Seasonal Temperature Fluctuations Research Articles

Seasonally variable thermal performance curves prevent adverse effects of heatwaves.

1. Differential vulnerability to heatwaves may affect community dynamics in a changing climate. In temperate regions, this vulnerability to heatwaves depends on the interactions between seasonal temperature fluctuations and the capacity to rapidly shift thermal performance curves. 2. Here we investigate how these dynamics affect the vulnerability of two ecologically important copepod congeners, Acartia tonsa and A. hudsonica, to heatwaves of different durations. Using a combination of field observations and simulated laboratory heatwave experiments, we uncover strong seasonal variation in the performance curves of A. tonsa but not A. hudsonica. This translated to species-specific seasonal patterns of vulnerability to heatwaves, with increased vulnerability in A. hudsonica. 3. By reducing parental stress during simulated heatwaves, seasonal performance curve shifts likely reduced indirect, transgenerational effects of these events on offspring performance in A. tonsa. 4. Our results illustrate how different levels of seasonal variation in thermal performance curves will affect population persistence in a changing climate.

Hair coat of the water deer <I>Hydropotes inermis</I> (Cervidae, Artiodactyla) – a new species in the fauna of Russia

For the first time, the hair cover and hair microstructure of an adult male Hydropotes inermis from the Primorsky region of Russia were studied using light and scanning electron microscopy. The absence of abundant underfur, sparse wool and its weak layering are characteristic of this inhabitant of the temperate monsoon and tropical zones, which does not need an effective thermal protection.The alveolar and lattice medulla of the hair is similar to that of other deer, is well developed, and increases the heat-protective properties of the hair, since seasonal and daily fluctuations in temperature and humidity can be significant. The cuticle pattern is similar to that of deer tribes Alceini and Capreolini. The hair serves as reliable protection for the water deer from mechanical damage when moving through thickets of bushes and grasses along the banks of rivers and swamps in the biotopes that this deer inhabits, which is facilitated by the significant thickness and length of the hairs on the back, sides and thighs. The knotty nature of the hairs protects the deer’s skin from the sharp growths of aquatic and marsh plants.

Skin and hair of the Tibetan Hamster (<i>Urocricetus kamensis</i>, Cricetidae, Rodentia): A comparative morphological analysis

For the first time, using light and scanning electron microscopy, the fine structure of the skin and its derivatives (glands, hairs, whiskers) was studied in adult male and female Tibetan hamsters (Urocricetus kamensis Satunin 1903), a unique species of the subfamily Cricetinae that lives only in the highlands of the Tibetan Plateau. A comparative morphological analysis of the skin, along with features of its similarity with the skin of other hamsters, revealed a number of characteristic features in the Tibetan hamster that contribute to the adaptation of this species to the harsh mountain climate conditions with sharp seasonal and daily temperature fluctuations: abundant subcutaneous fatty tissue, a special hair structure that provides effective heat protection due to a significant change in the volume of inert air in the fur: significant hair density, wavy arrangement of rows of hairs and the profile of the lower sections of the guard hairs. The presence of relatively long and thick guide hairs in the fur serves to protect the coat in rocky habitats. The array of specific skin glands is little compared to other Cricetinae; no mid-ventral and flank glands were found, this being unique for representatives of the subfamily, but this requires confirmation based on more abundant material.

Exploring the LULC dynamics and its relation with land surface temperature variation using split window algorithm: A study of Barasat subdivision, West Bengal, India.

