scholarly journals Worldwide reef surveys highlight different adaptive responses to heat between coral taxa

2021 ◽  
Author(s):  
Oliver Selmoni ◽  
Gael Lecellier ◽  
Veronique Berteaux-Lecellier ◽  
Stephane Joost
Keyword(s):  
Heat Stress ◽  
Heat Waves ◽  
Coral Cover ◽  
Heat Exposure ◽  
Negative Association ◽  
Conservation Strategies ◽  
Long Term Effects ◽  
Thermal Anomalies ◽  
Adaptive Processes

Coral reefs around the world are under threat due to widespread decline of hard corals caused by anomalous heat waves. Coral taxa of different morphologies are known to have different sensitivities to heat stress. However, little is known about how long-term effects of heat exposure differ between coral taxa, nor in particular how such effects might drive adaptive processes. Here, we combined worldwide reef survey data with remotely sensed thermal anomalies to evaluate how local rates of taxa-specific coral cover were associated with heat stress. We found a negative association between coral cover and heat stress, where associations were weaker for corals with boulder-like morphology (massive corals), intermediate for corals with arborescent morphology (branching corals) and stronger for corals with encrusting or laminar morphology (plating corals). Additionally, we found that the negative association between branching coral cover and recent exposure to heat stress (measured as the year before a survey) was mitigated by the effect of long-term heat stress (measured since 1985), suggesting that adaptive processes occurred. In contrast, this "mitigating effect" of past heat-stress was not observed for either massive or plating corals. We hypothesize that these different responses to recent and past heat stress mirror different life history traits of coral taxa. For instance, branching corals are known to show higher sensitivities to heat stress and faster growth rates, two characteristics that might boost adaptive rates via evolutionary processes, when compared with other taxa. The results of this work suggest that all coral taxa, regardless of their morphology, will be "losers" of coral bleaching, and that conservation strategies should be adjusted to match taxa-specific responses to heat stress.

scholarly journals Coral cover surveys corroborate predictions on reef adaptive potential to thermal stress

2020 ◽  
Author(s):  
Oliver Selmoni ◽  
Gaël Lecellier ◽  
Laurent Vigliola ◽  
Véronique Berteaux-Lecellier ◽  
Stéphane Joost
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Coral Reefs ◽  
Spatial Patterns ◽  
New Caledonia ◽  
Heat Waves ◽  
Coral Cover ◽  
Thermal Adaptation ◽  
Conservation Strategies ◽  
Adaptive Potential

AbstractAs anomalous heat waves are causing the widespread decline of coral reefs worldwide, there is an urgent need to identify coral populations tolerant to thermal stress. Heat stress adaptive potential is the degree of tolerance expected from evolutionary processes and, for a given reef, depends on the arrival of propagules from reefs exposed to recurrent thermal stress. For this reason, assessing spatial patterns of thermal adaptation and reef connectivity is of paramount importance to inform conservation strategies.In this work, we applied a seascape genomics framework to characterize the spatial patterns of thermal adaptation and connectivity for coral reefs of New Caledonia (Southern Pacific). In this approach, remote sensing of seascape conditions was combined with genomic data from three coral species. For every reef of the region, we computed a probability of heat stress adaptation, and two indices forecasting inbound and outbound connectivity. We then compared our indicators to field survey data, and observed that decrease of coral cover after heat stress was lower at reefs predicted with high probability of adaptation and inbound connectivity. Last, we discussed how these indicators can be used to inform local conservation strategies and preserve the adaptive potential of New Caledonian reefs.

scholarly journals Coral cover surveys corroborate predictions on reef adaptive potential to thermal stress

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Oliver Selmoni ◽  
Gaël Lecellier ◽  
Laurent Vigliola ◽  
Véronique Berteaux-Lecellier ◽  
Stéphane Joost
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Coral Reefs ◽  
Spatial Patterns ◽  
New Caledonia ◽  
Heat Waves ◽  
Coral Cover ◽  
Thermal Adaptation ◽  
Conservation Strategies ◽  
Adaptive Potential

