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Interest is growing in developing conservation strategies to restore and maintain coral reef ecosystems in the face of mounting anthropogenic stressors, particularly climate warming and associated mass bleaching events. One such approach is to propagate coral colonies ex situ and transplant them to degraded reef areas to augment habitat for reef-dependent fauna, prevent colonization from spatial competitors, and enhance coral reproductive output. In addition to such demographic restoration efforts, manipulating the thermal tolerance of outplanted colonies through assisted relocation, selective breeding, or genetic engineering is being considered for enhancing rates of evolutionary adaptation to warming. Although research into such assisted evolution strategies has been growing, their expected performance remains unclear. We evaluated the potential outcomes of demographic restoration and assisted evolution in climate change scenarios using an eco-evolutionary simulation model. We found that supplementing reefs with pre-existing genotypes (demographic restoration) offers little climate resilience benefits unless input levels are large and maintained for centuries. Supplementation with thermally resistant colonies was successful at improving coral cover at lower input levels, but only if maintained for at least a century. Overall, we found that, although demographic restoration and assisted evolution have the potential to improve long-term coral cover, both approaches had a limited impact in preventing severe declines under climate change scenarios. Conversely, with sufficient natural genetic variance and time, corals could readily adapt to warming temperatures, suggesting that restoration approaches focused on building genetic variance may outperform those based solely on introducing heat-tolerant genotypes.

Corals are experiencing unprecedented decline from climate change-induced mass bleaching events. Dispersal not only contributes to coral reef persistence through demographic rescue but can also hinder or facilitate evolutionary adaptation. Locations of reefs that are likely to survive future warming therefore remain largely unknown, particularly within the context of both ecological and evolutionary processes across complex seascapes that differ in temperature range, strength of connectivity, network size, and other characteristics. Here, we used eco-evolutionary simulations to examine coral adaptation to warming across reef networks in the Caribbean, the Southwest Pacific, and the Coral Triangle. We assessed the factors associated with coral persistence in multiple reef systems to understand which results are general and which are sensitive to particular geographic contexts. We found that evolution can be critical in preventing extinction and facilitating the long-term recovery of coral communities in all regions. Furthermore, the strength of immigration to a reef (destination strength) and current sea surface temperature robustly predicted reef persistence across all reef networks and across temperature projections. However, we found higher initial coral cover, slower recovery, and more evolutionary lag in the Coral Triangle, which has a greater number of reefs and more larval settlement than the other regions. We also found the lowest projected future coral cover in the Caribbean. These findings suggest that coral reef persistence depends on ecology, evolution, and habitat network characteristics, and that, under an emissions stabilization scenario (RCP 4.5), recovery may be possible over multiple centuries.

Global environmental change is challenging species with novel conditions, such that demographic and evolutionary trajectories of populations are often shaped by the exchange of organisms and alleles across landscapes. Current ecological theory predicts that random networks with dispersal shortcuts connecting distant sites can promote persistence when there is no capacity for evolution. Here, we show with an eco-evolutionary model that dispersal shortcuts across environmental gradients instead hinder persistence for populations that can evolve because long-distance migrants bring extreme trait values that are often maladaptive, short-circuiting the adaptive response of populations to directional change. Our results demonstrate that incorporating evolution and environmental heterogeneity fundamentally alters theoretical predictions regarding persistence in ecological networks.

Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change.

Globally, lake surface water temperatures have warmed rapidly relative to air temperatures, but changes in deepwater temperatures and vertical thermal structure are still largely unknown. We have compiled the most comprehensive data set to date of long-term (1970-2009) summertime vertical temperature profiles in lakes across the world to examine trends and drivers of whole-lake vertical thermal structure. We found significant increases in surface water temperatures across lakes at an average rate of + 0.37 °C decade-1, comparable to changes reported previously for other lakes, and similarly consistent trends of increasing water column stability (+ 0.08 kg m-3 decade-1). In contrast, however, deepwater temperature trends showed little change on average (+ 0.06 °C decade-1), but had high variability across lakes, with trends in individual lakes ranging from - 0.68 °C decade-1 to + 0.65 °C decade-1. The variability in deepwater temperature trends was not explained by trends in either surface water temperatures or thermal stability within lakes, and only 8.4% was explained by lake thermal region or local lake characteristics in a random forest analysis. These findings suggest that external drivers beyond our tested lake characteristics are important in explaining long-term trends in thermal structure, such as local to regional climate patterns or additional external anthropogenic influences.

