Catastrophic Mortality Research Articles

Major abdominal surgery in Jehovah's Witnesses.

Introduction Patients who are Jehovah's Witnesses pose difficult ethical and moral dilemmas for surgeons because of their refusal to receive blood and blood products. This article outlines the personal experiences of six Jehovah's Witnesses who underwent major abdominal surgery at a single institution and also summarises the literature on the perioperative care of these patients. Methods The patients recorded their thoughts and the dilemmas they faced during their surgical journey. We also reviewed the recent literature on the ethical principles involved in treating such patients and strategies recommended to make surgery safer. Results All patients were supported in their decision making by the clinical team and the Hospital Liaison Committee for Jehovah's Witnesses. The patients recognised the ethical and moral difficulties experienced by clinicians in this setting. However, they described taking strength from their belief in Jehovah. A multitude of techniques are available to minimise the risk associated with major surgery in Jehovah's Witness patients, many of which have been adopted to minimise unnecessary use of blood products in general. Nevertheless, the risks of catastrophic haemorrhage and consequent mortality remain an unresolved issue for the treating team. Conclusions Respect for a patient's autonomy in this setting is the overriding ethical principle, with detailed discussion forming an important part of the preparation of a Jehovah's Witness for major abdominal surgery. Clinicians must be diligent in the documentation of the patient's wishes to ensure all members of the team can abide by these.

The Risk of a Mortality Catastrophe

We develop a continuous-time model for analyzing and valuing catastrophe mortality contingent claims based on stochastic modeling of the force of mortality. We derive parameter estimates from a 105-year time series of U.S. population mortality data using a simulated maximum likelihood approach based on a particle filter. Relying on the resulting parameters, we calculate loss profiles for a representative catastrophe mortality transaction and compare them to the “official” loss profiles that are provided by the issuers to investors and rating agencies. We find that although the loss profiles are subject to great uncertainties, the official figures fall significantly below the corresponding risk statistics based on our model. In particular, we find that the annualized incidence probability of a mortality catastrophe, defined as a 15% increase in aggregated mortality probabilities, is about 1.4%—compared to about 0.1% according to the official loss profiles.

Temporal consistency in background mortality of four dominant coral taxa along Australia’s Great Barrier Reef

Studies on the population and community dynamics of scleractinian corals typically focus on catastrophic mortality associated with acute disturbances (e.g., coral bleaching and outbreaks of crown-of-thorns starfish), though corals are subject to high levels of background mortality and injuries caused by routine and chronic processes. This study quantified prevalence (proportion of colonies with injuries) and severity (areal extent of injuries on individual colonies) of background mortality and injuries for four common coral taxa (massive Porites, encrusting Montipora, Acropora hyacinthus and branching Pocillopora) on the Great Barrier Reef, Australia. Sampling was conducted over three consecutive years during which there were no major acute disturbances. A total of 2276 adult colonies were surveyed across 27 sites, within nine reefs and three distinct latitudinal sectors. The prevalence of injuries was very high (>83%) across all four taxa, but highest for Porites (91%) and Montipora (85%). For these taxa (Montipora and Pocillopora), there was also significant temporal and spatial variation in prevalence of partial mortality. The severity of injuries ranged from 3% to more than 80% and varied among coral taxa, but was fairly constant spatially and temporally. This shows that some injuries have considerable longevity and that corals may invest relatively little in regenerating tissue over sites of previous injuries. Inter-colony variation in the severity of injury also had no apparent effect on the realized growth of individual colonies, suggesting that energy diverted to regeneration has a limited bearing on overall energetic allocation, or impacts on other life-history processes (e.g., reproduction) rather than growth. Establishing background levels of injury and regeneration is important for understanding energy investment and life-history consequences for reef-building corals as well as for predicting susceptibility to, and capacity to recover from, acute disturbances.

Frailty and famine: Patterns of mortality and physiological stress among victims of famine in medieval London