AbstractAs anomalous heat waves are causing the widespread decline of coral reefs worldwide, there is an urgent need to identify coral populations tolerant to thermal stress. Heat stress adaptive potential is the degree of tolerance expected from evolutionary processes and, for a given reef, depends on the arrival of propagules from reefs exposed to recurrent thermal stress. For this reason, assessing spatial patterns of thermal adaptation and reef connectivity is of paramount importance to inform conservation strategies. In this work, we applied a seascape genomics framework to characterize the spatial patterns of thermal adaptation and connectivity for coral reefs of New Caledonia (Southern Pacific). In this approach, remote sensing of seascape conditions was combined with genomic data from three coral species. For every reef of the region, we computed a probability of heat stress adaptation, and two indices forecasting inbound and outbound connectivity. We then compared our indicators to field survey data, and observed that decrease of coral cover after heat stress was lower at reefs predicted with high probability of adaptation and inbound connectivity. Last, we discussed how these indicators can be used to inform local conservation strategies and preserve the adaptive potential of New Caledonian reefs.

scholarly journals Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Thais Rose dos Santos Hamilton ◽  
Camilla Mota Mendes ◽  
Letícia Signori de Castro ◽  
Patrícia Monken de Assis ◽  
Adriano Felipe Perez Siqueira ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heat Stress ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Treated Group ◽  
Epididymal Sperm ◽  
Long Term Effects ◽  
Stressed Cells

Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm.

scholarly journals Heat and dehydration induced oxidative damage and antioxidant defenses following incubator heat stress and a simulated heat wave in wild caught four-striped field mice Rhabdomys dilectus

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242279
Author(s):  
Paul J. Jacobs ◽  
M. K. Oosthuizen ◽  
C. Mitchell ◽  
Jonathan D. Blount ◽  
Nigel C. Bennett
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Heat Stress ◽  
Oxidative Damage ◽  
Heat Wave ◽  
Body Mass ◽  
Heat Waves ◽  
Heat Exposure ◽  
Field Mice ◽  
The Brain

Heat waves are known for their disastrous mass die-off effects due to dehydration and cell damage, but little is known about the non-lethal consequences of surviving severe heat exposure. Severe heat exposure can cause oxidative stress which can have negative consequences on animal cognition, reproduction and life expectancy. We investigated the current oxidative stress experienced by a mesic mouse species, the four striped field mouse, Rhabdomys dilectus through a heat wave simulation with ad lib water and a more severe temperature exposure with minimal water. Wild four striped field mice were caught between 2017 and 2019. We predicted that wild four striped field mice in the heat wave simulation would show less susceptibility to oxidative stress as compared to a more severe heat stress which is likely to occur in the future. Oxidative stress was determined in the liver, kidney and brain using malondialdehyde (MDA) and protein carbonyl (PC) as markers for oxidative damage, and superoxide dismutase (SOD) and total antioxidant capacity (TAC) as markers of antioxidant defense. Incubator heat stress was brought about by increasing the body temperatures of animals to 39–40.8°C for 6 hours. A heat wave (one hot day, followed by a 3-day heatwave) was simulated by using temperature cycle that wild four striped field mice would experience in their local habitat (determined through weather station data using temperature and humidity), with maximal ambient temperature of 39°C. The liver and kidney demonstrated no changes in the simulated heat wave, but the liver had significantly higher SOD activity and the kidney had significantly higher lipid peroxidation in the incubator experiment. Dehydration significantly contributed to the increase of these markers, as is evident from the decrease in body mass after the experiment. The brain only showed significantly higher lipid peroxidation following the simulated heat wave with no significant changes following the incubator experiment. The significant increase in lipid peroxidation was not correlated to body mass after the experiment. The magnitude and duration of heat stress, in conjunction with dehydration, played a critical role in the oxidative stress experienced by each tissue, with the results demonstrating the importance of measuring multiple tissues to determine the physiological state of an animal. Current heat waves in this species have the potential of causing oxidative stress in the brain with future heat waves to possibly stress the kidney and liver depending on the hydration state of animals.

