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Many authors have pointed out the need for simpler assessment and management procedures for avoiding overexploitation in small-scale fisheries. Nevertheless, models for providing scientific advice for sustainable small-scale fisheries management have not yet been published. Here we present one model; the case of the Barefoot Fisheries Advisors (BFAs) in the Galician co-managed Territorial Users Rights for Fishing. Based on informal interviews, gray literature and our personal experience by being involved in this process, we have analyzed the historical development and evolution of roles of this novel and stimulating actor in small-scale fisheries management. The Galician BFA model allows the provision of good quality and organized fisheries data to facilitate and support decision-making processes. The BFAs also build robust social capital by acting as knowledge collectors and translators between fishers, managers, and scientists. The BFAs have become key actors in the small-scale fisheries management of Galicia and a case for learning lessons. [ABSTRACT FROM AUTHOR]

Presents a study on the impact of initial uncertainty in localized regions on numerical weather forecast sensitivity over North America. Description of the models, data sets and experiment design; Impact of the initial uncertainty over North America; Discussion of results relative to adaptive targeting.

• We performed an enhanced solar energy forecast for two different sites. • The model was run and validated with two real PV power datasets for one full year. • The forecast for Spanish site is accurate for 24 h and 48 h (NMAE 5.18% and 5.19%). • Also, the Indian site presents good results in both horizons (NMAE 5.59% and 6.17%). • The use of AOD input improves up to 10% the accuracy of the model during high AOD load days. Regional meteorological models are becoming a generalized tool for solar energy production forecasting, due to their capacity to simulate different types of cloud formations and their interaction with solar radiation. The greater demand for reliable forecasting tools in the energy industry is the motivation for the development of an integrated system that combines the Weather Research and Forecasting atmospheric model package designed to fulfill the needs of solar energy applications (WRF-Solar), with the solaR power plant model. This study focuses on the use and validation of this coupled tool in forecasting the energy production for two real solar plants, one in Spain and another in India. A period of one year for the Spanish emplacement and nine months for the Indian site are simulated with a daily operational forecasting set-up. Aerosol data from the Copernicus Atmosphere Monitoring Service (CAMS) are considered in the calculations, a new capability in WRF-Solar. Power predictions are obtained and compared with real data from the inverters of both plants provided by the operating company. The results show that WRF-Solar obtains accurate forecasts of global, direct, and diffuse radiation and of the ambient temperature that solaR uses as input to predict the energy production of the solar plants. The normalized Mean Annual Errors (NMAE) is 5.18% in the Spanish and 5.59% in the Indian plant for the first day of predictions, demonstrating a reliable performance of the forecasting system in different climate locations. The skill scores for the second day of prediction are also promising, with practically the same errors as the previous day (5.19% and 6.17 for Spain and India respectively). By comparing the model predictions, with and without AOD input during the dustiest days in the Spanish site, the importance of the aerosol effect inclusion is demonstrated with an improvement up to 10% in the energy forecast. These results demonstrate the system's potential both for solar plant operation and energy market applications. [ABSTRACT FROM AUTHOR]

Small-scale fisheries (SSFs), which provide an important source of livelihood for many coastal communities, are at risk from climate change. Benthic organisms are likely to be particularly affected by the impacts of climate change due to their low spatial mobility, which limits their capacity for adaptation. Therefore, SSFs that target sedentary resources ("S-fisheries") will potentially be among the most impacted types of fishery. The pathways of such impacts can be studied in an integrated approach by means of social-ecological vulnerability assessment. The stalked barnacle (Pollicipes pollicipes) fishery, one of the most important S-fisheries in Galicia (NW Spain), represents a complex social-ecological system rooted within the culture of the region. Along Galician coast, this benthic resource is co-managed by the territorial use rights in fisheries (TURFs) scheme. The vulnerability assessment involves ranking TURF systems according to the exposure of the resource to climate hazards, the sensitivity of dependent people and the capacity of the system to adapt to the impacts. After analyzing 26 stalked barnacle TURFs (79% of all Galician TURFs), we identified the most vulnerable zones (Muxía and O Pindo), as indicated by high levels of ecological vulnerability and social sensitivity and low adaptive capacity. We discuss different ways of increasing the adaptive capacity of TURFs based on local knowledge and literature reviews. Vulnerability assessment represents a powerful tool that can be used to help policy-makers develop adaptation strategies needed at different time scales, ultimately contributing towards better informed, sustainable and efficient fisheries management. [ABSTRACT FROM AUTHOR]