Famine can be defined as a shortage of foodstuffs that instigates widespread excess mortality due to starvation, infectious disease, and social disruption. Like other causes of catastrophic mortality, famine has the potential to be selective. This study examines how famines in medieval London were selective with respect to previous stress, age, and sex. This study compares famine burials to nonfamine (attritional) burials from the St Mary Spital cemetery, London (c. 1120-1540 AD). We evaluate the associations between age, sex, and skeletal stress indicators [cribra orbitalia, linear enamel hypoplasia (LEH), and periosteal lesions] using hierarchical log-linear analysis. Additionally, sex is modeled as a covariate affecting the Gompertz hazard of mortality. Significant associations exist between famine burials and LEH and between attritional burials and periosteal lesions, independent of age or sex. Sex did not significantly affect risk of mortality in the 12th-13th centuries. However, males interred in attritional burials c. 1400-1539 AD faced a lower risk of mortality compared to females. The LEH results suggest that early exposure to stressors increased frailty in the context of famine. The periosteal lesion results suggest that individuals were more likely to survive stressors and thus form these lesions under nonfamine conditions. Hazard analysis suggests that a cultural or biological transformation during this period affected sex differences in mortality. Possible causes include the selective mortality during the Black Death, which might have influenced risks of mortality among survivors, or unequal distribution of improvements in standards of living after the epidemic. Am J Phys Anthropol 160:272-283, 2016. © 2016 Wiley Periodicals, Inc.

Role of Cyclonic Storm as Natural Disaster and other Factors on Vulture Mortality in India

Post mortem analyses in vultures across India and its neighboring countries traced diclofenac and its derivative compounds in their carcasses. Therefore, it is inferred that biomagnification of diclofenac from the consumed infected domestic animal carcasses contributes mortality by causing renal failure and hepatic damages in vultures. However, reports also indicate that both extrinsic environmental and intrinsic cellular causes might also be contributing factors. It offers a debate to confirm whether only diclofenac is the primary cause of vulture mortality versus their susceptibility to microbial pathogens, diseases or physiological conditions, such as oxidative stress due to diclofenac biomagnification. It is observed that natural disasters such as heavy cyclonic storm which affect arboreal life may be one of the major causes of the death of vultures in some parts of India. Therefore, extrinsic insults such as heavy cyclonic storms are believed to be also contributing factor to affect arboreal life including vultures in some other parts of the world. A perspective is made on the above facts as a cause of catastrophic mortality of vultures in India.

Catastrophe modelling: deriving the 1-in-200 year mortality shock for a South African insurer’s capital requirements under Solvency Assessment and Management

This paper investigates catastrophe risk for South African life insurers by considering the additional deaths that could arise from a 1-in-200 year mortality shock. Existing South African academic research on catastrophic risk has mostly focused on property losses and the resulting impact on property insurance companies. Life catastrophe risks have not been extensively modelled in a South African context. Local research would be beneficial in terms of quantifying these catastrophic risks for South African life insurers, and would assist firms when assessing their own catastrophe mortality solvency requirements under the new Solvency Assessment and Management (SAM) regime by providing a summary of data relating to various past catastrophes. In this paper we model a wide range of catastrophes to assess such mortality risk faced by life insurance companies in South Africa. An extensive exercise was undertaken to obtain data for a wide range of catastrophes and these data were used to derive severity and frequency distributions for each type of catastrophe. Data relating to global events were used to supplement South African data where local data were sparse. Data sources included official government statistics, industry reports and historical news reports. Since, by nature, catastrophic events are rare, little data are available for certain types of catastrophe. This means there is a large degree of uncertainty underlying some of the estimates. Simulation techniques were used to derive estimated distributions for the potential number of deaths for particular catastrophic events. The calculated overall shock for the national population was 2.6 deaths per thousand, which was lower than the SAM Pillar 1 shock of 3.2 deaths per thousand for the same population. It has been found that a worldwide pandemic is by far the main risk in terms of number of deaths in a catastrophe and, given that this is the most significant component of catastrophe risk, prior research on this risk in an South African context is summarised and revisited.

Microbialites in the shallow-water marine environments of the Holy Cross Mountains (Poland) in the aftermath of the Frasnian–Famennian biotic crisis

Microbial carbonates, consisting of abundant girvanellid oncoids, are described from cephalopod-crinoid and crinoid-brachiopod coquinas (rudstones) occurring in the lowermost Famennian of the Holy Cross Mountains, Poland. A Girvanella-bearing horizon (consist with numerous girvanellid oncoids) has been recognised at the Psie Górki section, and represents the northern slope succession of the drowned Dyminy Reef. This occurrence of microbialites in the aftermath of the Frasnian-Famennian event is interpreted as the result of opportunistic cyanobacteria blooms, which, as ‘disaster forms’, colonised empty shallow-water ecological niches during the survival phase following the Frasnian metazoan reef collapse, due to collapsed activity of epifaunal, grazing, and/or burrowing animals. The anachronistic lithofacies at Psie Górki is linked with catastrophic mass mortality of the cephalopod and crinoid-brachiopod communities during the heavy storm events. This mass occurrence of girvanellid oncoids, along with Frutexites-like microbial shrubs and, at least partly, common micritisation of some skeletal grains, records an overall increase in microbial activity in eutrophic normal marine environments. Microbial communities in the Holy Cross Mountains are not very diverse, being mainly represented by girvanellid oncoids, and stand in contrast to the very rich microbial communities known from the Guilin area (China), Canning Basin (Australia) and the Timan–northern Ural area (Russia). The association from Poland is similar to more diverse microbial communities represented by oncoids, trombolites and stromatolites, well known from the Canadian Alberta basin.