Rapid urban growth in an unplanned way, decreased forest cover and consequential changes in land use in urban and rural areas have become pivotal obstacles for policymakers and urban planners to a great extent. Specifically, in a developing country like India, the repercussions of these changes have generated a substantial alteration in climate in the form of increased land surface temperature (LST), heat islands and associated human health risks. This research was initiated to assess the interrelationship between LST and LULC dynamics using spatial techniques over the Barasat Sub-Division in West Bengal (India). This study encompasses the extraction of LST using satellite images, seasonal variations of LST, the relationship of different land indices (i.e. NDVI, NDBI, NDMI and NDWI) with LST, and hotspot analysis of the landscape to get a comprehensive understanding of LST changes from 1988 to 2023, seasonal patterns, and relationships with LULC dynamics in the study area. The results of this research signify a substantial percentage increase in built-up spaces (51%), a decline in fallow areas (- 73%), relatively higher LST changes (3.41°C) in high-density built-up areas (e.g. Madhyamgram), a positive relationship (e.g. r2 = 0.59) between NDBI and LST, a transition from a cold spot to a hot spot share of 20% and a persisting hot spot of 42% throughout the summer season (1988 to 2023) in the selected landscape. The findings of this study will improve our present knowledge of seasonal fluctuations in land surface temperature (LST) and the variables that influence them. These findings will also draw attention to the growing worries about the fast variations in LST and the climatic and health hazards they pose. It is advised to establish planned urban expansion, efficient land use and land cover (LULC) management laws and encourage green areas that support sustainable development in India's urban surroundings in order to reduce these dangers.

Dual-Mode cellulose acetate@Al2O3/MWCNTs Janus fabric with radiative cooling and solar heating for personal thermal management

Personal thermal management (PTM) textiles with heating and cooling functionalities are highly appealing due to their potential to offer personalized comfort while also contributing to decrease energy consumption. However, most PTM fabrics are static and unable to meet the human body’s thermal comfort needs during seasonal and ambient temperature fluctuations. Herein, this work presents a dual-mode Janus Metafabric to provide radiation cooling and solar heating. The cooling side of Metafabric (cellulose acetate@Al2O3 porous coating) offers high solar reflectance (92.12 %), infrared emissivity (83.22 %), and net cooling power of 55.85 W·m−2. The heating side (multi-walled carbon nanotubes) exhibits a high solar absorption rate (88.4 %). Compared with raw fabric, it can achieve an additional cooling of 4.58 °C and heating of 38.02 °C. In addition, Metafabric also have excellent ultraviolet resistance, wear resistance, and washing properties, making it suitable for practical wearing. By flipping the Janus fabric, it is easy to switch between the cooling and heating modes to adapt to dynamic ambient temperature changes, which have great potential for maintaining human thermal comfort and alleviating the energy crisis.

Wind Rose Analysis of Temperature Variation with Sensor Implantation Technique for Wind Turbine

This study focuses on analysing the impact of seasonal variations in heat on different parts of a "wind energy system," serving as a representative mechanical system. The proposed methodology utilizes wind rose analysis, offering a straightforward means to assess heat transfer effects, applicable to any mechanical system comprising numerous small heat-dissipating components. Furthermore, this work elucidates the correlation between mechanical component performance and heat dissipation impact, providing breakdown alerts for various wind turbine components. Additionally, it analyses the influence of mechanical part temperatures on energy generation, highlighting how high temperatures can indicate component deterioration, such as bearing damage. Notably, the study focuses on wind speeds ranging from 10 to 15 m/s, a typical operational range for wind turbines. By employing wind rose charts and real-time readings, the graded heat dissipating potential of mechanical parts under various wind velocities and weather conditions is determined. Moreover, the study emphasizes the significance of heat transfer analysis in optimizing wind turbine performance, demonstrating how temperature differentials between mechanical components and the environment, along with increased surface area, affect heat transfer. The proposed analysis underscores the importance of considering heat's impact on each mechanical component in tandem with seasonal environmental temperature fluctuations. The wind rose methodology, integrated with sensor implantation, emerges as a cost-effective tool for studying -level heat variances in mechanical systems, enabling the development of heat profiles for future turbine designs and computational fluid dynamics (CFD) analyses. As heat transfer coefficient increases the wind turbine performance decrease. The heat transfer coefficient decreases 14.28% from rainy to winter season and 42.85% from winter to summer season. The wind rose analysis provides valuable insights into wind patterns and characteristics at a specific location, which can inform decision-making in various fields such as energy, construction, environmental management, and safety planning. As the turbine temperature increases the wind velocity decreases. Here it decreases 28 % from rainy to winter season.

