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Anthropogenic impacts are typically detrimental to tropical coral reefs, but the effect of increasing environmental stress and variability on the size structure of coral communities remains poorly understood. This limits our ability to effectively conserve coral reef ecosystems because size specific dynamics are rarely incorporated. Our aim is to quantify variation in the size structure of coral populations across 20 sites along a tropical‐to‐subtropical environmental gradient on the east coast of Australia (~ 23 to 30°S), to determine how size structure changes with a gradient of sea surface temperature, turbidity, productivity and light levels. We use two approaches: 1) linear regression with summary statistics (such as median size) as response variables, a method frequently favoured by ecologists and 2) compositional functional regression, a novel method using entire size–frequency distributions as response variables. We then predict coral population size structure with increasing environmental stress and variability. Together, we find fewer but larger coral colonies in marginal reefs, where conditions are typically more variable and stressful, than in tropical reefs. Our model predicts that coral populations may become gradually dominated by larger colonies (> 148 cm2) with increasing environmental stress. Fewer but bigger corals suggest low survival of smaller corals, slow growth, and/or poor recruitment. This finding is concerning for the future of coral reefs, as it implies that current marginal populations, or future reefs in increasingly stressful environmental conditions may have low recovery potential. We highlight the importance of continuously monitoring changes to population structure over biogeographic scales. [ABSTRACT FROM AUTHOR]

The persistent exposure of coral assemblages to more variable abiotic regimes is assumed to augment their resilience to future climatic variability. Yet, while the determinants of coral population resilience across species remain unknown, we are unable to predict the winners and losers across reef ecosystems exposed to increasingly variable conditions. Using annual surveys of 3171 coral individuals across Australia and Japan (2016–2019), we explore spatial variation across the short‐ and long‐term dynamics of competitive, stress‐tolerant, and weedy assemblages to evaluate how abiotic variability mediates the structural composition of coral assemblages. We illustrate how, by promoting short‐term potential over long‐term performance, coral assemblages can reduce their vulnerability to stochastic environments. However, compared to stress‐tolerant, and weedy assemblages, competitive coral taxa display a reduced capacity for elevating their short‐term potential. Accordingly, future climatic shifts threaten the structural complexity of coral assemblages in variable environments, emulating the degradation expected across global tropical reefs. [ABSTRACT FROM AUTHOR]

Escalating climatic and anthropogenic pressures expose ecosystems worldwide to increasingly stochastic environments. Yet, our ability to forecast the responses of natural populations to this increased environmental stochasticity is impeded by a limited understanding of how exposure to stochastic environments shapes demographic resilience. Here, we test the association between local environmental stochasticity and the resilience attributes (e.g. resistance, recovery) of 2242 natural populations across 369 animal and plant species. Contrary to the assumption that past exposure to frequent environmental shifts confers a greater ability to cope with current and future global change, we illustrate how recent environmental stochasticity regimes from the past 50 years do not predict the inherent resistance or recovery potential of natural populations. Instead, demographic resilience is strongly predicted by the phylogenetic relatedness among species, with survival and developmental investments shaping their responses to environmental stochasticity. Accordingly, our findings suggest that demographic resilience is a consequence of evolutionary processes and/or deep‐time environmental regimes, rather than recent‐past experiences. [ABSTRACT FROM AUTHOR]

Predicting the viability of species exposed to increasing climatic stress requires an appreciation for the mechanisms underpinning the success or failure of marginal populations. Rather than traditional metrics of long‐term population performance, here we illustrate that short‐term (i.e. transient) demographic characteristics, including measures of resistance, recovery and compensation, are fundamental in the poleward range expansion of hard corals, facilitating the establishment of coral populations at higher latitudes. Through the annual census of subtropical and temperate Acropora spp. colonies in Japan between 2017 and 2019, we show how enhanced transient amplification (i.e. short‐term increases in population growth following disturbance) supports the persistence of coral assemblages within more variable high‐latitude environments. The transient dynamics of both the subtropical and temperate assemblages were strongly influenced by their corresponding recruitment patterns. However, we demonstrate that variation in colony survival and fragmentation patterns between the two assemblages determines their relative capacities for transient amplification. This latitudinal variation in the transient dynamics of Acropora spp. assemblages emphasizes that coral populations can possess the demographic plasticity necessary for exploiting more variable, marginal conditions. [ABSTRACT FROM AUTHOR]

Accelerating rates of biodiversity loss underscore the need to understand how species achieve resilience—the ability to resist and recover from a/biotic disturbances. Yet, the factors determining the resilience of species remain poorly understood, due to disagreements on its definition and the lack of large‐scale analyses. Here, we investigate how the life history of 910 natural populations of animals and plants predicts their intrinsic ability to be resilient. We show that demographic resilience can be achieved through different combinations of compensation, resistance and recovery after a disturbance. We demonstrate that these resilience components are highly correlated with life history traits related to the species' pace of life and reproductive strategy. Species with longer generation times require longer recovery times post‐disturbance, whilst those with greater reproductive capacity have greater resistance and compensation. Our findings highlight the key role of life history traits to understand species resilience, improving our ability to predict how natural populations cope with disturbance regimes. [ABSTRACT FROM AUTHOR]