The increase in the number and quality of numerical moisture tracking tools has greatly improved our understanding of the hydrological cycle in recent years. However, the lack of observations has prevented a direct validation of these tools, and it is common to find large discrepancies among the results produced by them, especially between Eulerian and Lagrangian methodologies. Here, we evaluate two diagnostic tools for moisture tracking, WaterSip and UTrack, using simulations from the Lagrangian model FLEXPART. We assess their performance against the Weather Research and Forecasting (WRF) model with Eulerian Water Vapor Tracers (WRF-WVTs). Assuming WRF-WVTs results as a proxy for reality, we explore the discrepancies between the Eulerian and Lagrangian approaches for five precipitation events associated with atmospheric rivers and propose some physics-based adjustments to the Lagrangian tools. Our findings reveal that UTrack, constrained by evaporation and precipitable water data, has a slightly better agreement with WRF-WVTs than WaterSip, constrained by specific humidity data. As in previous studies, we find a negative bias in the contribution of remote sources, such as tropical ones, and an overestimation of local contributions. Quantitatively, the root-mean-square-error (RMSE) for contributions from selected source regions is 5.55 for WaterSip and 4.64 for UTrack, highlighting UTrack's narrowly superior performance. Implementing our simple and logical corrections leads to a significant improvement in both methodologies, effectively reducing the RMSE by over 50 % and bridging the gap between Eulerian and Lagrangian outcomes. Our results suggest that the major discrepancies between the different methodologies were not rooted in their inherently different nature, but in the obviation of basic physical considerations that may be easily straightened out. [ABSTRACT FROM AUTHOR]

Here we ask the following questions: (1) What is the depth of soil water uptake across the vast Amazon ecosystem and across the wet and dry seasons or wet and dry years? Reports of 18m deep roots in terra-firme trees and 0.2m deep roots in lowland swamp forests suggest the influence of local drainage conditions. (2) Is the uptake source the recent rain reaching shallow soils, or past wet-season rain stored in deep soils, or past rain that reached the water table which sends the water back up through capillary flux, or past rain that flowed down the topographic gradient from ridges to valleys (i.e., upland to lowland subsidy)? We address these questions through a synthesis of observations compiled from the literature, and a dynamic and hillslope-resolving model informed by the synthesis, which explicitly couples surface-groundwater and root uptake, driven by reanalysis atmosphere and observed leaf area. Our findings shed critical lights on the depth and origin of the water supporting Amazon photosynthesis, hence their resilience or vulnerability to seasonal-interannual droughts across the Amazon. [ABSTRACT FROM AUTHOR]

The Western Mediterranean Region (WMR) is characterized by a high frequency in the occurrence of torrential rainfall episodes and floods that cause severe damages, with a very high social and economic impact. Several particularities make this region prone to extreme rains; the mild sea waters or its orography are some examples. Most cases occur in autumn, when the combination of a still warm sea surface temperature (after a peak in late summer), and a southward displacement of the jet stream (which usually favors the appearance of Atlantic lows or cut-off-lows affecting the WMR), make this season the most favourable for the development of these adverse episodes.Here, we developed a new WMR extreme precipitation events database for the period 1980-2015. The events' detection is based on the MESCAN precipitation analysis dataset (recently available in the ECMWF MARS archive at 5.5 km) and the HYMEX flood database. Then, by applying the k-means method of cluster analysis, the identified episodes are classified into different groups based on the synoptic pattern of each event. The procedure yields a dataset consisting of the main episodes, their associated floods (if any) and the referral atmospheric circulation pattern associated with each event. In the future, this archive could be useful in many other different studies of WMR torrential rains. For example, we plan to use this database for the study of moisture sources, trying to associate some recurrent sources to each event cluster created. [ABSTRACT FROM AUTHOR]

