates (temperature, depth) and interannual variability. The nontarget species in our case study (eulachon) is listed under the U.S. Endangered Species Act, and is encountered by fisheries off the U.S. West Coast that target pink shrimp. Results from our spatiotemporal model indicated that eulachon bycatch risk decreases with depth and has a convex relationship with sea surface temperature. Additionally, we found that over the 2007-2012 period, there was support for an increase in eulachon density from both a fishery data set (+40%) and a fishery-independent data set (+55%). Eulachon bycatch has increased in recent years, but the agreement between these two data sets implies that increases in bycatch are not due to an increase in incidental targeting of eulachon by fishing vessels, but because of an increasing population size of eulachon. Based on our results, the application of spatiotemporal models to species that are of conservation concern appears promising in identifying the spatial distribution of environmental and anthropogenic risks to the population.
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Distribuição Animal , Modelos Biológicos , Pandalidae/fisiologia , Animais , Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental , Pesqueiros , Peixes/fisiologia , Especificidade da EspécieRESUMO
State-space estimation methods are increasingly used in ecology to estimate productivity and abundance of natural populations while accounting for variability in both population dynamics and measurement processes. However, functional forms for population dynamics and density dependence often will not match the true biological process, and this may degrade the performance of state-space methods. We therefore developed a Bayesian semiparametric state-space model, which uses a Gaussian process (GP) to approximate the population growth function. This offers two benefits for population modeling. First, it allows data to update a specified "prior" on the population growth function, while reverting to this prior when data are uninformative. Second, it allows variability in population dynamics to be decomposed into random errors around the population growth function ("process error") and errors due to the mismatch between the specified prior and estimated growth function ("model error"). We used simulation modeling to illustrate the utility of GP methods in state-space population dynamics models. Results confirmed that the GP model performs similarly to a conventional state-space model when either (1) the prior matches the true process or (2) data are relatively uninformative. However, GP methods improve estimates of the population growth function when the function is misspecified. Results also demonstrated that the estimated magnitude of "model error" can be used to distinguish cases of model misspecification. We conclude with a discussion of the prospects for GP methods in other state-space models, including age and length-structured, meta-analytic, and individual-movement models.
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Teorema de Bayes , Simulação por Computador , Modelos Biológicos , Modelos Estatísticos , Dinâmica PopulacionalRESUMO
Climate change has a profound impact on species distribution and abundance globally, as well as local diversity, which affects ecosystem functioning. In particular, changes in population distribution and abundance may lead to changes in trophic interactions. Although species can often shift their spatial distribution when suitable habitats are available, it has been suggested that predator presence can be a constraint on climate-related distribution shifts. We test this using two well-studied and data-rich marine environments. Focusing on a pair of sympatric fishes, Atlantic haddock Melanogrammus aeglefinus and cod Gadus morhua, we study the effect of the presence and abundance of the latter on the former distribution. We found that the distribution of cod and increased abundance may limit the expansion of haddock to new areas and could consequently buffer ecosystem changes due to climate change. Though marine species may track the rate and direction of climate shifts, our results demonstrate that the presence of predators may limit their expansion to thermally suitable habitats. By integrating climatic and ecological data at scales that can resolve predator-prey relationships, this analysis demonstrates the usefulness of considering trophic interactions to gain a more comprehensive understanding and to mitigate the effects of climate change on species distributions.