A DCC-GARCH multi-population mortality model and its applications to pricing catastrophic mortality bonds

This paper considers the pricing problem of catastrophic mortality bonds, which have been traded among financial institutions since about 10 years ago. We first use a DCC-GARCH model to capture the evolution of the aggregate mortality rates for five developed countries jointly. We then utilize the estimated model to price an illustrative catastrophic mortality bond, which, similar to most of the existing catastrophic mortality bonds, is linked to the mortality of multiple populations. We also study the impact of various features of the DCC-GARCH model on the pricing results.

Catastrophic health expenditure and 12-month mortality associated with cancer in Southeast Asia: results from a longitudinal study in eight countries.

BackgroundOne of the biggest obstacles to developing policies in cancer care in Southeast Asia is lack of reliable data on disease burden and economic consequences. In 2012, we instigated a study of new cancer patients in the Association of Southeast Asian Nations (ASEAN) region – the Asean CosTs In ONcology (ACTION) study – to assess the economic impact of cancer.MethodsThe ACTION study is a prospective longitudinal study of 9,513 consecutively recruited adult patients with an initial diagnosis of cancer. Twelve months after diagnosis, we recorded death and household financial catastrophe (out-of-pocket medical costs exceeding 30 % of annual household income). We assessed the effect on these two outcomes of a range of socio-demographic, clinical, and economic predictors using a multinomial regression model.ResultsThe mean age of participants was 52 years; 64 % were women. A year after diagnosis, 29 % had died, 48 % experienced financial catastrophe, and just 23 % were alive with no financial catastrophe. The risk of dying from cancer and facing catastrophic payments was associated with clinical variables, such as a more advanced disease stage at diagnosis, and socioeconomic status pre-diagnosis. Participants in the low income category within each country had significantly higher odds of financial catastrophe (odds ratio, 5.86; 95 % confidence interval, 4.76–7.23) and death (5.52; 4.34–7.02) than participants with high income. Those without insurance were also more likely to experience financial catastrophe (1.27; 1.05–1.52) and die (1.51; 1.21–1.88) than participants with insurance.ConclusionsA cancer diagnosis in Southeast Asia is potentially disastrous, with over 75 % of patients experiencing death or financial catastrophe within one year. This study adds compelling evidence to the argument for policies that improve access to care and provide adequate financial protection from the costs of illness.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-015-0433-1) contains supplementary material, which is available to authorized users.

Geographically conserved rates of background mortality among common reef-building corals in Lhaviyani Atoll, Maldives, versus northern Great Barrier Reef, Australia

Even in the absence of major disturbances (e.g., cyclones and bleaching), corals are consistently subject to high levels of background mortality, which undermines individual fitness and resilience of coral colonies. Most studies of coral mortality however only focus on catastrophic mortality associated with major acute disturbance events, neglecting to consider background levels of chronic mortality that have a significant influence on population structure and turnover. If, for example, there are geographic differences in the prevalence of injuries and rates of background mortality, coral communities may vary in their susceptibility to acute large-scale disturbances and environmental change. This study quantified the prevalence and severity of partial mortality for four dominant and widespread coral taxa (massive Porites, encrusting Montipora, Acropora hyacinthus, and branching Pocillopora) at Lhaviyani Atoll, Maldives, and on the northern Great Barrier Reef, Australia. The prevalence and severity of sublethal injuries varied greatly among taxa, but was generally similar between locations; on the Great Barrier Reef, 99.4 % Porites colonies, 66 % of A. hyacinthus, and 64 % of Pocillopora had conspicuous injuries, compared to 92.4 % of Porites, 47.5 % of A. hyacinthus, and 44 % of Pocillopora colonies in Lhaviyani Atoll. These results suggest that background rates of mortality and injury, and associated resilience of coral populations and communities to large-scale disturbances, are conserved at large geographic scales, though adjacent colonies can have markedly different injury regimes, likely to lead to strong intraspecific variation in colony fitness and resilience.