Wildfires are a common natural hazard in the west of the Iberian Peninsula during the warm season, having devastating effects on the environment and also affecting the region economically. It is well known that atmospheric conditions (wind, temperature, humidity, etc.), together with topography and vegetation characteristics, strongly influence the propagation of fires. These three factors are considered in the WRF-FIRE model, which couples a mesoscale atmospheric model (WRF) with a semi-empirical fire spread model, and thus can be used as a fire-spread modelling tool.We present here preliminary simulations with WRF-FIRE for Galician wildfires. There are some characteristics in this region that turn wildfire simulation more complicated, like generalized arson and the heterogeneous forest distribution. As a result, the accuracy in the location of the ignition points, which are often multiple, and the adequacy of the fuel characterization may play an important role. We assess the influence of these factors with simulations of past wildfires and compare results with satellite images.A correct implementation of the model in this region can be useful to improve the mapping of high-risk fire areas or to obtain operational fire spread predictions that can help firefighting. [ABSTRACT FROM AUTHOR]

Ecosystem productivity and resilience to environmental stress are tightly linked to soil water availability and plant rooting depth. We explore here the controls on plant root uptake, imposed by climate and groundwater accessibility, underlying the spatial and temporal patterns of rain-fed and groundwater-fed ecosystems at the large and catchment scale. We estimate root water-uptake depths with an inverse model, based on observed productivity and atmosphere, at 30″ (∼1-km) global grids to capture the topography critical to soil hydrology. Results reveal strong sensitivities of rooting depth to local soil water profiles determined by precipitation infiltration depth from the top (reflecting climate and soil), and groundwater table depth from below (reflecting topography-driven land drainage). They indicate highly variable uptake-depth across seasonal and local hydrologic gradients, and a far more common occurrence of deep (>5m) uptake than previously thought. The resulting patterns of plant rooting depth bear a strong topographic and hydrologic signature at catchment to global scales and explain the contrasting rooting depths observed under the same climate for the same species but at distinct topographic positions. These results highlight the role of groundwater accesibility as one of the main organizing principles shaping ecosystem patterns and stress response at the catchment scale. [ABSTRACT FROM AUTHOR]

The precipitation recycling (PR) ratio is an important indicator that quantifies the land-atmosphere interaction strength in the Earth system's water cycle. To better understand how the heterogeneous land surface in the Tibetan Plateau (TP) contributes to precipitation, we used the water-vapor tracer (WVT) method coupled with the Weather Research and Forecasting (WRF) regional climate model. The goals were to quantify the PR ratio, in terms of annual mean, seasonal variability and diurnal cycle, and to address the relationships of the PR ratio with lake treatments and precipitation amount. Simulations showed that the PR ratio increases from 0.1 in winter to 0.4 in summer when averaged over the TP with the maxima centered at the headwaters of three major rivers (Yangtze, Yellow and Mekong). For the central TP, the highest PR ratio rose to over 0.8 in August, indicating that most of the precipitation was recycled via local evapotranspiration in summer. The larger daily mean and standard deviation of the PR ratio in summer suggested a stronger effect of land-atmosphere interactions on precipitation in summer than in winter. Despite the relatively small spatial extent of inland lakes, the treatment of lakes in WRF significantly impacted the calculation of the PR ratio over the TP, and correcting lake temperature substantially improved both precipitation and PR ratio simulations. There was no clear relationship between PR ratio and precipitation amount; however, a significant positive correlation between PR and convective precipitation was revealed. This study is beneficial for the understanding of land-atmosphere interaction over high mountain regions. [ABSTRACT FROM AUTHOR]

