Anthropogenic and environmental determinants of Greater Flamingo Phoenicopterus roseus breeding numbers and productivity in the Camargue (Rhone delta, southern France)

Predicting how bird populations may respond to climate change is a major challenge which could be addressed by understanding how past environmental processes have driven the variations of breeding population size and productivity. In inhabited regions, this issue may be complicated by the interference associated with heterogeneous levels of habitat management. Here, we have explored how several hydrological variables influenced the breeding of the Greater Flamingo Phoenicopterus roseus in the Camargue (Rhone delta, southern France) over a 28‐year period (1974–2001). In this region, Flamingos breed in a commercial salt pan. They forage in both salt pans and adjacent brackish lagoons. We hypothesized that breeding numbers, productivity and body condition of chicks at fledging were influenced positively by water levels of the Vaccares, the main lagoon of the delta, in spring (water and food availability) and the Rhone discharge in winter (nutrient availability in the salt pans). We controlled for variations of the flooding date of the breeding salt pan by the salt company and the size of the breeding island. We first found the Vaccares water levels and Rhone discharge to be negatively correlated with the North Atlantic Oscillation (NAO). Secondly, the number of Flamingo breeding pairs (range 3560–22 200) increased by 1767 ± 1418 (95% CI) with a 10‐day advance of the flooding date of the breeding salt pan and by 1146 ± 1081 per 10‐cm water level rise in the Vaccares. Productivity was 0.46 ± 0.41 chicks per pair and could not be explained by any of the variables considered. Finally, chick body condition decreased with the number of breeding pairs and Rhone discharge. Our results show that (1) this intensely managed system remains sensitive to large‐scale climate variations, (2) the breeding of the Greater Flamingo is affected by both climate variations and management of the salt pan, and (3) the expected enhancement of delta productivity by high river discharge was absent, probably prevented by dykes and embankments along the river. The response of bird populations to climate variations can thus be complex in intensely managed biological systems as found in the Mediterranean. We encourage pursuing such analyses incorporating anthropogenic variables explicitly in order to expand our capacity to make inference on the future of these systems.     

The invasive red swamp crayfish as a predictor of Eurasian bittern density in the Camargue, France

Few data exist on the relationships between food levels and breeding density of the Eurasian bittern Botaurus stellaris , a vulnerable species of high-priority concern in Europe. Concurrent data were obtained on male bittern density and relative food abundance over a 3-year period in two wetlands totalling 2500 ha of Mediterranean reed marsh enclosing 25% of the French bittern population. Food abundance was estimated by sampling up to 25 hydrological units using a beach seine in early June of 2002, 2003 and 2004. The density of booming males in each hydrological unit was obtained by point counts and acoustic triangulation in May of the same years. The impact of food abundance on male bittern density was assessed by general regression models using a forward stepwise procedure with mosquitofish Gambusia affinis , carp Cyprinus carpio , other fish species, amphibians, red swamp crayfish Procambarus clarkii and other invertebrates as prey groups. Of these, only to crayfish abundance was bittern density related, contributing to 45% of the variance observed. When the impact of water level was taken into account, the relative abundance of crayfish explained 56% of the inter-annual differences in bittern density. Because crayfish are rich in calcium and well adapted to fluctuating hydroperiods alternating with drought intervals, they provide a good food source for the bitterns throughout the breeding season at the study sites. The loss of diversity and degradation reported from macrophyte-dominated marshes following crayfish invasion does not seem to apply to reed-dominated wetlands. It is further suggested that the recent increase in bittern numbers in the Camargue, while other French populations were decreasing, could in part be related to red swamp crayfish abundance.     

Diversity, distinctiveness and conservation status of the Mediterranean coastal dung beetle assemblage in the Regional Natural Park of the Camargue (France)

The Mediterranean region as a whole has the highest dung beetle species richness within Europe. Natural coastal habitats in this region are among those which have suffered severe human disturbance. We studied dung beetle diversity and distinctiveness within one of the most important coastal protected areas in the west Euro‐Mediterranean region (the regional Park of Camargue, southern France) and made comparisons of dung beetle assemblages with other nearby Mediterranean localities, as well as with other coastal protected area (Doñana National Park, Spain). Our finding showed that: (1) The species richness of coastal habitats in the Camargue is low and only grasslands showed a similar level of species richness and abundance to inland habitats of other Mediterranean localities. The unique habitats of the coastal area (beaches, dunes and marshes) are largely colonized by species widely distributed in the hinterland. (2) In spite of their low general distinctiveness, dune and marsh edges are characterized by the occurrence of two rare, vulnerable, specialized and large roller dung beetle species of the genus Scarabaeus. As with other Mediterranean localities, current findings suggest a recent decline of Scarabaeus populations and the general loss of coastal dung beetle communities in Camargue. (3) The comparison of dung beetle assemblages between the Camargue and Doñana shows that, in spite of the low local dung beetle species richness in the Camargue, the regional dung beetle diversity is similar between both protected areas. Unique historical and geographical factors can explain the convergence in regional diversity as well as the striking divergence in the composition of dung beetle assemblages between both territories.     