Temperature dependence of water and salt transport in concentration gradient batteries: Insight from membrane properties

The performance of concentration gradient batteries (CGBs) based on reverse electrodialysis technology is inevitably influenced by seasonal temperature fluctuations; however, these effects have not been thoroughly investigated. This study explored the temperature dependence of water and salt transport in CGBs using five different membranes over a temperature range of 5–45 °C to elucidate these impacts. The results indicated that the temperature dependence of current efficiency and voltage efficiency in CGBs was respectively controlled by permeation processes (including both water and salt) and membrane resistance. The temperature dependence of mass transfer in these membranes was associated with the characteristics of the species crossing the membrane (such as size) and, more significantly, with membrane properties, including water volume fraction and fixed charge density. Therefore, we proposed that controlling these membrane characteristics can modulate the influence of temperature on mass transfer and CGB performance. This research enhanced our understanding of how temperature affects mass transfer mechanisms in different membranes and provided valuable insights for improving energy conversion in CGBs and other membrane processes.

Modeling the Effects of Temperature and Limiting Nutrients on the Competition of an Invasive Floating Plant, Pontederia crassipes, with Submersed Vegetation in a Shallow Lake.

The potential for a non-native plant species to invade a new habitat depends on broadscale factors such as climate, local factors such as nutrient availability, and the biotic community of the habitat into which the plant species is introduced. We developed a spatially explicit model to assess the risk of expansion of a floating invasive aquatic plant species (FAV), the water hyacinth (Pontederia crassipes), an invader in the United States, beyond its present range. Our model used known data on growth rates and competition with a native submersed aquatic macrophyte (SAV). In particular, the model simulated an invasion into a habitat with a mean annual temperature different from its own growth optimum, in which we also simulated seasonal fluctuations in temperature. Twenty different nutrient concentrations and eight different temperature scenarios, with different mean annual amplitudes of seasonal temperature variation around the mean of the invaded habitat, were simulated. In each case, the ability of the water hyacinth to invade and either exclude or coexist with the native vegetation was determined. As the temperature pattern was changed from tropical towards increasingly cooler temperate levels, the competitive advantage shifted from the tropical FAV to the more temperate SAV, with a wide range in which coexistence occurred. High nutrient concentrations allowed the coexistence of FAV, even at cooler annual temperatures. But even at the highest nutrient concentrations in the model, the FAV was unlikely to persist under the current climates of latitudes in the Southeastern United States above that of Northern Alabama. This result may have some implications for where control efforts need to be concentrated.

Identification of potential landslide in Jianzha county based on InSAR and deep learning

Landslide disasters have characteristics of frequent occurrence, widespread impact, and high destructiveness, posing serious threats to human lives, property, and the ecological environment. Timely and accurate early identification of landslides remains an urgent issue within the disaster prevention field. This study focuses on Jianzha County, Qinghai Province, integrating PS-InSAR, SBAS-InSAR, and optical remote-sensing techniques to delineate potential landslide-prone areas. Utilizing Google Earth imagery and existing landslide datasets, potential landslide points were identified through a deep learning model. Results indicate the following: (1) In Jianzha County, the variation trend of the average surface velocity monitored by PS-InSAR and SBAS-InSAR technology is consistent, and the deformation monitoring results are reliable. (2) Utilizing the deep learning model, 56 potential landslide points were identified, comprising 39 high-risk points and 17 medium-risk points. By integrating the spatial distribution data of historical geological disaster points, 10 out of 13 previously occurred landslide disaster points were found to be located at the identified high-risk landslide points, achieving a detection accuracy of 76.92%. (3) The spatial distribution of landslide points exhibits clustering, with slopes ranging from 10° to 40°, elevations between 15 and 30 m, and slope orientations predominantly toward the northeast. (4) Landslide formation is correlated with seasonal precipitation concentrations and temperature fluctuations. This method can provide a crucial basis for large-scale surface deformation monitoring and early identification of landslide risks.