Forest--savanna boundaries are ecotones that support complex ecosystem functions and are sensitive to biotic/abiotic perturbations. What drives their distribution today and how it may shift in the future are open questions. Feedbacks among climate, fire, herbivory, and land use are known drivers. Here, we show that alternating seasonal drought and waterlogging stress favors the dominance of savanna-like ecosystems over forests. We track the seasonal water-table depth as an indicator of water stress when too deep and oxygen stress when too shallow and map forest/savanna occurrence within this double-stress space in the neotropics. We find that under a given annual precipitation, savannas are favored in landscape positions experiencing double stress, which is more common as the dry season strengthens (climate driver) but only found in waterlogged lowlands (terrain driver). We further show that hydrological changes at the end of the century may expose some flooded forests to savanna expansion, affecting biodiversity and soil carbon storage. Our results highlight the importance of land hydrology in understanding/predicting forest--savanna transitions in a changing world. [ABSTRACT FROM AUTHOR]

The effects of groundwater dynamics on the representation of water storage and evapotranspiration (ET) over southern South America are studied from simulations with the Noah-MP land surface model. The model is run with three different configurations: one including the Miguez-Macho and Fan groundwater scheme, another with the Simple Groundwater Model (SIMGM), and the other with free drainage at the bottom of the soil column. The first objective is to assess the effects of the groundwater schemes using a grid size typical of regional climate model simulations at the continental scale (20 km). The phase and amplitude of the fluctuations in the terrestrial water storage over the southern Amazon are improved with one of the groundwater schemes. An increase in the moisture in the top 2 m of the soil is found in those regions where the water table is closer to the land surface, including the western and southern Amazon and the La Plata basin. This induces an increase in ET over the southern La Plata basin, where ET is water limited. There is also a seasonal increase in ET during the dry season over parts of the southern Amazon. The second objective is to assess the role of the horizontal resolution on the effects induced by the Miguez-Macho and Fan groundwater scheme using simulations with grid sizes of 5 and 20 km. Over the La Plata basin, the effect of groundwater on ET is amplified at the 5-km resolution. Notably, over parts of the Amazon, the groundwater scheme increases ET only at the higher 5-km resolution. [ABSTRACT FROM AUTHOR]

A sensitivity study of the impact of a groundwater scheme on hydrometeorological variables in coupled land-atmosphere simulations over southern South America is presented. It is found that shallow water tables in the groundwater scheme lead to reduced drainage and even upward capillary fluxes over parts of the central and southern La Plata basin. This leads to an increase in the simulated moisture in the root zone, which in turn produces an increase in evapotranspiration (ET) over the southern part of the domain, where ET is water limited. There is also a decrease in the near-surface temperature, in the range 0.5°-1.0°C. During the dry season, the increases in ET and relative humidity over the central La Plata coincide with an increase in precipitation downstream. Including groundwater leads to an increase in precipitation over parts of the central and southern La Plata basin during the early rainy season (October-December). The overall increase in ET and precipitation over the southern La Plata basin during the early rainy season is 13% and 10%, respectively. The additional precipitation comes from both an increase in the availability of atmospheric moisture when the groundwater scheme is used and its effect on the atmospheric instability. In the La Plata basin, including a representation of groundwater increases simulated precipitation and partially alleviates a warm and dry bias present in simulations without realistic subsurface hydrology. [ABSTRACT FROM AUTHOR]

We have followed the recovery of gaps produced either by harvesters or by scientists in stands of stalked barnacle (Pollicipes pollicipes) during two years in four regions of Europe (SW Portugal, Galicia and Asturias in Spain and Brittany in France; n = 423 gaps), which was extended to four years in Asturias (n = 252 gaps). The presence of adult conspecifics in the margins of the gaps increased by at least four times the probability of initiation of their recovery. After two years of follow-up in the four regions, 90% of the gaps with adjacent conspecifics had initiated recolonization as opposed to only 60% in gaps with no adjacent adults. These figures remained stable after three years of follow up in Asturias, pointing to a large fraction of gaps which are recalcitrant to recolonization. Once initiated, the median rate of recovery after latency was 0.47 cm2/month in the four regions and 0.61 cm2/month in Asturias, increasing from 0.5 to 2.5 cm2/month for a 0 to 25 cm increase of perimeter in contact with adults, which is consistent with heavy recruitment on the stalks of conspecifics. The median estimated time to full recovery of gaps which initiated recovery was 2.65 years, thus recolonization is a slow process. Our results point to the main recommendations that a barnacle clump should never be removed entirely, so that the remaining adults serve as recruitment nuclei for the population, and that a maximum scraper width of 3.5 cm should be set to limit accessory capture of non-target individuals. [ABSTRACT FROM AUTHOR]