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Ecossistema , Peixes , Animais , Comportamento Predatório , Mudança ClimáticaRESUMO
Fishery-dependent data are frequently used to inform management decisions. However, inferences about stock development based on commercial data such as Catch-Per-Unit-Effort (CPUE) can be severely biased due to a phenomenon known as technological creep, where fishing technology improves over time. Here we show how trap improvement over nine decades has driven technological creep in a European lobster (Homarus gammarus) fishery. We combined fishing data, experimental fishing with contemporary and older trap types, and information on depletion effects during fishing seasons. The resulting standardized CPUE time series indicates a 92% decline in lobster abundance between 1928 and 2019 compared to 70% if technological creep is not corrected for. Differences are most pronounced within the last 40 years when the most substantial shift in gear technology occurred: an uncorrected CPUE index suggests an 8% increase in lobster abundance during this period, while the corrected CPUE index declined by 57%. We conclude that technological creep has masked a continuous stock decline, particularly in recent decades and largely driven by the shift from one- to two-chambered traps, as well as the ability of newer trap designs to capture larger lobsters. Our study confirms the importance of adequate standardization, including technological development, when using fishery dependent CPUE for monitoring and management of data-limited fisheries.
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Pesqueiros , Nephropidae , Tecnologia , AnimaisRESUMO
BACKGROUND: Long-term outcomes after surgical treatment of arachnoid cysts (ACs) have not been reported adequately. Impaired visual acuity is not a common symptom of shunt dependency syndrome due to cyst-peritoneal (CP) shunt malfunction for ACs. We report a case of CP shunt malfunction, who presented only impaired visual acuity as a symptom, long after the initial surgical treatment. CASE DESCRIPTION: A 16-year-old boy was surgically treated for the left frontal AC with CP shunting at 2 years of age. Extension of the peritoneal shunt catheter was performed at 15 years of age. A year later, he started experiencing impairment of visual acuity without headaches, which worsened to bilateral light perception. The presence of bilateral optic atrophy was confirmed. The AC in the left frontal lobe had enlarged very slightly, with shortening of the intracystic catheter, and the cerebrospinal fluid pressure was elevated to 30 cmH2O. He was treated with lumboperitoneal shunting. The visual acuity showed limited improvement. CONCLUSION: The possibility of CP shunt malfunction and shunt dependency syndrome should be considered, even if the patient presented only impaired visual acuity and no significant changes in the size of the ACs are observed.
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Background: Angiolipomas are benign mesenchymal tumors comprising mature adipocytes and abnormal blood vessels, commonly found in the subcutaneous tissue of the trunk and rarely in the skull. Furthermore, sporadic cases of angiolipoma with arteriovenous fistula (AVF) have been reported. Case Description: We reported the case of a 72-year-old woman who presented with head swelling, seizures, and cognitive dysfunction. Computed tomography and magnetic resonance imaging revealed a right frontal bone tumor exceeding a sagittal suture of up to 10.7 cm. Angiography revealed AVF and varices formation. Endovascular embolization was performed to treat the AVF and reduce blood loss during surgical resection. Two days after the embolization, a craniotomy was performed; however, uncontrollable bleeding was observed at the time of tumor resection. Postoperatively, the patient was symptom-free and has been stable for 2 years without recurrence. Conclusion: Despite careful preoperative evaluation and treatment planning, the patient in this case report was difficult to treat. Such cases require adequate preparation.
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Coastal ecosystem health is of vital importance to human well-being. Field investigations of major pollutants along the whole coast of China were carried out to explore associations between coastal development activities and pollutant inputs. Measurements of target pollutants such as PFAAs and PAHs uncovered notable levels in small estuary rivers. The Yangtze River was identified to deliver the highest loads of these pollutants to the seas as a divide for the spatial distribution of pollutant compositions. Soil concentrations of the volatile and semi-volatile pollutants showed a cold-trapping effect in pace with increasing latitudinal gradient. The coastal ecosystem is facing high ecological risks from metal pollution, especially copper (Cu) and zinc (Zn), while priority pollutants of high risks vary for different kinds of protected species, and the ecological risks were influenced by both climate and physicochemical properties of environmental matrices, which should be emphasized to protect and restore coastal ecosystem functioning.