Saturated dissolved oxygen-driven high-rate and ultrastable partial nitrification in municipal wastewater

Achieving stable and high-rate partial nitrification (PN) remains a worldwide technical conundrum in low-strength mainstream conditions. This study successfully achieved ultrarapid mainstream PN within 8 days under a saturated dissolved oxygen (DO) supply strategy, reaching a record-breaking PN rate of over 1.0 kg N m−3 d−1 treating municipal wastewater. Stable PN was maintained for over 200 days with an ultrahigh nitrite accumulation ratio of 98.5 ± 0.9 %, resilient to seasonal fluctuations in temperature (16.0–25.6 °C) and load (NH4+-N, 40–80 mg N/L). Kinetics revealed a remarkable 159.1-fold increase in the maximum activity ratio of ammonia-oxidizing bacteria (AOB) to nitrite-oxidizing bacteria (NOB). The faster response of AOB to saturated DO stimulated its highest activity difference with NOB, contributing to the AOB (Nitrosomonas oligotropha) boom and the elimination of NOB groups (−99.9 %). Our results highlight the importance of promoting AOB rather than solely focusing on NOB suppression for initiating and stabilizing high-rate mainstream PN.

Effects of seasonal temperature fluctuations and social factors on the transmission of malaria

AIM: To conduct a retrospective analysis of the incidence of malaria episodes in the Astrakhan region from 2002 to 2022 in relation to climatic and social factors in order to provide the evidence for development of effective preventive measures. MATERIAL AND METHODS: An observational study. We performed correlation analysis to study associations between the spread of malaria and climatic and social factors in 2002–2022 in the Astrakhan region. The analysis was based on the data obtained from reporting forms of the Center for Hygiene and Epidemiology in the Astrakhan Region and Rospotrebnadzor in the Astrakhan region. Statistical processing of the data was carried out using Microsoft Office Excel tables (Microsoft, USA) and BioStat Professional 5.8.4. RESULTS: A decrease in the number of malaria cases in the Astrakhan region over the study period was a positive trend, which indicates the importance and effectiveness of measures to combat this serious disease. CONCLUSIONS: It is necessary to continue working in this direction in order to ensure the safety and well-being of the population in relation to the reported imported cases of malaria in the region.

Species-specific differences and temperature-dependence of Na+/K+-ATPase in freshwater mussels Anodonta anatina and Unio tumidus (Bivalvia: Unionidae)

The predicted global warming of surface waters can be challenging to aquatic ectotherms like freshwater mussels. Especially animals in northern temperate latitudes may face and physiologically acclimate to significant stress from seasonal temperature fluctuations. Na+/K+-ATPase enzyme is one of the key mechanisms that allow mussels to cope with changing water temperatures. This enzyme plays a major role in osmoregulation, energy control, ion balance, metabolite transport and electrical excitability. Here, we experimentally studied the effects of temperature on Na+/K+-ATPase activity of gills in two freshwater mussel species, Anodonta anatina and Unio tumidus. The study animals were acclimated to three ambient temperatures (+4, +14, +24 °C) and Na+/K+-ATPase activity was measured at those temperatures for each acclimation group. Both species had their highest gill Na+/K+-ATPase activity at the highest acclimation temperature. Na+/K+-ATPase activity of gills exhibited species-specific differences, and was higher in A. anatina than U. tumidus in all test groups at all test temperatures. Temperature dependence of Na+/K+-ATPase was confirmed in both species, being highest at temperatures between +4 and + 14 °C when Q10 values in the acclimation groups varied between 5.06 and 6.71. Our results underline the importance of Na+/K+-ATPase of gills for the freshwater mussels in warming waters. Because Na+/K+-ATPase is the driving force behind ciliary motion, our results also suggest that in warming waters A. anatina may be more tolerant at sustaining vigorous ciliary action (associated with elevated respiration rates and filter-feeding) than U. tumidus. Overall, our results indicate great flexibility of the mussel's ecophysiological characteristics as response to changing conditions.