Understanding large-scale spatial and temporal patterns of marine populations is a central goal in ecology, which has received renewed attention under climate change. However, few studies explore the large-scale dynamics of populations using standardized protocols and during the same time frames. We studied the phenology and intensity of reproduction and recruitment for the intertidal stalked barnacle Pollicipes pollicipes over an European scale and described their potential linkages with environmental variables. This species supports profitable fisheries in the Iberian Peninsula (Spain and Portugal). In Brittany (France), we had observed a significant lower reproductive effort (long non-breeding season, short breeding period in summer) and low values of recruitment intensity. This pattern may be related to the fact that Brittany corresponds to the northern limit of the distribution of this species in continental Europe. On the Iberian Peninsula, the most different region was Galicia (Spain), with Asturias (Spain) and SW Portugal being more similar. In Galicia, we have observed a contradictory pattern characterized by the absence of a non-breeding period and by a shorter recruitment season than observed in other Iberian regions. Our results suggest that air temperature, SST and chlorophyll-a might be related to the variability in reproduction and recruitment patterns of P. pollicipes. Moreover, spring and early summer upwelling in SW Portugal and Galicia might be inhibiting recruitment in this period. At the northern limit, the expected increase in performance under climate change might facilitate the recovery of populations after exploitation, increasing the resilience of the resource to fishing pressure. [ABSTRACT FROM AUTHOR]

The lack of effective governance is a major concern in small-scale fisheries. The implementation of governance that encompasses the three pillars of sustainability (social, economic, and ecological) is still a worldwide challenge. We examined nine stalked barnacle fisheries (Pollicipes pollicipes) across Southwest Europe to better understand the relationship between governance elements and sustainability. Our results show that nested spatial scales of management, the access structure, co-management, and fisher's participation in monitoring and surveillance promote sustainability. However, it is not the mere presence of these elements but their level of implementation that drives sustainability. Efforts should be placed in the accomplishment of a minimum combination of local scales of management, access rights through individual quotas, instructive-consultative co-management and functional participation. Surpassing this threshold in future governance structures will start to adequately promote social, economic and ecologically sustainability in small-scale fisheries. [ABSTRACT FROM AUTHOR]

Environmental controls on the biogeographic distribution of species are becoming increasingly relevant under the present climate change conditions. The reproductive cycle of the acorn barnacle Semibalanus balanoides at its southernmost European distribution limit in Galicia (Northwest Iberian Peninsula) was studied in two locations (42.57°N 8.96°W, 42.61°N 8.89°W) with different temperatures during a 4-year time series (2012–2016), where an isolated population breeds even though the temperature thresholds documented for northern populations of the species are exceeded. Ovary production, total number of embryos and pre-hatching developmental stage were significantly higher in the colder location than in the warmer one. Fecundity was higher in colder reproductive seasons mediated by upwelling regime and food supply 3 months prior to fertilization. Investment in ovary tissue was favored by high temperatures and food availability, whereas suspended sediment was negatively correlated with investment in ovary tissue. Larvae release was associated with high temperatures and suspended sediment. Phenology of reproductive events was similar to what was described in farther north populations. Results indicated that reproductive output of the species at its southernmost European distribution limit is comparable to that reported in northern latitudes and suggest adaptation or acclimatization to local environmental conditions as maturation of gonads and fertilization was successfully carried out at higher temperatures than documented in northern European populations. [ABSTRACT FROM AUTHOR]