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Poluentes Ambientais , Poluentes Químicos da Água , China , Ecossistema , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Oceanos e Mares , Medição de Risco , Rios , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Presenteeism is the loss of work productivity of workers owing to physical and mental problems, and its socioeconomic effects are greater than those of absenteeism. Presenteeism is caused by psychological and physical dysfunctions. On the other hand, the regularity of mealtimes is an important factor associated with physical and mental health conditions. We hence assessed the association among the irregularity of mealtimes, presenteeism, psychological and physical stress responses, and sleep disturbance in office workers in companies. METHODS: From May to December 2017, the data of 2905 participants who had given their consent to use their information for academic purposes, and answered a questionnaire about the survey and their lifestyle were collected. Path analysis was performed to analyze the association between the irregularity of mealtimes, psychosomatic symptoms (Brief Job Stress Questionnaire), sleep disturbance (Pittsburgh Sleep Questionnaire), and presenteeism (Work Limitations Questionnaire). RESULTS: The direct effect of the irregularity of mealtimes on presenteeism was significant but weak. However, the irregularity of mealtimes had a strong effect on presenteeism indirectly through psychological and physical stress responses and sleep disturbance. CONCLUSION: Psychological and physical stress responses and sleep disturbance were identified as mediating factors of the effects of irregularity of mealtimes on presenteeism.
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[This corrects the article DOI: 10.3389/fpsyt.2020.00776.].
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BACKGROUND: Occupational mental health, work environment, sleep health, presenteeism, and loss of work productivity caused by health problems are all public health concerns. Although sleep affects mental health and presenteeism, the associations between sleep disturbance, job stressors, stress responses, and presenteeism have remained unclear. We hypothesized that job stressors affect the presenteeism of office workers through sleep disturbance and analyzed the association among these factors. SUBJECTS AND METHODS: In 2017, a cross-sectional survey of adult office workers was performed. A total of 2899 subjects who provided written consent were included in the analysis. The survey collected demographic information, as well as the Work Limitation Questionnaire (WLQ), Pittsburgh Sleep Quality Index (PSQI), and Brief Job Stress Questionnaire (BJSQ). Associations between each of the variables were analyzed by path analysis (covariance structure analysis). This study was approved by the Ethics Committee of Tokyo Medical University. RESULTS: The path analysis demonstrated that job stressors, psychological and physical stress response (PPSR) in the BJSQ, and sleep disturbance in the PSQI had direct effects on presenteeism in the WLQ. Both job stressors and social support in the BJSQ indirectly affected presenteeism through effects on sleep disturbance and PPSR. Sleep disturbance indirectly affected presenteeism via PPSR. This model accounted for the variation of presenteeism (R 2 = 0.322). CONCLUSION: In the workplace, job stressors and low social support increase presenteeism through psychological and physical stress responses, as well as sleep disturbance. Evaluating and resolving work problems and sleep disturbance would hence be beneficial from the aspects of public health and socioeconomics.
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BACKGROUND: The complex interaction between parenting styles, job stressors, and the stress response has not been clarified to date. We hypothesized that neuroticism acts as a mediator in the effects of parenting quality on perceived job stressors and the psychological and physical stress response (PPSR), and tested this hypothesis using covariance structure analysis. SUBJECTS AND METHODS: We conducted research between April 2017 and April 2018 on 597 adult from the community, and 69 subjects were excluded owing to missing data or nonworkers. Finally, a total of 528 participants were analyzed using the following self-administered questionnaires: the Parental Bonding Instrument, the shortened Eysenck Personality Questionnaire-Revised, and the Brief Job Stress Questionnaire (BJSQ). The data were analyzed by single regression analyses and covariance structure analyses. Job stress was assessed by the BJSQ and 2 subscales, ie, perceived job stressors and the PPSR. This study was approved by the Ethics Committee of Tokyo Medical University. RESULTS: On covariance structure analysis, high parental overprotection was associated with high neuroticism and high PPSR directly, but had no significant effect on perceived job stressors. High parental overprotection was associated with high-perceived job stressors and the high PPSR indirectly through enhanced neuroticism. High parental overprotection was also associated with the high PPSR indirectly through 2 combined paths of neuroticism and perceived job stressors. This model accounted for 40% of the variability of the PPSR. On the other hand, parental care had opposite effects to parental overprotection, and this model of parental care accounted for 39% of the variability of PPSR. The model fits of the 2 models were good. CONCLUSION: Our results suggest that the quality of parenting in childhood is associated with perceived job stressors and the PPSR indirectly through neuroticism.