Soil salinity regulates spatial-temporal heterogeneity of seed germination and seedbank persistence of an annual diaspore-trimorphic halophyte in northern China

Background and aimsSeed heteromorphism is a plant strategy that an individual plant produces two or more distinct types of diaspores, which have diverse morphology, dispersal ability, ecological functions and different effects on plant life history traits. The aim of this study was to test the effects of seasonal soil salinity and burial depth on the dynamics of dormancy/germination and persistence/depletion of buried trimorphic diaspores of a desert annual halophyte Atriplex centralasiatica.MethodsWe investigated the effects of salinity and seasonal fluctuations of temperature on germination, recovery of germination and mortality of types A, B, C diaspores of A. centralasiatica in the laboratory and buried diaspores in situ at four soil salinities and three depths. Diaspores were collected monthly from the seedbank from December 2016 to November 2018, and the number of viable diaspores remaining (not depleted) and their germinability were determined.ResultsNon-dormant type A diaspores were depleted in the low salinity “window” in the first year. Dormant diaspore types B and C germinated to high percentages at 0.3 and 0.1 mol L-1 soil salinity, respectively. High salinity and shallow burial delayed depletion of diaspore types B and C. High salinity delayed depletion time of the three diaspore types and delayed dormancy release of types B and C diaspores from autumn to spring. Soil salinity modified the response of diaspores in the seedbank by delaying seed dormancy release in autum and winter and by providing a low-salt concentration window for germination of non-dormant diaspores in spring and early summer.ConclusionsBuried trimorphic diaspores of annual desert halophyte A. centralasiatica exhibited diverse dormancy/germination behavior in respond to seasonal soil salinity fluctuation. Prolonging persistence of the seedbank and delaying depletion of diaspores under salt stress in situ primarily is due to inhibition of dormancy-break. The differences in dormancy/germination and seed persistence in the soil seedbank may be a bet-hadging strategy adapted to stressful temporal and spatial heterogeneity, and allows A. centralasiatica to persist in the unpredictable cold desert enevironment.

Temperature and body size affect movement of juvenile Atlantic cod (Gadus morhua) and saithe (Pollachius virens) at nearshore nurseries.

Seasonal migrations of marine fish between shallow summer feeding habitats and deep overwintering grounds are driven by fluctuations in the biotic and abiotic environment as well as by changes in the internal state. Ontogenetic shifts in physiology and metabolism affect the response to environmental drivers and may lead to changes in migration timing and propensity. In this study, we investigated the effect of temperature and body size on migration timing and depth distribution in acoustically tagged Atlantic cod, Gadus morhua, and saithe, Pollachius virens, during the period of seasonal migration from shallow summer habitats. The results from our study revealed a wide range of horizontal and vertical distribution of age 1 and 2 G. morhua within the fjord. Larger G. morhua inhabited deeper, cooler waters than smaller juveniles, likely reflecting size-dependent thermal preferences and predation pressure. Conversely, juvenile P. virens occupied primarily shallow waters close to land. The variation in depth distribution of G. morhua was mainly explained by body size and not, against our predictions, by water temperature. Conversely, the dispersal from the in-fjord habitats occurred when water temperatures were high, suggesting that seasonal temperature fluctuations can trigger the migration timing of P. virens and larger G. morhua from summer habitats. Partial migration of small juvenile G. morhua from in-fjord foraging grounds, likely influenced by individual body condition, suggested seasonal migration as a flexible strategy that individuals may use to reduce predation and energetic expenditure. Predation mortality rates of tagged juveniles were higher than previously suggested and are the first robust predation mortality rates for juvenile G. morhua and P. virens estimated based on acoustic transmitters with acidity sensors. The results have relevance for climate-informed marine spatial planning as under the scenario of increasing ocean temperatures, increasing summer temperatures may reduce the juveniles' resource utilization in the shallow summer nurseries, resulting in lower growth rates, increased predation pressure, and lower chances of juvenile winter survival.