Population resilience to catastrophic mortality events during early life stages.

Catastrophic mortality events that drastically reduce the abundance of a population or a particular life stage can have long-term ecological and economic effects, and are of great concern in species conservation and management. Severe die-offs may be caused by natural catastrophes such as disease outbreaks and extreme climates, or human-caused disturbances such as toxic spills. Forecasting potential impacts of such disturbances is difficult and highly uncertain due to unknown future conditions, including population status and environmental conditions at the time of impact. Here, we present a framework for quantifying the range of potential, population-level effects of catastrophic events based on a hindcasting approach. A dynamic population model with Bayesian parameter estimation is used to simulate the impact of severe (50-99%) mortality events during the early life stages of Northeast Arctic cod (Gadus morhua), an abundant marine fish population of high economic value. We quantify the impact of such die-offs in terms of subsequent changes in population biomass and harvest through direct comparison of simulated and historical trends, and estimate the duration of the impact as a measure of population resilience. Our results demonstrate strong resilience to catastrophic events that affect early life stages owing to density dependence in survival and a broad population age structure. Yet, while population recovery is. relatively fast, losses in harvest and economic value can be substantial. Future research efforts should focus on long-term and indirect effects via food web interactions in order to better understand the ecological and economic ramifications of catastrophic mortality events.

The age pattern of transitory mortality jumps and its impact on the pricing of catastrophic mortality bonds

To value catastrophic mortality bonds, a number of stochastic mortality models with transitory jump effects have been proposed. Rather than modeling the age pattern of jump effects explicitly, most of the existing models assume that the distributions of jump effects and general mortality improvements across ages are identical. Nevertheless, this assumption does not seem to be in line with what we observe from historical data. In this paper, we address this problem by introducing a Lee–Carter variant that captures the age pattern of mortality jumps by a distinct collection of parameters. The model variant is then further generalized to permit the age pattern of jump effects to vary randomly. We illustrate the two proposed models with mortality data from the United States and English and Welsh populations, and use them to value hypothetical mortality bonds with similar specifications to the Atlas IX Capital Class B note that was launched in 2013. It is found that the features we consider have a significant impact on the estimated prices.

A Novel Approach for Prediction of Bulging in the type A Dissected Aorta Using MIMICS Tool

Aortic Dissection (AD), an erratic endangering disease, causes avulsing of intimal and medial layer of aorta and creates a false lumen. The blood passes through the false lumen protrudes aorta leads to intimal flap causes morbidity and mortality. In this catastrophe mortality rate increases as high as 1% per hour [14]. If untreated 33% will die within 24 hours, 50% in 48 hours, 75% in two weeks and 90% in one month. The surgical procedures involves replacement of Type A dissected aorta by implant and Type B by stent graft. After regimen 29% of death occurs due to rupture and 17-25% incidence of re-dissection formation. In this venture, 3D model of Stanford type A dissected aorta is segmented from CT images (DICOM) using MIMICS (Materialize Interactive Medical Image Control System) tool. Measurement of number of entries and re-entries, area of lumen and diameter are done in 3D segmented aorta in MIMICS. The detailed description of blood transport within the true and false lumen is analysed by centreline calculation and also prediction of bulging of aorta under certain blood pressure and loading distribution such as wall shear stress and strain has also been investigated by ANSYS WORKBENCH. The patient specific implant was created using composite material to replace the dissected aorta will greatly reduce the mortality rate of humans after surgery.

Implementation of a portable device for real-time ECG signal analysis

BackgroundCardiac disease is one of the main causes of catastrophic mortality. Therefore, detecting the symptoms of cardiac disease as early as possible is important for increasing the patient’s survival. In this study, a compact and effective architecture for detecting atrial fibrillation (AFib) and myocardial ischemia is proposed. We developed a portable device using this architecture, which allows real-time electrocardiogram (ECG) signal acquisition and analysis for cardiac diseases.MethodsA noisy ECG signal was preprocessed by an analog front-end consisting of analog filters and amplifiers before it was converted into digital data. The analog front-end was minimized to reduce the size of the device and power consumption by implementing some of its functions with digital filters realized in software. With the ECG data, we detected QRS complexes based on wavelet analysis and feature extraction for morphological shape and regularity using an ARM processor. A classifier for cardiac disease was constructed based on features extracted from a training dataset using support vector machines. The classifier then categorized the ECG data into normal beats, AFib, and myocardial ischemia.ResultsA portable ECG device was implemented, and successfully acquired and processed ECG signals. The performance of this device was also verified by comparing the processed ECG data with high-quality ECG data from a public cardiac database. Because of reduced computational complexity, the ARM processor was able to process up to a thousand samples per second, and this allowed real-time acquisition and diagnosis of heart disease. Experimental results for detection of heart disease showed that the device classified AFib and ischemia with a sensitivity of 95.1% and a specificity of 95.9%.ConclusionsCurrent home care and telemedicine systems have a separate device and diagnostic service system, which results in additional time and cost. Our proposed portable ECG device provides captured ECG data and suspected waveform to identify sporadic and chronic events of heart diseases. This device has been built and evaluated for high quality of signals, low computational complexity, and accurate detection.