Immediate and potential long-term effects of consecutive heat waves on the photosynthetic performance and water balance in Douglas-fir

2016 ◽  
Vol 205 ◽  
pp. 57-66 ◽  
Author(s):  
André G. Duarte ◽  
Genki Katata ◽  
Yasutomo Hoshika ◽  
Mohitul Hossain ◽  
Jürgen Kreuzwieser ◽  
...  
Keyword(s):  
Water Balance ◽  
Heat Waves ◽  
Photosynthetic Performance ◽  
Douglas Fir ◽  
Long Term Effects

scholarly journals Reduced thermal tolerance of massive coral species in a highly variable environment

2020 ◽  
Vol 287 (1933) ◽  
pp. 20201379 ◽  
Author(s):  
C. N. Klepac ◽  
D. J. Barshis
Keyword(s):  
Heat Stress ◽  
Thermal Tolerance ◽  
Coral Cover ◽  
Thermal Anomaly ◽  
American Samoa ◽  
Variable Environment ◽  
Thermal Anomalies ◽  
Thermal Environments ◽  
Acute Heat Stress ◽  
Species Specific

Coral bleaching events are increasing in frequency and severity, resulting in widespread losses in coral cover. However, branching corals native to highly variable (HV) thermal environments can have higher bleaching resistance than corals from more moderate habitats. Here, we investigated the response of two massive corals, Porites lobata and Goniastrea retiformis , from a moderately variable (MV) and a low variability (LV) pool transplanted into a HV pool on Ofu Island in American Samoa. Paired transplant and native ramets were exposed to an acute thermal stress after 6 and 12 months of exposure to the HV pool to evaluate changes in thermal tolerance limits. For both species, photosynthetic efficiency and chlorophyll loss following acute heat stress did not differ between ramets transplanted into the HV pool and respective native pool. Moreover, HV native P. lobata exhibited the greatest bleaching susceptibility compared to MV and LV natives and there was no effect of acute heat stress on MV P. lobata . There was also a thermal anomaly during the study, where Ofu's backreef thermal regime surpassed historical records—2015 had 8 degree heating weeks (DHW) and 2016 had up to 5 DHW (in comparison to less than or equal to 3 over the last 10 years)—which may have exceeded the upper thermal limits of HV native P. lobata . These results strongly contrast with other research on coral tolerance in variable environments, potentially underscoring species-specific mechanisms and regional thermal anomalies that may be equally important in shaping coral responses to extreme temperatures.

scholarly journals Differential tolerance and resilience of Mediterranean seagrasses to short-term heat stress

2015 ◽  
Author(s):  
Lazaro Marin-Guirao ◽  
Emanuela Dattolo ◽  
Juan Manuel Ruiz ◽  
Gabriele Procaccini
Keyword(s):  
Heat Stress ◽  
Recovery Period ◽  
Heat Exposure ◽  
Photochemical Efficiency ◽  
Posidonia Oceanica ◽  
Conservation Strategies ◽  
Physiological Status ◽  
Negative Effects ◽  
Experimental Conditions ◽  
Interspecific Differences