Emerging evidence suggests that zooplankton production is affected by physiological and nutritional constraints due to climate change and eutrophication, which in turn could have broad implications for food-web dynamics and fisheries production. In this study, we developed a resource-based zooplankton production dynamics model that causally links freshwater cladoceran and copepod daily production-to-biomass (P/B) ratios with water temperature, phytoplankton biomass and community composition, and zooplankton feeding selectivity. This model was used to evaluate constraints on zooplankton growth under four hypothetical scenarios: involving natural plankton community seasonal succession; lake fertilization to enhance fisheries production; eutrophication; and climatic warming. Our novel modeling approach predicts zooplankton production is strongly dependent on seasonal variation in resource availability and quality, which results in more complex zooplankton dynamics than predicted by simpler temperature-dependent models. For mesotrophic and hypereutrophic lakes, our study suggests that the ultimate control over zooplankton P/B ratios shifts from physiological control during colder periods to strong resource control during warmer periods. Our resource-based model provides important insights into the nature of biophysical control of zooplankton under a changing climate that has crucial implications for food web energy transfer and fisheries production. De nouvelles observations semblent indiquer que des contraintes physiologiques et nutritives decoulant des changements climatiques et de l'eutrophisation ont une incidence sur la production de zooplancton, ce qui pourrait avoir de vastes repercussions sur la dynamique des reseaux trophiques et la production des peches. Nous avons developpe un modele de dynamique de la production de zooplancton base sur les ressources qui relie causalement les rapports quotidiens de la production et de la biomasse (P/B) de cladoceres et de copepodes d'eau douce a la temperature de l'eau, la biomasse et la composition de la communaute du phytoplancton et la selectivite de l'alimentation du zooplancton. Le modele est utilise pour evaluer les contraintes a la croissance du zooplancton dans quatre scenarios hypothetiques, a savoir : une succession saisonniere naturelle de la communaute de plancton, la fertilisation du lac pour accroitre la production des peches, l'eutrophisation et le rechauffement climatique. Notre nouvelle approche de modelisation predit que la production de zooplancton depend fortement des variations saisonnieres de la disponibilite et de la qualite des ressources, ce qui se traduit par une dynamique du zooplancton plus complexe que ce que predisent les modeles plus simples dependants de la temperature. Pour les lacs mesotrophes et hypereutrophes, l'etude indiquerait que les rapports P/B du zooplancton sont ultimement controles par la physiologie durant les periodes plus froides et par les ressources durant les periodes plus chaudes. Notre modele base sur les ressources fournit d'importants renseignements sur la nature du controle biophysique du zooplancton dans des conditions de climat changeant qui a d'importantes repercussions sur les transferts energetiques dans les reseaux trophiques et la production des peches. [Traduit par la Redaction], Introduction Zooplankton represent a biochemical filter in lakes wherein primary producer organic matter is converted to animal matter. Due to the large disparity in phytoplankton and zooplankton biochemical composition, energetic [...]

IntroductionA high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms.ObjectiveThe aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU.MethodsThis descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics.ResultsA total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients' annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient characteristics were compared in relation to 1) the number and 2) the duration of false arrhythmia alarms per 24-hour period, using nonparametric statistics to minimize the influence of outliers. Among the significant associations were the following: age ≥60 years (P=0.013; P=0.034), confused mental status (P