A massacred village community? Agent-based modelling sheds new light on the demography of the Neolithic mass grave of Talheim.

The virtual experiments presented below reveal the counterintuitive archaeological demography of the Neolithic mass grave of Talheim and underline the importance of distinguishing between the demographic structures of living and dead populations, as well as between attritional and catastrophic mortality patterns. We utilise a new agent-based modelling approach called Population & Cemetery Simulator based on the NetLogo programming language and the Behaviour Composer of the modelling4all project, which allows us to extrapolate from dead to living populations and vice versa. Contrary to received opinion, we argue that the population of the Neolithic mass grave holds specific demographic information only, as it represents a pure catastrophic mortality pattern, i.e. a living population at a single point in time rather than the population of a conventional cemetery. The first experiments illustrate why the published demographic data (e.g. mortality, life expectancy, mean age at death) is misleading. It is illogical to utilise mortality tables devised for conventional (attritional) cemeteries in the case of living populations. Modelled populations with the published mortality rates of the massacre site are, furthermore, unable to stand up to plausible human demographic circumstances. In the second part, we evaluate the actual demographic information content of the Talheim sample. Comparative modelling illustrates that the Talheim population appears to be similar to possible living populations based on the mortuary record of Schwetzingen, an isochronal site of the Linear Pottery Culture (LBK), and Bärenthal, a site which dates back to the early medieval period (7th to 10th centuries). It is therefore very likely that the Talheim population is a representative sample of a living population in the LBK and might even represent a massacred village community in its entirety.

Human population reduction is not a quick fix for environmental problems.

The inexorable demographic momentum of the global human population is rapidly eroding Earth's life-support system. There are consequently more frequent calls to address environmental problems by advocating further reductions in human fertility. To examine how quickly this could lead to a smaller human population, we used scenario-based matrix modeling to project the global population to the year 2100. Assuming a continuation of current trends in mortality reduction, even a rapid transition to a worldwide one-child policy leads to a population similar to today's by 2100. Even a catastrophic mass mortality event of 2 billion deaths over a hypothetical 5-y window in the mid-21(st) century would still yield around 8.5 billion people by 2100. In the absence of catastrophe or large fertility reductions (to fewer than two children per female worldwide), the greatest threats to ecosystems--as measured by regional projections within the 35 global Biodiversity Hotspots--indicate that Africa and South Asia will experience the greatest human pressures on future ecosystems. Humanity's large demographic momentum means that there are no easy policy levers to change the size of the human population substantially over coming decades, short of extreme and rapid reductions in female fertility; it will take centuries, and the long-term target remains unclear. However, some reduction could be achieved by midcentury and lead to hundreds of millions fewer people to feed. More immediate results for sustainability would emerge from policies and technologies that reverse rising consumption of natural resources.

Fulminant myocarditis complicated with cardiac arrest and subsequent acute respiratory distress syndrome formation rescued by Extracorporeal Membrane Oxygenation – A rare case report

Acute fulminant myocarditis (AFM) is a relatively rare diagnosis characterized by heart failure preceded by symptoms of viral infection. Sometimes circulatory mechanical support is required for this catastrophic condition and mortality rate was still high. Adult respiratory distress syndrome (ARDS) was a rare complication of myocarditis in the literature. However, there was limited literature discussing AFM complicated with cardiac arrest and subsequent ARDS formation and the prognosis of extracorporeal membrane oxygenation (ECMO) treatment is unknown. Here we report a case of AFM suffering from cardiac arrest and ARDS formation and successfully treated by ECMO. This rare case reminds physicians that ARDS is still a possible but extremely rare complication of fulminant myocarditis, and ECMO is a lifesaving treatment not only for AFM with profound shock but also for possible ARDS formation.