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BACKGROUND: Chronotype, which is a person's circadian characteristics throughout a day, greatly influences a person's lifestyle, health, and sleep pattern; however, the association between job stress and chronotype remains unknown to date. Therefore, in this study, we analyzed the effects of chronotype on the job stress response, and the mediating effects of sleep disturbance using path analysis. METHODS: A cross-sectional survey was conducted on 535 adult volunteers (239 men and 296 women; average age, 41.2 ± 11.9 years) from the community. Participants were evaluated using the Diurnal Type Scale for chronotype, Pittsburg Sleep Quality Index for sleep disturbance, Brief Job Stress Questionnaire for job stressors, and the psychological and physical stress response (PPSR). To investigate the association between chronotype, sleep disturbance, perceived job stressors, and PPSR, a covariance structure analysis was performed. RESULTS: The eveningness chronotype had a significant weak direct effect on sleep disturbance, perceived job stressors, and PPSR, and had a significant indirect effect through sleep disturbance. The perceived job stressors indirectly increased PPSR through sleep disturbance. Sleep disturbance mediated the effects of the eveningness chronotype and perceived job stressors on PPSR. This model accounted for 37.3% of the variability in PPSR of adult workers. CONCLUSION: Chronotype affected PPSR through sleep disturbance. Therefore, improving the sleep disturbance of workers with the eveningness chronotype may reduce their stress response.
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BACKGROUND: Stress responses induced by job stressors are modified by individual factors. Perceived parental bonding and resilience would play important roles as such individual factors. In this study, we analyzed the mediating roles of resilience on parenting, job stressors, and stress responses among adult workers from the community. METHODS: A total of 528 workers participated in this study after providing written consent, and completed questionnaires on demographic data, as well as Parental Bonding Instrument, Connor-Davidson Resilience Scale, and Brief Job Stress Questionnaire. Associations between perceived parental bonding, resilience, perceived job stressors, and the psychological and physical stress response (PPSR) were analyzed using structural equation modeling. RESULTS: Structural equation modeling with covariance structure analysis showed that parental overprotection reduced resilience and increased perceived job stressors and PPSR. Resilience and perceived job stressors and their combination mediated the effect of parental overprotection on PPSR. Resilience mediated the effect of parental overprotection on perceived job stressors. Perceived job stressors mediated the effect of resilience on PPSR. Parental care had opposite effects to parental overprotection, but the difference was small. CONCLUSION: In this study, we showed that perceived parental bonding affects resilience, and that both factors affect the stress response and perceived job stressors. These findings suggest that parental bonding and resilience are major individual factors affecting work stress, and should be noted when considering industrial hygiene measures for individual workers.
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Conservation efforts and management decisions on the living environment of our planet often rely on the results from statistical models. Yet, these models are imperfect and quantification of risk associated with the estimate of management-relevant quantities becomes crucial in providing robust advice. Here we demonstrate that estimates of risk themselves could be substantially biased but by combining data fitting with an extensive simulation-estimation procedure, one can back-calculate the correct values. We apply the method to 627 time series of population abundance across four taxa using the Gompertz state-space model as an example. We find that the risk of large bias in population status estimate increases with the species' growth rate, population variability, weaker density dependence, and shorter time series, across taxa. We urge scientists dealing with conservation and management to adopt a similar approach to ensure a more accurate estimate of risk measures and contribute towards a precautionary approach to management.