Assessment of Carbon Sink and Carbon Flux in Forest Ecosystems: Instrumentation and the Influence of Seasonal Changes

Accurate measurement and estimation of forest carbon sinks and fluxes are essential for developing effective national and global climate strategies aimed at reducing atmospheric carbon concentrations and mitigating climate change. Various errors arise during forest monitoring, especially measurement instability due to seasonal variations, which require to be adequately addressed in forest ecosystem research and applications. Seasonal fluctuations in temperature, precipitation, aerosols, and solar radiation can significantly impact the physical observations of mapping equipment or platforms, thereby reducing the data’s accuracy. Here, we review the technologies and equipment used for monitoring forest carbon sinks and carbon fluxes across different remote sensing platforms, including ground-based, airborne, and spaceborne remote sensing. We further investigate the uncertainties introduced by seasonal variations to the observing equipment, compare the strengths and weaknesses of various monitoring technologies, and propose the corresponding solutions and recommendations. We aim to gain a comprehensive understanding of the impact of seasonal variations on the accuracy of forest map data, thereby improving the accuracy of forest carbon sinks and fluxes.

Hair Coat of the Water Deer Hydropotes inermis (Cervidae, Artiodactyla), a New Species in the Russian Fauna.

The hair coat and hair microstructure of an adult male Hydropotes inermis from the Primorsky Krai of Russia were studied for the first time by light and scanning electron microscopy. Lack of abundant underfur, sparse hair, and a weak layering are characteristic of the species, which inhabits the temperate monsoon and tropical zones and does not need an efficient thermal protection. An alveolar and lattice medulla of the hair is similar to that of other deer, is well developed, and increases the heat-protective properties of the hair because seasonal and daily fluctuations in temperature and humidity can be significant. The cuticle pattern is similar to that of the deer tribes Alceini and Capreolini. The hair thickness and length are substantial on the back, sides, and thighs, and the coat thus provides reliable protection from mechanical damage when the water deer moves through thickets of bushes and grasses along riverbanks and swamps in its habitats. A knotty nature of hairs protects the skin from sharp outgrowths of aquatic and marsh plants.

Strong acclimation effect of temperature and humidity on heat tolerance of the Arctic collembolan Megaphorura arctica.

The Arctic is a highly variable environment in which extreme daily and seasonal temperature fluctuations can occur. With climate change, an increase in the occurrence of extreme high temperatures and drought events is expected. While the effects of cold and dehydration stress on polar arthropods are well studied in combination, little is known about how these species respond to the combined effects of heat and dehydration stress. In this paper, we investigated how the heat tolerance of the Arctic collembola Megaphorura arctica is affected by combinations of different temperature and humidity acclimation regimes under controlled laboratory conditions. The effect of acclimation temperature was complex and highly dependent on both acclimation time and temperature, and was found to have a positive, negative or no effect depending on experimental conditions. Further, we found marked effects of the interaction between temperature and humidity on heat tolerance, with lower humidity severely decreasing heat tolerance when the acclimation temperature was increased. This effect was more pronounced with increasing acclimation time. Lastly, the effect of acclimation on heat tolerance under a fluctuating temperature regime was dependent on acclimation temperature and time, as well as humidity levels. Together, these results show that thermal acclimation alone has moderate or no effect on heat tolerance, but that drought events, likely to be more frequent in the future, in combination with high temperature stress can have large negative impacts on heat tolerance of some Arctic arthropods.