The western Mediterranean region often suffers from the devastating effects of flooding, caused by enormous rain accumulations that sometimes resemble the values produced by tropical systems. Despite the climatic and social relevancy of this type of episodes, there are some fundamental questions that would still be difficult to answer today, for example: where within the region are more cases recorded? or, which were the most potentially dangerous episodes? In this study, we identify, and then gather and unify information from, all the daily events occurred from 1980 to 2015. Using the MESCAN high-resolution gridded rainfall dataset, events are detected and for each case, the date and affected regions are recorded. Subsequently, events are ranked according to their magnitude and classified by weather type. In addition, flood data from the FLOODHYMEX and EM-DAT databases are used to check whether the precipitation episodes resulted in flooding. All this information is collected into a publicly available single database. Results show that the highest number of events per year is recorded in the Languedoc-Roussillon region (France) and in the Valencian Community (Spain). The cases of greatest magnitude, which are associated with a larger number of floods, present a very marked seasonality, with about 80% of them occurring in September, October and November. Finally, we show that only four weather types are present in most of the days with hazardous rainfall in the western Mediterranean. The most hazardous situation is characterized by a low-pressure area at all tropospheric levels in the eastern Atlantic, forming a block pattern with an anticyclonic ridge that tends to extend from the Central Mediterranean to Central Europe. About 40% of the most extraordinary cases are associated with this configuration. As an example, the infamous Piedmont (Italy) 1994 episode, in the top 10 of the ranking, was produced by an atmospheric pattern of this type. • We identify and rank Hazardous Prec. Events (HPE) in the West Mediterranean in 36 yr. • HPEs affect mainly the coast, most frequently of Southern France and Eastern Spain. • HPEs occur most often in autumn, especially the most intense. • Four recurrent weather types are associated to most HPEs. • We gather all information about HPEs into a publicly available single database. [ABSTRACT FROM AUTHOR]

Continued deforestation in the Amazon forest can alter the subsurface/surface and atmospheric branches of the hydrologic cycle. The sign and magnitude of these changes depend on the complex interactions between the water, energy, and momentum budgets. To understand these changes, we use the weather research and forecasting (WRF) model with improved representation of groundwater dynamics and the added feature of Amazonian moisture tracers. The control simulation uses moderate resolution imaging spectroradiometer (MODIS) based observations of land use, and the deforestation simulations use a "business-as-usual" scenario projected for 2040-2050. Our results show that deforestation leads to changes that are seasonally very different. During the dry season, deforestation results in increased albedo and less available net radiation. This change, together with reduced leaf area, results in decreased evapotranspiration (ET), less atmospheric moisture of Amazonian origin, and an increase in temperature. However, we find no changes in precipitation over the basin. Conversely, during the wet season, surface winds increase significantly due to decreased surface roughness. Vapor transport increases throughout the deforested region and leads to an increase in easterlymoisture export, and significant decrease in precipitation within the deforested regions of Eastern Amazon. Contrary to expectations, the moisture tracers in WRF show no evidence that precipitation decreases are due to recycling or changes in stability. [ABSTRACT FROM AUTHOR]