Subtropical coral assemblages are threatened by similar extreme thermal stress events to their tropical counterparts. Yet, the mid‐ and long‐term thermal stress responses of corals in subtropical environments remain largely unquantified, limiting our capacity to predict their future viability.The annual survival, growth and recruitment of 311 individual corals within the Solitary Islands Marine Park (Australia) was recorded over a 3‐year period (2016–2018), including the 2015/2016 thermal stress event. These data were used to parameterise integral projection models quantifying the effect of thermal stress within a subtropical coral assemblage. Stochastic simulations were also applied to evaluate the implications of recurrent thermal stress scenarios predicted by four different Representative Concentration Pathways.We report differential shifts in population growth rates (λ) among coral populations during both stress and non‐stress periods, confirming contrasting bleaching responses among taxa. However, even during non‐stress periods, the observed dynamics for all taxa were unable to maintain current community composition, highlighting the need for external recruitment sources to support the community structure.Across all coral taxa, projected stochastic growth rates (λs) were found to be lowest under higher emissions scenarios. Correspondingly, predicted increases in recurrent thermal stress regimes may accelerate the loss of coral coverage, species diversity and structural complexity within subtropical regions.We suggest that these trends are primarily due to the susceptibility of subtropical specialists and endemic species, such as Pocillopora aliciae, to thermal stress. Similarly, the viability of many tropical coral populations at higher latitudes is highly dependent on the persistence of up‐current tropical systems. As such, the inherent dynamics of subtropical coral populations appear unable to support their future persistence under unprecedented thermal disturbance scenarios. [ABSTRACT FROM AUTHOR]

The zooxanthellate scleractinian species Goniopora stokesi is widely distributed across the Indo-Pacific Ocean, and in Japan the northernmost records of this species are from Tatsukushi, Kochi on Shikoku, although these records are not associated with specimens deposited in museums. The species is unique among Goniopora in that it lives on soft bottom sediment, forming free-living colonies, and produces asexual daughter colonies, or "polyp balls," via budding from parent colonies. Here we report on a large G. stokesi community from Otsuki, Kochi, Japan, representing the northernmost specimen-based record of the species. Specimen-based records are important as verifiable baseline data in light of global warming and climate change, which is expected to drastically effect the marine flora and fauna of Kochi and surrounding areas. [ABSTRACT FROM AUTHOR]

Abstract: The grey gurnard Eutrigla gurnardus (L.) has been identified by ICES as a potential commercial species in the NE Atlantic with recommendations made to derive information on population biology for stock assessment purposes. However, data on the population biology of this species is limited. In this study, data on the age, growth and maturity of grey gurnard were collected by otter trawling in the coastal waters of northwest Wales and Eastern Anglesey. Total length (TL) of fish sampled ranged between 2.1–33.0 cm (male) and 1.9–36.9 cm (female) with the majority of female (70.8%) fish between 11 and 20 cm TL and male fish (70.5%) between 11 and 18 cm TL. The percentage of fish >20 cm TL was larger for females (30.4%) compared to males (17.6%). Total weight (TW) for female and male grey gurnard in the stratified subsample ranged from 1.9 to 499.9 g for females and 2.1–390.0 g for males, with the majority of female (66.3%) and male (76.1%) fish between 10 and 60 g. TL/TW relations for male and female fish and both sexes combined were: TW = 0.006TL3.07, TW = 0.007TL3.03 and TW = 0.007TL3.05 respectively. Age structure (based on otolith reading) ranged between 0.5 and 7.5 years old for females and 0.5 to 5.5 years old for male with the majority of female (41.7%) and male (46.0%) fish aged as 1.5 years old. The age structure of female and male grey gurnards was significantly different with the majority of older fish (>2.5 years) being female. The von Bertalanffy growth functions were calculated as Lt = 32.4[1 − e−0.24(t + 1.41)] for males, Lt = 45.9[1 − e−0.16(t + 1.37)] for females and Lt = 44.0[1 − e−0.18(t + 1.20)] for both sexes combined. Instantaneous rates of total mortality were similar for males and females and the combined Z value 1.00 year−1 with the natural mortality rate estimated as 0.33 year−1. The size at 50% maturity (L50) was estimated to be 25.3 cm TL for males, females and for both sexes combined. Age at 50% maturity (A50) was 3.2 years for both males and females. The results of this study provide the first information on the population biology of E. gurnardus in the Irish Sea, the first detailed study in the NE Atlantic since 1985 and helps to address the data gap identified by ICES in knowledge of the population biology of this species. [ABSTRACT FROM AUTHOR]

Experimental coronary artery disease (CAD) was produced in dogs which had chronically implanted catheters for the measurement of mean arterial pressure (MAP) and coronary blood flow (CBF) using the 85Kr clearance technique. Resting CBF was determined in the conscious animal during intracoronary infusion of saline and the 'maximum' CBF was determined by infusion of ATP (0s·6 and 0·8 mg/min). Repeated observations revealed only small and variable changes in MAP and CBF of control dogs over a two-month period and of dogs fed an atherogenic diet containing thiouracil and cholesterol for 47 and 54 days. CAD was produced by intracoronary infusion of allylamine and intravenous infusion of egg yolk emulsion. This treatment results in arteritis, lipid deposition, and fibrosis. The disease was associated with a 37% decrease in maximum CBF within two to five days. Resting CBF decreased 16% and MAP was not altered significantly. After the initial decrease in maximum CBF, there is a stable period with decreased maximum CBF for at least six weeks. [ABSTRACT FROM PUBLISHER]