The aim of the present study was to determine tolerance to ocean warming of the two main Mediterranean seagrass species Posidonia oceanica and Cymodocea nodosa. To this end, photophysiological and transcriptomic responses of shallow (5m) and deep (25m) plants were studied during a 5-d exposure to heat (32°C) and after a 5-d recovery to ambient temperature (24°C). Observed responses evidenced interspecific differences in heat tolerance in accordance with the biological attributes and ecological strategies of the species, but also intraspecific differences in relation to the depth origin of plants. The smaller and fast-growing species C. nodosa, was able to maintain unaltered leaf carbon budget along heat exposure, thanks to proportionally similar increments in photosynthesis and respiration. Along with this, the lack of alterations at the photochemical and photoprotective levels point to a high tolerance of the species to heat stress. Contrarily, the higher increment in respiration than in photosynthesis showed by the long-lived and slow-growing P. oceanica provoked leaf carbon imbalance after 24h of heat exposure, evidencing its higher sensitivity to heat. Interestingly, shallow plants displayed a higher acclimation capacity and after 5d of exposure their photosynthetic and respiratory rates converged to control conditions, whereas deep plants still evidenced symptoms of heat stress. The progressive photochemical efficiency reduction observed in deep plants, reinforced the idea that deeps plants are less able to tolerate heat. In any case, plants from both depths were able to recover their physiological status after a recovery period, indicating that they did not suffer lethal injury under the experimental conditions here tested. An analysis of gene expression (both RT-qPCR and RNA-seq) is ongoing, to dig into the molecular and physiological mechanisms involved in seagrass tolerance to heat stress. In conclusion, the study suggests that warming caused by human-induced climate change will likely have significant negative effects mainly on P. oceanica populations. The sensibility of the species to heat will finally depend on the local environmental conditions where plants grow (e.g. different depths or latitudes), a fact that must be taken in to account for the establishment of suitable management and conservation strategies.

scholarly journals Long term cyclic heat stress influences physiological responses and blood characteristics in indigenous sheep

2013 ◽  
Vol 42 (2) ◽  
pp. 96-100 ◽  
Author(s):  
MM Rashid ◽  
MM Hossain ◽  
MAK Azad ◽  
MA Hashem
Keyword(s):  
Heat Stress ◽  
Heat Exposure ◽  
Blood Parameters ◽  
Heat Treatments ◽  
Control Group ◽  
Short Term ◽  
Nitrogen Levels ◽  
Indigenous Sheep ◽  
Cyclic Heat

The present study was designed to elucidate changes in physiological and blood parameters of indigenous sheep during cyclic heat exposure. Twelve 2-4 year-old sheep with an average body weight of 10.5±0.5 kg were randomly allocated to one of three experimental heat treatments: control (21°C, stall feeding), short term (21°C to 32°C; 32°C for 4 h/d, grazing), and long term (21°C to 32°; 32°C for 8 h/d, grazing).The results have shown that sheep exposed to cyclic heat treatments exhibited higher (P=0.05) rectal temperature, body temperature, and respiratory rate compared to the control group. Cyclic heat treatments significantly decreased heart rate of sheep. There was a sharp reduction in rumination and an increase in time spent by sheep in eating during cyclic heat treatments. Long term heat treatment significantly increased RBC and WBC counts, PCV values, and hemoglobin level than that of the control and short term heat treatments. Similar responses were also observed in plasma glucose, uric acid, aspartate aminotransferase, and blood urea nitrogen levels. These results suggest that short term heat stress is tolerable but long term is physiologically detrimental to them to indigenous sheep.DOI: http://dx.doi.org/10.3329/bjas.v42i2.18486 Bang. J. Anim. Sci. 2013. 42 (2): 96-100

Effect of heat stress on LPS-induced fever and tumor necrosis factor

1997 ◽  
Vol 273 (3) ◽  
pp. R858-R863 ◽  
Author(s):  
M. J. Kluger ◽  
K. Rudolph ◽  
D. Soszynski ◽  
C. A. Conn ◽  
L. R. Leon ◽  
...  
Keyword(s):  
Heat Stress ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Human Subjects ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Male Rats ◽  
Long Term Effects ◽  
Inflammatory Stimuli ◽  
Necrosis Factor

Exposure to heat stress leads to both short-term and long-term effects on morbidity. Male rats were exposed to a high ambient temperature of 40 degrees C, which resulted in biotelemetered core body temperature rising to approximately 42 degrees C. This treatment led to a marked enhancement in lipopolysaccharide (LPS)-induced fever at 24 h after exposure to heat stress. The increase in fever was accompanied by a significant suppression in the circulating concentration of tumor necrosis factor. Heat-shock protein-70 measured in liver was elevated by the heat exposure (but not further elevated by the injection of LPS). An enhanced fever to LPS and other inflammatory stimuli found in heat-stressed human subjects could explain the apparent increase in susceptibility to disease.

Sign in / Sign up

Export Citation Format

Share Document