Abstract Regional meteorological models are becoming a generalized tool for wind resource forecasting, due to their capacity to simulate local flow dynamics impacting wind farm production. This study focuses on the case of production forecast and validation for a real onshore wind farm using high horizontal and vertical resolution WRF (Weather Research and Forecasting) model simulations. The wind farm is located in Galicia, in the northwest of Spain, in a complex region with high wind resource. Utilizing the Fitch scheme, specific for wind farms, a period of one year is simulated with a daily operational forecasting set-up. Power and wind predictions are obtained and compared with real data at each wind turbine hub, provided by the management company. Results show that WRF yields good wind power operational predictions for this kind of wind farms, due to a good representation of the planetary boundary layer behaviour of the region and the good performance of the Fitch scheme under these conditions. The best mean annual error (MAE) obtained is 1.87 m/s for wind speed and 14.75% for wind power. By comparing experiments with and without Fitch scheme, we estimate wind resource losses in the area due to the wake disturbances. The mean annual wake or environmental footprint of the farm extends for several kilometres in the southwest-northeast direction of the prevailing winds, with resource losses of 0.5% even at 17 km from the turbines. Highlights • We perform High-resolution (333 m) WRF forecasting for a farm in complex terrain. • Detailed validation with observations at the nacelle of each turbine for one full year. • Forecasts are very skillful: wind speed MAE = 1.87 m/s and wind power NMAE = 14.75%. • Wind turbine scheme forecast is clearly better when the farm is impacted by its wake. • Mean annual wake resource loss is significant, it extends for several km from the farm. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assess mechanisms regulating evapotranspiration (E) in Amazonia and cerrado. [•] Groundwater and deep root uptake can both sustain E during the dry season. [•] Canopy stomatal conductance regulates E even at sites with little water limitation. [•] Models capturing observed patterns in E may still poorly represent these mechanisms. [•] Model developments should focus on improved biological controls on E. [Copyright &y& Elsevier]

In this paper we examine the effect of Gross Domestic Product (GDP) on the level of fish intake in China in comparison with the rest of the world. We also analyse the origin and destination of China’s seafood products in order to understand the main patterns during the last decades. The results show that in the 1961–2011 period the rate of growth of the GDP in China doubled that of other developing regions, while the daily fish intake of China increased fourfold, making China the largest fish consumer in the world. Given the size and scale of China’s role in production, consumption, and global transformation of seafood markets, China is shaping a new era of industrialization in the history of the fishing industry. [ABSTRACT FROM AUTHOR]

Heat waves are expected to increase in duration and frequency, impacting coastal ecosystems, especially intertidal organisms living near their thermal tolerance limits. Sedentary infaunal species are limited to some extent in escapes from sudden temperature changes, rather modifications to their physiology and behaviour are expected. This may lead to strong ecological and economic impacts on commercial bivalve species, such as Venerupis corrugata , Ruditapes decussatus , the introduced Ruditapes philippinarum and Cerastoderma edule , the most relevant in NW Spain. We investigated lethal and sublethal effects of heat during low tide on these species in the laboratory. Summer temperatures experienced within field, shallow sediments at approximately 2 cm depth i.e. 20 °C (control), 27 °C, 32 °C, and 37 °C, were replicated during four consecutive days and the diffusion of heat at the burrowing depth of each species was estimated; temperature exposure was expressed as degree hours above 22 °C. After two days of tidal exposure, C. edule and V. corrugata suffered significant mortalities, and also the most dramatic decrease in scope for growth (SFG) as well as reduction in burrowing activity. After four days under stress, all species had negative SFG. On recovery, species showed compensation at longer exposures, particularly C. edule. These effects of temperature on mortality, growth potential and burrowing ability may increase the time to achieve commercial size and exposure to predation. Particularly, V. corrugata , with a center of distribution lower in the intertidal and subtidal, and C. edule , shallower in the sediment, may be the most affected. Clearly the intensity and frequency of heat waves will affect these key species in the intertidal sediment flats changing ecosystem functioning and fisheries management strategies. Image 1 • Effects of sediment thermal stress at low tide on four infaunal bivalves studied. • Heat transfer into sediment was calculated depending on the species burrowing depth. • After 24 h of stress mortality was greater in the most superficial species. • Scope for growth decreased to negative values at higher temperature exposures. • Responses differed depending on preferment habitat and burrowing depth of species. [ABSTRACT FROM AUTHOR]