Local adaptation of trophic strategy determined the tolerance of coral Galaxea fascicularis to environmental fluctuations

The escalation of global change has resulted in heightened frequencies and intensities of environmental fluctuations within coral reef ecosystems. Corals originating from marginal reefs have potentially enhanced their adaptive capabilities in response to these environmental variations through processes of local adaptation. However, the intricate mechanisms driving this phenomenon remain a subject of limited investigation. This study aimed to investigate how corals in Luhuitou reef, a representative relatively high-latitude reef in China, adapt to seasonal fluctuations in seawater temperature and light availability. We conducted a 190-day plantation experiment with the widespread species, Galaxea fascicularis, in Luhuitou local, and from Meiji reef, a typical offshore tropical reef, to Luhuitou as comparison. Drawing upon insights from physiological adaptations, we focused on fatty acid (FA) profiles to unravel the trophic strategies of G. fascicularis to cope with environmental fluctuations from two origins. Our main findings are threefold: 1) Native corals exhibited a stronger physiological resilience compared to those transplanted from Meiji. 2) Corals from both origins consumed large quantities of energy reserves in winter, during which FA profiles of local corals altered, while the change of FA profiles of corals from Meiji was probably due to the excessive consumption of saturated fatty acid (SFA). 3) The better resilience of native corals is related to high levels of functional polyunsaturated fatty acid (PUFA), while insufficient nutrient reserves, possibly due to weak heterotrophic ability, result in the obstruction of the synthesis pathway of PUFA for corals from Meiji, leading to their intolerance to environmental changes. Consequently, we suggest that the tolerance of G. fascicularis to environmental fluctuations is determined by their local adapted trophic strategies. Furthermore, our findings underscore the notion that the rapid adaptation of relatively high-latitude corals to seasonal environmental fluctuations might not be readily attainable for their tropical counterparts within a brief timeframe.

Temporal and Spatial Dynamics of Vibrio harveyi: An Environmental Parameter Correlation Investigation in a 4-Metre-Deep Dicentrarchus labrax Aquaculture Tank.

Nowadays, European seabass (Dicentrarchus labrax) aquaculture is undergoing a significant expansion. Nevertheless, the aquaculture industry is plagued by vibriosis. The spatial and temporal dynamics of Vibrio harveyi were studied on a European seabass farm in northern France during seven months of 2022. Concrete specimens were suspended and water was pumped from different depths (0.3 m, 2.15 m and 4 m deep), providing insights into the biofilm and planktonic V. harveyi dynamics. The abundances of V. harveyi, in the biofilm and free-living forms, were positively correlated. The water parameters revealed seasonal fluctuations in temperature, pH, and salinity, with no significant differences observed across the water column. Quantification of V. harveyi revealed no significant differences between depths, but seasonality, with peak abundances observed in August, correlated with temperature increases. Principal component analysis identified temperature as a primary driver, but also additional parameters, such as salinity and pH. Vibriosis occurred during the sampling period, providing valuable insights into the conditions before, during, and after the outbreaks. This study underscores the importance of understanding V. harveyi behaviour in aquaculture, particularly in the context of global warming, for effective disease management and sustainable practices.

Shark critical life stage vulnerability to monthly temperature variations under climate change

In a 10-month experimental study, we assessed the combined impact of warming and acidification on critical life stages of small-spotted catshark (Scyliorhinus canicula). Using recently developed frameworks, we disentangled individual and group responses to two climate scenarios projected for 2100 (SSP2-4.5: Middle of the road and SSP5-8.5: Fossil-fueled Development). Seasonal temperature fluctuations revealed the acute vulnerability of embryos to summer temperatures, with hatching success ranging from 82% for the control and SSP2-4.5 treatments to only 11% for the SSP5-8.5 treatment. The death of embryos was preceded by distinct individual growth trajectories between the treatments, and also revealed inter-individual variations within treatments. Embryos with the lowest hatching success had lower yolk consumption rates, and growth rates associated with a lower energy assimilation, and almost all of them failed to transition to internal gills. Within 6 months after hatching, no additional mortality was observed due to cooler temperatures.