The rise of the mediocre forest: why chronically stressed trees may better survive extreme episodic climate variability

Anthropogenic climate change is a relatively new phenomenon, largely occurring over the past 150 years, and much of the discussion on climate change impacts to forests has focused on long-term shifts in temperature and precipitation. However, individual trees respond to the much shorter impacts of climate variability. Historically, fast growing, fully canopied, non-chronically stressed (NCS) trees (e.g., those with minimal insect or disease damage, growing on high nutrient, moist soils), have been considered the model of individual health, while slower growing, broken crown, chronically stressed (CS) trees growing on nutrient poor, or dry soils, were considered to be unhealthy and prone to stress related mortality. Over the coming years and decades, climate variability (e.g., extreme precipitation events, drought, heat waves) is expected to increase. We hypothesize that as the duration, severity and interaction of stress becomes more pronounced under increasing climate variability, seemingly less healthy, CS trees could begin to survive environmental stress better than their traditionally considered healthy, NCS tree counterparts. We further hypothesize that this shift in survivorship will be attributed to tree response to increasingly extreme climate variability at levels not previously observed in recorded history. While NCS trees can better survive historic episodic stress, we hypothesize that CS trees may be better suited to survive the combination of chronic low-level stress, and extreme episodic stress associated with anthropogenic climate change and increasing climate variability. Specifically, morphological differences such as increased root and reduced leaf mass, and physiological differences such as more oleoresin production, could make slower growing, CS forests more resilient to catastrophic episodic mortality compared to more NCS stands under certain circumstances. General circulation models suggest that climate variability will increase in the future. Therefore, the occurrence of slow growth, CS forest stands out surviving faster growing NCS less stressed stands may become more common place, and eventually lead to ''The Age of the Mediocre Forest''. This paper addresses the type of envi- ronmental conditions that could create such an inverse in forest health conditions, and the implications that this shift might have in forest genetics and management.

Black band disease as a possible factor of the coral decline at the northern reef-flat of Yongxing Island, South China Sea

Black band disease (BBD), characterized by the Cyanobacterial dominated pathogenic consortium, is thought to play a key role in the global decline of the coral reef ecosystems. The present paper originally documents a case of BBD from Yongxing Island (Xisha Islands, South China Sea), and further probes the reasons of this abnormal phenomenon. Prior to 2007, corals at northern reef-flat of Yongxing Isand were in healthy growth. Catastrophic coral mortality occurred between 2007 and 2008. The 16S rRNA gene sequencing and PCR amplification, with universally conserved primers, were applied to detect the contagious bacterial community of the microbial mat. The results demonstrated that six bacterial divisions constituted the clone libraries derived from the BBD mat, and that Cyanobacteria are the most diversely represented group that inhabit BBD bacterial mats, despite the fact that species in five others divisions (α-Proteobacteria, γ-Proteobacteria, Bacteroidetes, Verrucomicrobia and Actinobacteria) are also consistently diverse within the BBD mats of diseased coral. Other factors such as coral bleaching, typhoons, ocean acidification and crown-of-thorns starfish outbreaks, are not primarily responsible for the coral mortality within such a short time interval. The disaster expansion of BBD associated with Cyanobacterial blooms is a more likely mechanism impacting these coral reefs. Excessive human activity enhances the eutrophication of the marine water of the reefal region and may result in occurrence of the BBD.

Temperature Variability in a Subtropical Estuary and Implications for Common Snook Centropomus undecimalis, a Cold-Sensitive Fish

Variability in winter water temperature was compared among three habitat types (estuary, river, canal) in a subtropical estuarine system to explore how it might affect site selection and survival of a cold-sensitive fish, Common Snook Centropomus undecimalis. The study was conducted during three winters (2008–2010); a rapid cooling event occurred during the first winter, mild temperatures the second, and an extreme cold event in the third (an 80-yr event). During the extreme cold event in January 2010, catastrophic fish mortality occurred throughout the region that resulted in the emergency closure of the Common Snook recreational fishery. Over the entire studied estuarine system, dead Common Snook were reported at 43 sites; 26 of the sites were large fish kills consisting of 100–2,000 individuals. The distribution of mortality sites was widespread, although most were located in the estuary proper (n = 39), with only several in rivers and canals (n = 4). Temperature loggers recorded similar water temperatures among habitat types (estuary, river, canal), except during short periods (~3 d; up to 2°C) after cold fronts; this indicates that fish have distinct time constraints if searching for warmer water sites. During the short periods after cold fronts, canal water temperatures were the warmest and most stable, whereas the river and estuary temperature rankings varied.