• Response of bivalves differed depending on intensity of salinity stress and season. • Salinity ≤15 caused sharp decrease in SFG and activity (valve closure, burrowing). • For salinities ≥20 diverse responses among species as low activity or compensation. • SFG was an useful indicator to assess salinity stress in adult bivalves. The abilities of estuarine species to respond to salinity fluctuations by behavioural and physiological responses can determine the maintenance of populations, particularly in the context of climate change. The native clams Ruditapes decussatus and Venerupis corrugata , the native cockle Cerastoderma edule and the introduced clam Ruditapes philippinarum are important resources in Galician (NW Spain) coast. As inhabitants of estuaries, these species are exposed to frequent salinity fluctuations as a result of heavy rains. This study investigated the short-term sublethal effects of salinity drops on their physiological (scope for growth, SFG) and behavioural (valve closure and burrowing activity) responses. Bivalves were exposed to simulated tidal cycles and similar salinities to the field conditions, i.e., four salinity ramps (5–20, 10–25, 15–30 and 30–30) during six days over three different periods of the year (autumn, winter and spring). The overall response was the same for all species under the lower salinities (5, 10 and 15), with a dramatic reduction of pumping activity, SFG and burrowing. Results differed among species under the higher salinities (20, 25 and 30). While C. edule was the most affected species in autumn showing no recovery despite having higher SFG compared to the venerids, R. decussatus was more resistant in all seasons despite having the lowest SFG compared to the rest of species. In winter, V. corrugata was the most vulnerable due to lower SFG at the lowest salinities. All species showed a compensation pattern in spring that led to non-recovery of individuals. Burrowing ability had similar patterns to SFG in autumn and winter but differed in spring, when recovery was the general pattern. The decrease of burrowing ability at lower salinities during stress seen to some degree in all species can increase vulnerability to predation. Results suggest that differential responses of lower activity over time could be related to the physiological condition and habitat preferences of each species and should be taken in consideration for management plans in the context of climate change. The results drive a discussion of the usefulness of SFG as the metric with which to assess salinity stress in adult bivalves and the need in future research to increase frequency and duration of stresses in concert with variables such as food availability. [ABSTRACT FROM AUTHOR]

The link between the behavior of organisms living within the sediment and benthic-pelagic coupling is critical to our interpretation of impacts of physiological stress. The rapidity with which organisms respond to a stress and recover once a stress is removed impacts the cascade of secondary effects that result from such behavioral changes. Such behavioral responses, although critical to our understanding, are difficult to quantify, particularly for organisms such as bivalves that inhabit sediments, the most common spatial habitat on Earth. Sublethal responses to fluctuating stressors such as salinity are rarely quantified in terms of activity. Here we do so using a combination of direct observations and pressure sensors, which allow us to record burrowing and other hydraulic activities. Based on our field observations and the literature, we predicted that there would be a breakpoint in behavior between salinities of 15 and 20 and that below this breakpoint the animals would significantly reduce activities including burrowing and feeding. The data presented support this prediction; burrowing was reduced in all three species at salinities at or below 15 as were fecal deposition and appearance of siphons above the sediment surface. These data are consistent with the prediction that under conditions of large fluctuations in salinity the magnitude of the link to primary productivity and nutrient availability from the benthos will be significantly reduced. • Tidally varying salinity exposures significantly reduced clam activities in sediment. • The breakpoint for activity reduction was between 15 and 20 psu as expected. • The defensive response to salinity reduction was valve closure in all three species. • Reductions in behaviors have impacts for ecosystem functioning. [ABSTRACT FROM AUTHOR]

Land degradation is a complex socio-environmental threat, which generally occurs as multiple concurrent pathways that remain largely unexplored in Europe. Here we present an unprecedented analysis of land multi-degradation in 40 continental countries, using twelve dataset-based processes that were modelled as land degradation convergence and combination pathways in Europe's agricultural (and arable) environments. Using a Land Multi-degradation Index, we find that up to 27%, 35% and 22% of continental agricultural (~2 million km 2 ) and arable (~1.1 million km 2 ) lands are currently threatened by one, two, and three drivers of degradation, while 10-11% of pan-European agricultural/arable landscapes are cumulatively affected by four and at least five concurrent processes. We also explore the complex pattern of spatially interacting processes, emphasizing the major combinations of land degradation pathways across continental and national boundaries. Our results will enable policymakers to develop knowledge-based strategies for land degradation mitigation and other critical European sustainable development goals., (© 2024. The Author(s).)