With advances in molecular genetics, it is becoming increasingly feasible to conduct genetic stock identification (GSI) to inform management actions that occur within a fishing season. While applications of in-season GSI are becoming widespread, such programs seldom integrate data from previous years, underutilizing the full breadth of information available for real-time inference. In this study, we developed a Bayesian hierarchical model that integrates historical and in-season GSI data to estimate temporal changes in the composition of a mixed stock of sockeye salmon (Oncorhynchus nerka) returning to Alaska's Chignik watershed across the fishing season. Simulations showed that even after accounting for time constraints of transporting and analyzing genetic samples, a hierarchical approach can rapidly achieve accurate in-season stock allocation, outperforming alternative methods that rely solely on historical or in-season data by themselves. As the distribution and phenology of fish populations becomes more variable and difficult to predict under climate change, in-season management tools will likely be increasingly relied upon to protect biocomplexity while maximizing harvest opportunity in mixed stock fisheries. Les avancees en genetique moleculaire font en sorte qu'il est de plus en plus envisageable d'utiliser l'identification genetique au stock (IGS) pour eclairer le choix des mesures de gestion a utiliser durant une saison de peche. Si les exemples d'application de l'IGS pour la saison en cours sont de plus en plus repandus, ces programmes integrent rarement les donnees d'annees precedentes, sous-utilisant donc le vaste eventail d'information disponible pour l'inference en temps reel. Nous avons developpe un modele hierarchique bayesien qui integre des donnees d'IGS passees et pour la saison en cours pour estimer les changements dans le temps de la composition d'un stock melange de saumons sockeyes (Oncorhynchus nerka) retournant dans le bassin versant de Chignik, en Alaska, au fil de la saison de peche. Des simulations montrent que, meme en tenant compte de contraintes temporelles associees au transport et a l'analyse des echantillons genetiques, une approche hierarchique peut permettre de realiser rapidement et avec exactitude l'affectation au stock au fil de la saison, donnant de meilleurs resultats que d'autres methodes qui reposent exclusivement sur des donnees passees ou pour la saison en cours. La repartition et la phenologie des populations de poissons devenant plus variables et difficiles a predire dans un contexte de changements climatiques, il y aura vraisemblablement un recours croissant a des outils de gestion reposant sur des donnees pour la saison en cours pour maintenir la biocomplexite tout en maximisant les possibilites de prises dans les peches de stocks melanges., Introduction Managing harvest that simultaneously targets multiple populations is a classic and common challenge in fisheries. Failing to account for such demographic heterogeneity can lead to biased estimates of biological [...]

While conservation and fisheries management are often concerned with changes in population abundance and distribution, shifts in population age-size structure are commonly observed in response to human and environmental stressors. Chinook salmon (Oncorhynchus tshawytscha) have experienced widespread declines in mean age and size throughout their North American range. We investigated the consequences of declines in body size for spawner reproductive potential in terms of total egg mass per female. Our case study is the Yukon River where Chinook salmon have supported subsistence, commercial, and recreational fisheries. Using historical observations on individual body size from throughout the Yukon River and the relationship between female size and total egg mass from the Canadian portion, we estimate a decline in average female reproductive potential of 24%-35% since the 1970s. Because spawner abundances and the population sex ratio have not shown clear trends over time, our results suggest a reduced total population reproductive potential. Changes in spawner quality should be considered when developing management reference points, and conservation of population demographic structure may be necessary to sustain productive Chinook salmon systems. Si les variations de l'abondance et de la repartition des populations sont des preoccupations repandues en conservation et en gestion des peches, des changements de la structure par age des populations en reponse a des facteurs de stress d'origine humaine ou environnementale sont couramment observes. Les saumons chinooks (Oncorhynchus tshawytscha) ont connu des baisses a grande echelle des ages et des tailles moyens dans toute leur aire de repartition nord-americaine. Nous avons examine les consequences de diminutions de la taille du corps sur le potentiel de reproduction des geniteurs represente par la masse totale des reufs des femelles. Notre etude a porte sur le fleuve Yukon, ou les saumons chinooks supportent des peches commerciales, sportives et de subsistance. En utilisant des observations passees sur la taille du corps individuelle a la grandeur du fleuve Yukon, ainsi que la relation entre la taille des femelles et la masse totale de leurs reufs dans le tron^on canadien, nous estimons une baisse du potentiel de reproduction moyen des femelles de 24 % a 35 % depuis les annees 1970. Comme les abondances de geniteurs et le rapport de masculinite de la population ne presentent pas de tendances claires dans le temps, nos resultats indiqueraient une diminution du potentiel de reproduction total de la population. Les variations de la qualite des geniteurs devraient etre prises en consideration dans l'etablissement de points de reference pour la gestion, et le maintien de la structure demographique des populations pourrait etre necessaire pour soutenir des systemes de saumons chinooks productifs. [Traduit par la Redaction], Introduction Conservation is most concerned with changes in the abundance and distribution of populations in response to human and environmental stressors. However, changes in life-history traits and demographic structure are [...]

Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985-2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues.