High Water Levels Research Articles

British surveillance of postwar Soviet radio jamming: US–UK intelligence relations and interference detection at BBC Tatsfield, 1948-1949

ABSTRACT Following World War II, the BBC, better known for radio programme broadcasts, continued its long-standing work of radio spectrum surveillance at the specialized receiving and measurement facility located at Tatsfield. Both before and after Soviet jamming of US and British Russian-language broadcasts escalated in April 1949, Tatsfield catalogued the technical characteristics of jamming signals. BBC engineers, experienced in interpreting types and sources of radio interference, issued fortnightly summaries with interpretations of these technical observations. US intelligence agencies knew of Tatsfield’s findings, but differing perspectives in Washington and London resulted in divergent responses to the technical intelligence data. With rising tensions in wider Anglo-American intelligence relations, fueled by the Soviet weapons program and security breaches, such differences presaged separate approaches to Soviet communications threats. US agencies received greatly increased funding, while the BBC’s budget struggles persisted. Even so, interference detection was a high-water mark in Britain’s early Cold War intelligence work.

Developmental plasticity to desiccation risk in tadpoles of a tropical inselberg specialist

Developmental plasticity evolves in heterogeneous environmental conditions as long as individuals can accurately perceive them. A paradigmatic example of developmental plasticity is the ability of amphibian larvae to alter growth and development in response to the risk of pond drying. Such responses are often found in amphibian species breeding in highly dynamic water bodies with high desiccation risk. The inselbergs of the Guianan Shield are rocky outcrops with extremely high and fluctuating temperatures and a marked seasonality in precipitation. During the rainy season, eroded depressions form precipitation-dependent pools with a high and variable risk of desiccation within the timeframe of a few days. The frog Leptodactylus lithonaetes specializes in breeding in this extreme environment, and its tadpoles are thus forced to cope with desiccation risk by adjusting their developmental trajectories and physiological performance. We experimentally assessed the effect of different levels of desiccation risk, under controlled temperature conditions, on developmental rate, growth, and temperature-dependent locomotor performance in tadpoles of Leptodactylus lithonaetes. We did not find an effect of desiccation risk on developmental rate, but under simulated drying conditions, tadpoles showed larger body size, greater body mass, and enhanced locomotor performance compared to constant (high or low) water levels. These results suggest that drying pools offer cues that trigger developmental and behavioral changes in these tadpoles, enabling them to enhance growth over a short time span without accelerating development. We discuss the potential compensatory mechanisms behind these responses and highlight the need for further investigations in species with semiterrestrial life histories in extreme environments.

Natural disturbance allows multiple anuran taxa to persist in a dynamic wetland complex

AbstractThe maintenance of biological diversity is frequently enhanced in a heterogenous landscape by some level of disturbance. Thus, when a landscape becomes stabilized and homogenized through the spread of an invasive plant species, there may be consequences for native biodiversity, particularly for those biotas that depend on the pre‐existing, natural disturbance regime of that landscape. At Long Point, Ontario, Canada, a sandspit in Lake Erie, the community of anuran amphibians experienced the co‐incidence of 2 major disturbance events, 1 anthropogenic and 1 natural: an intervention to remove the invasive form of the common reed (Phragmites australis australis) and a spate of extensive dune washouts caused by high water levels and storms. As a result of the unequal distribution of disturbance in the landscape, different areas were affected by only the dune washouts, only the common reed treatment, both disturbances, or neither disturbance. From May to August 2021, we explored how the disturbances affected the resident frog and toad species habitat associations in the 4 different disturbance conditions in the landscape. By means of minnow traps, acoustic surveys, and visual surveys, we determined that the dune washouts had a greater influence on resident anurans than the common reed treatment. Ranid frogs (Ranidae) tended to inhabit non‐washout sites, whereas Fowler's toads (Anaxyrus fowleri) congregated in the newly formed, sand flats and shallow, de‐vegetated pools resulting from the washouts. Neither ranid frogs nor Fowler's toads demonstrated avoidance of the sites affected by the herbicide treatment and mechanical rollover of the common reed. This evidence of species sorting, which enables multiple species to persist in a dynamic and heterogeneous landscape, suggests that wildlife management in aid of threatened species recovery may find success by encouraging natural disturbance regimes in dynamic landscapes. Future management endeavors should consider refraining from complete dune stabilization in these landscapes to allow the natural washouts to occur at a higher frequency, while ensuring the continued effectiveness of the invasive common reed eradication.

Centrifuge modelling on seismic failure of MSW landfills with high water level

Landfill failure threatens the safety of surrounding cities and causes soil and water pollution. High water levels can usually spur landfill failure. With the presence of earthquake, landfill instability is triggered in a greater possibility. However, the dynamic response and failure mechanism of landfills with high water level subjected to earthquakes are not yet clearly understood, and relevant experimental studies are quite scarce. This study includes a series of seismic centrifuge tests to investigate the seismic response of the landfill at different water levels. An improved method is proposed to prepare synthetic municipal solid wastes (MSWs) with similar static-dynamic properties to the actual MSWs. The failure and evolution mechanism of landfills with high water levels induced by the earthquake is revealed. Significant transitions are observed in the dynamic response of deformation, acceleration, and pore-water pressure as the water level changes. With the rise of water level, the settlement at the top of the landfill decreases first and then increases, while the horizontal displacement at the toe increases slowly, followed by a sudden drop; the acceleration amplification coefficient in the middle of the landfill increases first and then decreases; the dynamic pore-water pressure gradually decreases from positive to negative, but oscillates at the moderate water level. Three failure criteria and a hydro-earthquake coupled failure limit are proposed to demonstrate the combined effect of water level and earthquake on landfill stability. The test results provide a basis to establish seismic failure standards for landfills with different water levels and guide the seismic instability design of landfills with high water level.

Research on Response Characteristics of GPR Method for Detecting Phreatic Lines in Embankments

The excessive elevation of the phreatic lines under continuous high-water levels is the cause of many dangerous situations in embankments. Therefore, accurately understanding the dynamic changes in the infiltration characteristics of embankments is of great significance for judging and evaluating the stability of engineering. This study conducted indoor model experiments and used ground penetrating radar to detect the phreatic lines of soil. By comparing the radar detection results with the measured position of the phreatic lines, it was determined that the phreatic lines appeared as a continuous strong reflection surface with similar shapes in the radargram, and the reflection below the reflection surface became weaker. Through time-domain analysis of the single waveform at different time points, it was found that the amplitude of the reflected wave at the saturation line was larger, and the energy attenuation below the saturation line was faster, resulting in a rapid decrease in amplitude; perform Fourier transform on a single channel signal to obtain a spectrogram, and perform frequency domain analysis on it. The main frequency is around 600MHz, and the second main frequency is around 900MHz. As the saturation line rises, the main frequency gradually shifts towards lower frequencies.

Environmental behaviour of iron and steel slags in coastal settings

Iron and steel slags have a long history of both disposal and beneficial use in the coastal zone. Despite the large volumes of slag deposited, comprehensive assessments of potential risks associated with metal(loid) leaching from iron and steel by-products are rare for coastal systems. This study provides a national-scale overview of the 14 known slag deposits in the coastal environment of Great Britain (those within 100 m of the mean high-water mark), comprising geochemical characterisation and leaching test data (using both low and high ionic strength waters) to assess potential leaching risks. The seaward facing length of slag deposits totalled at least 76 km, and are predominantly composed of blast furnace (iron-making) slags from the early to mid-20th Century. Some of these form tidal barriers and formal coastal defence structures, but larger deposits are associated with historical coastal disposal in many former areas of iron and steel production, notably the Cumbrian coast of England. Slag deposits are dominated by melilite phases (e.g. gehlenite), with evidence of secondary mineral formation (e.g. gypsum, calcite) indicative of weathering. Leaching tests typically show lower element (e.g. Ba, V, Cr, Fe) release under seawater leaching scenarios compared to deionised water, largely ascribable to the pH buffering provided by the former. Only Mn and Mo showed elevated leaching concentrations in seawater treatments, though at modest levels (<3 mg/L and 0.01 mg/L, respectively). No significant leaching of potentially ecotoxic elements such as Cr and V (mean leachate concentrations <0.006 mg/L for both) were apparent in seawater, which micro-X-Ray Absorption Near Edge Structure (μXANES) analysis show are both present in slags in low valence (and low toxicity) forms. Although there may be physical hazards posed by extensive erosion of deposits in high-energy coastlines, the data suggest seawater leaching of coastal iron and steel slags in the UK is likely to pose minimal environmental risk.

Differences in environmental microbial community responses under rice-crab co-culture and crab monoculture models under cyanobacterial bloom

Cyanobacterial blooms (CBs) present significant challenges to Chinese mitten crab (CMC) culture, posing hazards to the aquatic microbial ecology. However, the current focus on the microbial ecological changes within the CMC culture system under the influence of CBs is somewhat insufficient. There’s an urgent need to analyze the microbial ecosystem of the CMC culture system under CBs. This study employed 16S rRNA gene amplicon sequencing to investigate the dynamics of the environmental microbial community in both the rice-crab co-culture (RC) and crab monoculture (CM) models. The results revealed that cyanobacteria reached high levels in the CM water in July, while they began to increase in the RC water in August. Notably, OTU147 (uncultured bacterium g_Planktothrix NIVA-CYA 15), identified as the dominant taxon associated with CBs, showed a significant linear relationship with TP, NO2−-N, and the N:P ratio. TP, TN, NO2−-N, and CODMn had a more pronounced impact on the structure of bacterial communities and cyanobacterial taxa in the water. The bacterial community structure involved in carbon metabolism displayed temporal succession in the water. The co-occurrence network of the bacterial community primarily consisted of Chloroflexi, Proteobacteria, and Firnicutes in the sediment, and Actinobacteria, Proteobacteria, Chloroflexi, and Bacteroidota in the water. In contrast, the co-occurrence network included different peripheral species in the sediment and water. Keystone species were predominantly represented by OTU22 (uncultured actinobacterium g_ hgcI clade) and OTU12 (uncultured Opitutae bacterium g_ norank) in the RC water, and by OTU25 (uncultured bacterium g_ Limnohabitans) in the CM water. TP, TN, NO2−-N, and CODMn were identified as the primary environmental factors influencing these keystone taxa within the culture water. In conclusion, this study on the microbial ecology of the CMC culture system under the influence of CBs provides valuable insights that can be instrumental in subsequent management efforts.

Guaranteed minimum withdrawal benefits with high-water mark fee structure.

The Guaranteed Minimum Withdrawal Benefit (GMWB), an adjunct incorporated within variable annuities, commits to reimbursing the entire initial investment regardless of the performance of the underlying funds. While extensive research exists in financial and actuarial literature regarding the modeling and valuation techniques of GMWBs, much of it is founded on a static fee structure. Our study introduces an innovative fee structure based on the high-water mark (HWM) principle and a regime-switch jump-diffusion model for the pricing of GMWBs, employing numerical solutions through the Monte Carlo method for solving the stochastic differential equation (SDE). Furthermore, a companion piece of research addresses the risk management of GMWBs within the same analytical framework as the pricing component, an aspect that has received limited attention in the existing literature. In assessing the necessary capital reserves for unforeseen losses, our methodology involves the computation of two risk metrics associated with the tail distribution of net liability from the insurer's perspective, Value-at-Risk (VaR) and Conditional-Tail-Expectation (CTE). Comprehensive numerical results and sensitivity analyses are also provided.

Drivers of dune formation control ecosystem function and response to disturbance in a barrier island system.

Barrier islands are landscape features that protect coastlines by reducing wave energy and erosion. Quantifying vegetation-topographic interactions between adjacent habitats are essential for predicting long-term island response and resilience to sea-level rise and disturbance. To understand the effects of dune dynamics on adjacent interior island ecosystem processes, we quantified how sediment availability and previous disturbance regime interact with vegetation to influence dune building and ease of seawater and sediment movement into the island interior on two US mid-Atlantic coast barrier islands. We conducted field surveys of sediment accretion, vegetative cover, and soil characteristics in dune and swale habitats. Digital elevation models provided assessment of water flow resistance from the mean high water mark into the island interior. We found that geographic location impacted sediment accretion rates and Panicum amarum (a species increasing in abundance over time in the Virginia barrier islands) accreted sediment at a significantly lower rate compared to other dune grasses. Dune elevation impacted the ease of seawater flow into the island interior, altering soil chlorides, annual net primary productivity, and soil carbon and nitrogen. Our work demonstrates the importance of incorporating biological processes and cross-island connectivity into future scenario modeling and predictions of rising sea-levels and increased disturbance.

Temporal and spatial variation of typhoon-induced surges and the impact of rainfall in a tidal river

The Huangpu River, which flows into the Yangtze Estuary, runs through Shanghai Municipality in China. During the flood season, typhoon-induced surges result in extremely high water levels in the Huangpu River, which is the main factor threatening flood control safety in Shanghai. Based on observations of water levels at three stations along the Huangpu River from 2008 to 2021, together with wind and rainfall, this paper investigates: the trends of the annual highest storm surges; the differences in periodic variation and magnitude of surges during the spring-neap cycle; the longitudinal variation of surges; and the impact of rainfall. The results show that the annual highest surges at three stations all show a significant increasing trend, which is caused by the increasing wind speed, and the intensity and duration of rainfall during typhoon events, induced by the increasing frequency of landfall and close-to-YE (Yangtze Estuary) typhoon events, and strong and very strong typhoon events. The periodic variation and magnitude of surges show clear differences during the spring-neap cycle, resulting from the largest nonlinear surge-tide interaction during spring tide and the smallest during neap tide. Heavy rainfall can reduce the probability of 6–7 h and 2.7–3.3 h periods, and change the phase of the periodic variation, inducing partial main peaks and maximum surges during ebb or low tide. The longitudinal variation of storm surge along the Huangpu River can be divided into three types: decreasing upstream, first increasing then decreasing, and increasing upstream. Heavy and long-duration rainfall increases the water discharge from the basin to the river, amplifying the surge, with the largest impact in the upper reach and the smallest in the lower reach, which is the main factor inducing the latter two types, particularly the third type.

Responses of ancient reservoir sediments to water level fluctuations, human activity and climatic changes over the past ∼700 yr in Guizhou Province, southwestern China

Knowledge of the responses of reservoir ecosystems to anthropogenic and climatic impacts on multi-centennial timescales is relatively poor, but is crucial for the management of numerous reservoirs in China. In this study, the history of an ancient reservoir system was reconstructed for the last ∼ 700 yr based on multiple dating methods (210Pb, 137Cs, and 14C) and geochemical data (e.g., the mass accumulation rates, loss-on-ignition values, total organic carbon, total nitrogen, total phosphorus contents, and stable carbon isotope ratios of organic matter) obtained for sediment cores from Gongqing Reservoir in Guizhou Province, southwestern China. Combined with historical literature and regional climatic records, the response of the aquatic ecosystem in Gongqing Reservoir to water level fluctuations, anthropogenic activity, and climatic changes during the last ∼ 700 yr was assessed. The results suggest that dramatic changes in the water level due to dam heightening in 1950 s significantly changed the aquatic ecosystem of Gongqing Reservoir. During periods of low water levels (average water depth = 1–2 m; 1345–1957 CE), aquatic macrophytes contributed more to the sedimentary organic matter, whereas phytoplankton increasingly contributed more during periods of high water levels (∼5 m; 1957–2020 CE). During the late stage (1700–1957 CE) of low water levels, the reservoir ecosystem was significantly affected by human activities. Combined with regional geological and historical records, we consider that increased population and enhanced human activities have markedly affected vegetation conditions in western Guizhou Province since ∼ 1700 CE. After 1957 CE, anthropogenic activities were key in affecting the aquatic ecosystem of Gongqing Reservoir. Especially in the last decade, large housing developments and enhanced agricultural activities in the watershed have led to enhanced catchment erosion and transport of more nutrients into the reservoir, thus promoting the algae productivity. These results provide new insights into how reservoir ecosystems respond to water level fluctuations, anthropogenic activity and climatic changes on multi-centennial timescales.

Particulate and water-mobilizable phosphorus from a watershed with a plain river network contributes equal amounts of algal available phosphorus to its downstream lake

This research was designed to estimate the contributions of phosphorus (P) in different factions from an upstream plain river network to algal growth in a downstream shallow eutrophic lake, Taihu Lake, in China. During three flow regimes, the P fractions in multiple phases (particulate, colloidal and dissolved phases) and their algal availabilities were assessed via bioassays with Dolichospermum flos-aquae as the test organism. The P partitioning patterns among multiple phases were strongly affected by the concentration of total suspended solids (TSS) that changed with the river flow regime, with stronger disturbance of sediments at lower water levels (low flow) and weaker disturbance of sediments at higher water levels (high flow) in the plain river network. The median TSS concentration across the river network decreased from 157.4 mg/L during low flow to 31.8 mg/L during high flow, and the median particulate P concentration decreased from 0.132 mg/L to 0.093 mg/L. The particulate P contributed equally to the amount of algal available P (AAP) as did the water-mobilizable P (colloidal plus dissolved phase) in the rivers flowing into Taihu Lake. The annual average concentrations of particulate algal available P (P-AAP), colloidal algal available P (C-AAP) and dissolved algal available P (D-AAP) were estimated to be 0.032 mg/L, 0.012 mg/L and 0.019 mg/L, respectively, during 2012–2018, accounting for 50.8 %, 19.0 % and 30.2 %, respectively, of the total AAP. At the watershed scale, controlling P drainage from downstream urbanized areas should be emphasized. Additionally, controlling sediment resuspension or reducing the TSS concentration in the inflowing rivers is important for decreasing the particulate P flux to downstream lakes.

Nutritional profiles of Middle Eastern dishes and composition

The study examined 27 traditional Middle Eastern/Kuwaiti dishes, primarily meat, chicken, and fish-based, to assess their taste and nutritional content. The evaluation included protein, moisture, carbohydrates, ash, fat, energy, dietary fiber, 11 vitamins, 8 minerals, and 3 sugars. Certain dishes displayed high levels of protein, fat, energy, water, carbohydrates, and dietary fiber. For instance, Marag laham and Majbous dajaj stood out for their high protein, fat, and energy content. Additionally, Marag laham and Marag dajaj exhibited high water content of 63.55% and 69.42% respectively for the meat and chicken section, while Majbous laham and Majbous dajaj had elevated carbohydrate levels due to the rice (27.52%). Notably, Turkey and Arabic meat shawarma had the highest fat energy with Arabic meat shawerma energy calculated at 400.91 kcal due to its total fat content (31.74%). The study concludes that using standard recipes for common meals can facilitate the collection of global and regional food composition data, which can be integrated into global food composition databases for diverse ethnic communities. Overall, the research highlights the importance of considering both taste and nutrition when making food choices and supports making informed dietary decisions based on comprehensive nutritional information

Wonorejo dam operation and storage analysis against climate change

Climate change affecting rain intensity within catchment and increase the potential hydrometeorology disasters. Wonorejo Reservoir as a multipurpose dam requires an operational plan and water allocation to fulfill downstream needs, such as irrigation, hydropower, microhydropower, domestic industry uses and flood control. Wonorejo Dam is a backfill type dam with High Water Level (HWL) elevation is +183.00 mSHVP and Low Water Level (LWL) elevation is +141.00 mSHVP, Total storage capacity Wonorejo Reservoir is 109.118 million m3 (2021) or 89.4% from initial total storage capacity (2000), in 2050 predicted sediment volume increase to 17.73 million m3 or 17.6% reservoir capacity and 2050 capacity volume is 100,585 million m3 or 82.4% from initial total storage capacity. Annual Reservoir Operation Plan and Annual Water Allocation Plan for Wonorejo Reservoir in 2022/2023 as water services December 2022 to November 2023 periode, Wonorejo Reservoir elevation at the end of May 2023 reaches HWL and lowest water elevation is +162.64 mSHVP in the first week of November 2023.

Physical Modelling Tests With Flexible Woody Vegetation Mimics

Riparian forests in front of dikes can dampen incoming waves and thereby contribute to flood safety. In real-scale flume experiments with live pollard willow trees (forming a 40-m-long forest), it was observed that during storm conditions, a maximum reduction of 20 % in incoming wave height could be achieved (van Wesenbeeck, et al., 2022). Notably, this amount of wave damping occurred at a water depth of 3 meters, aligning with the section of the trees with the maximum frontal-surface area. For a larger water depth, measured wave damping however declined. This is potentially partly caused by the natural tapering form of the trees. Typically, trees are characterized by smaller branch diameters and more flexible branches higher up in the canopy (McMahon &amp; Kronauer, 1976); and flexible vegetation mimics are known to dampen less than rigid mimics due to motion (Van Veelen, T, Reeve, &amp; Karunarathna, 2020). Hence, both the frontal-surface area and branch rigidity decrease along the height of the willow trees, potentially leading to less wave damping by the forest when subject to large waves at higher water levels.

Enhancing Bean (Phaseolus vulgaris L.) Resilience: Unveiling the Role of Halopriming against Saltwater Stress

Common bean (Phaseolus vulgaris L.), one of the most important cultivated legumes, requires a high level of water. It is included among the most sensitive species to climate change; drought and salinity cause a reduction in photosynthesis, metabolic and enzymatic alterations, and oxidative stress. To improve crop tolerance to salt, seed priming and acclimation can be useful tools. To test the salt tolerance of beans, a preliminary screening was undertaken on four cultivars of P. vulgaris (Black Turtle, Cargamanto, Bola Roja, Borlotto) by exposing the seeds to different levels of salinity. The salt-sensitive cultivar Borlotto was chosen for experimental greenhouse trials to study the effects of halopriming and acclimation. Primed and non-primed seeds were sown in non-saline soil and acclimated for 2 weeks; then, the plants were watered with non-saline and saline solutions for 4 weeks. At the end of this growth period, the primed plants showed a marked increase in salt stress tolerance, improving the chlorophyll content, phenolic compounds, and many enzymes’ activities, in turn reducing the effect of salt on growth and fruit production compared to the non-primed controls. In conclusion, halopriming can be considered a useful tool to enhance salinity tolerance in beans and other salt-sensitive crops.

Liquefaction characteristics of aging earth dam body by dynamic centrifugal model test

Earth dams have been damaged or even collapsed owing to earthquake liquefaction. Although a liquefied foundation is a major factor affecting the safety of earth dams, the damage caused by the liquefaction of the dam body itself cannot be ignored, particularly for aged earth dams. However, in the presence of high water levels, liquefaction of the dam body cannot be considered solely in terms of the seismic load. Consequently, in this study we used dynamic centrifuge tests and numerical analysis to simulate the liquefaction process of an earth dam body under high water levels and analyzed the damage mechanism. The aging dam body, which can be easily liquefied, was simulated by controlling the density of the dam body, the low-density dam body exhibiting greater acceleration-amplification characteristics and displacement. Liquefaction was evident in the contact area between the slope and water level, with segmental settlement occurring. Through numerical analysis, it was evident that the core area accumulated considerable plastic deformation, and the sliding damage extended from the water contact surface to the dam toe. This study could compensate for the dearth of liquefaction model experiments of earth dams, providing a necessary reference for the seismic reinforcement of earth dams.

Impact of Water Level Variation on Mechanical Properties of Porous Concrete

This paper investigates porous concrete and the influence of water level variations and porosity on the mechanical, physical, and hydraulic properties of porous concrete. The effect of different void percentages and various water levels on the properties of porous concrete was studied. Fabricated specimens with targeted porosities of 20% and 25% were subjected to a series of tests to evaluate their compressive strength, hydraulic conductivity (permeability), and porosity. The permeability of the specimens was assessed using a falling head permeameter to ensure effective water percolation. Porosity was quantified through a volumetric method, providing insights into void content. Both cubical and cylindrical specimens were used for all tests, along with compression tests under both air-dried and oven-dried conditions. The results showed that the maximum compressive strength occurred under oven-dried conditions for both cubical (7.05 MPa, 5.58 MPa) and cylindrical (8.36 MPa, 4.81 MPa) specimens, with 20% and 25% porosities, respectively. The compressive strength was found to be low in air-dried samples and increased with higher water levels, peaking at the 40% water level. Furthermore, the porosity exhibited a significant correlation with the reduction in density, affecting the mechanical properties. For the cylindrical and cubical samples, the dry density decreased by 16.03 kg/m3 and 20.85 kg/m3 and the permeability increased by 0.41 mm/s and 0.84 mm/s, respectively, for every 1% increase in porosity. The results showcased the effect of water level variation on porous concrete properties as well as its promising ability to infiltrate water. This promotes the development of sustainable pavement systems by minimizing surface runoff and aiding groundwater recharge.

The role of phenotypic plasticity and corticosterone in coping with pond drying conditions in yellow-bellied toad (Bombina variegata, Linnaeus 1758) tadpoles.

Amphibian larvae inhabiting temporary ponds often exhibit the capacity to accelerate development and undergo metamorphosis in challenging conditions like desiccation. However, not all species exhibit this ability, the yellow-bellied toad (Bombina variegata) is one such example. The underlying mechanisms behind the inability to accelerate development under desiccation remain largely unexplored. The hypothalamic-pituitary-interrenal (HPI) axis and corticosterone (CORT), which act synergistically with thyroid hormone, are thought to facilitate metamorphosis in response to desiccation stress. In this study, we aimed to investigate whether modification in the HPI axis, particularly CORT levels, contributes to the absence of adaptive plasticity in B. variegata under desiccation stress. The study design included four treatments: high water level, high water level with exogenous CORT, low water level, and low water level with metyrapone (a CORT synthesis inhibitor). The main objective was to evaluate the effects of these treatments on whole-body corticosterone levels, life history, morphological traits, and oxidative stress parameters during the prometamorphic and metamorphic climax developmental stages. While low water level had no effect on total corticosterone levels, larval period, body condition index, and metamorphic body shape, it negatively affected metamorph size, mass, and growth rate. Our findings suggest that constant exposure to desiccation stress over generations may have led to modifications in the HPI axis activity in B. variegata, resulting in adaptation to changes in water level, evident through the absence of stress response. Consequently, CORT may not be a relevant stress indicator in desiccation conditions for this species.

Measurements of dune erosion processes during the RealDune/REFLEX experiments

Nearshore hydro- and morphodynamic data were collected during a field experiment under calm conditions, moderate conditions, and storm conditions with dune erosion in the collision regime. The experiment was conducted on the Sand Engine near Kijkduin, the Netherlands, from October 18, 2021, to January 7, 2022. Two artificial unvegetated dunes were constructed just above the high water line to measure storm erosion and dune impacts from higher water levels and waves. During the experiment, three storms occurred that resulted in significant erosion of both dunes. The collected hydrodynamic data include pressure sensor and velocimeter data along two cross-shore transects. The collected morphodynamic data include bathymetry and topography surveys, optical backscatter sensor data in the inner surf zone, and a continuous cross-shore line-scanning lidar data set of the dune face. This comprehensive data set can be used to (1) study relevant nearshore hydrodynamic and morphodynamic processes that occur during calm conditions, moderate conditions, and storm conditions with dune erosion in the collision regime, and (2) validate existing dune erosion models.