Projecting climate change impacts on species distributions in megadiverse South African Cape and Southwest Australian Floristic Regions: Opportunities and challenges

Increasing evidence shows that anthropogenic climate change is affecting biodiversity. Reducing or stabilizing greenhouse gas emissions may slow global warming, but past emissions will continue to contribute to further unavoidable warming for more than a century. With obvious signs of difficulties in achieving effective mitigation worldwide in the short term at least, sound scientific predictions of future impacts on biodiversity will be required to guide conservation planning and adaptation. This is especially true in Mediterranean type ecosystems that are projected to be among the most significantly affected by anthropogenic climate change, and show the highest levels of confidence in rainfall projections. Multiple methods are available for projecting the consequences of climate change on the main unit of interest – the species – with each method having strengths and weaknesses. Species distribution models (SDMs) are increasingly applied for forecasting climate change impacts on species geographic ranges. Aggregation of models for different species allows inferences of impacts on biodiversity, though excluding the effects of species interactions. The modelling approach is based on several further assumptions and projections and should be treated cautiously. In the absence of comparable approaches that address large numbers of species, SDMs remain valuable in estimating the vulnerability of species. In this review we discuss the application of SDMs in predicting the impacts of climate change on biodiversity with special reference to the species‐rich South West Australian Floristic Region and South African Cape Floristic Region. We discuss the advantages and challenges in applying SDMs in biodiverse regions with high levels of endemicity, and how a similar biogeographical history in both regions may assist us in understanding their vulnerability to climate change. We suggest how the process of predicting the impacts of climate change on biodiversity with SDMs can be improved and emphasize the role of field monitoring and experiments in validating the predictions of SDMs.     

Temperature-related mortality in France, a comparison between regions with different climates from the perspective of global warming

This paper aims to explain the results of an observational population study that was carried out between 1991 and 1995 in six regions (departments) in France. The study was to assess the relationship between temperature and mortality in a few areas of France that offer widely varying climatic conditions and lifestyles, to determine their thermal optimum, defined as a 3 degrees C temperature band with the lowest mortality rate in each area, and then to compare the mortality rates from this baseline band with temperatures above and below the baseline. The study period was selected because it did not include extreme cold or hot events such as a heatwave. Data on daily deaths from each department were first used to examine the entire population and then to examine men, women, various age groups and various causes of death (respiratory disease, stroke, ischaemic heart disease, other disease of the circulatory system, and all other causes excluding violent deaths). Mean temperatures were provided by the National Weather Service. The results depicted an asymmetrical V- or U-shaped relationship between mortality and temperature, with a thermal optimum lower for the elderly, and generally lower for women than for men except in Paris. The relationship was also different depending on the cause of death. In all cases, more evidence was collected showing that cold weather was more deadly than hot weather, and it would now be interesting to enlarge the study to include years with cold spells and heatwaves. Furthermore, the results obtained could be of great use in estimating weather-related mortality as a consequence of future climate-change scenarios.     

Creation of a nature reserve, its effects on hunting management and waterfowl distribution in the Camargue (southern France)

The eastern portion of the Camargue in southern France is divided into two parts: a natural wetland area of 2800 ha and an agricultural area of 5045 ha. In 1984 and 1989, a new protected area (1000 ha) was created on two contiguous former hunting estates. Analysis of aerial photographs (1968–1998) in conjunction with a field survey revealed, from 1984 to 1998, an increase of management for waterfowl hunting in natural wetlands located on the periphery of the new reserve, and a similar increase in the agricultural area amongst residual wetlands and former rice fields. Based on monthly aerial censuses, the size of the waterfowl population in the winter increased in this part of the delta by a factor of 3.8 following the creation of the reserve. Our results suggest that the creation of a reserve on former hunting estates resulted in greater attractiveness for ducks but also in the development of commercial hunting activity around the edge. This development increased fragmentation and uniformity of natural areas, including the loss of the unique Cladium mariscus habitat in the Camargue and resulted in the spatial expansion of waterfowl hunting areas in agricultural areas. It is associated with an increase in financial profit from waterfowl hunting. Our study highlights unexpected costs for nature conservation associated with the creation of a reserve. It illustrates the need for new models of wetland conservation where protection goals are not restricted to reserves, but also integrate conservation and economic development outside the protected areas.     

Potential impacts of future land use and climate change on the Red List status of the Proteaceae in the Cape Floristic Region, South Africa

Using spatial predictions of future threats to biodiversity, we assessed for the first time the relative potential impacts of future land use and climate change on the threat status of plant species. We thus estimated how many taxa could be affected by future threats that are usually not included in current IUCN Red List assessments. Here, we computed the Red List status including future threats of 227 Proteaceae taxa endemic to the Cape Floristic Region, South Africa, and compared this with their Red List status excluding future threats. We developed eight different land use and climate change scenarios for the year 2020, providing a range of best‐ to worst‐case scenarios. Four scenarios include only the effects of future land use change, while the other four also include the impacts of projected anthropogenic climate change (HadCM2 IS92a GGa), using niche‐based models. Up to a third of the 227 Proteaceae taxa are uplisted (become more threatened) by up to three threat categories if future threats as predicted for 2020 are included, and the proportion of threatened Proteaceae taxa rises on average by 9% (range 2–16%), depending on the scenario. With increasing severity of the scenarios, the proportion of Critically Endangered taxa increases from about 1% to 7% and almost 2% of the 227 Proteaceae taxa become Extinct because of climate change. Overall, climate change has the most severe effects on the Proteaceae, but land use change also severely affects some taxa. Most of the threatened taxa occur in low‐lying coastal areas, but the proportion of threatened taxa changes considerably in inland mountain areas if future threats are included. Our approach gives important insights into how, where and when future threats could affect species persistence and can in a sense be seen as a test of the value of planned interventions for conservation.     

Modelling the recent historical impacts of atmospheric CO2 and climate change on Mediterranean vegetation

During the past century, annual mean temperature has increased by 0.75°C and precipitation has shown marked variation throughout the Mediterranean basin. These historical climate changes may have had significant, but presently undefined, impacts on the productivity and structure of sclerophyllous shrubland, an important vegetation type in the region. We used a vegetation model for this functional type to examine climate change impacts, and their interaction with the concurrent historical rise in atmospheric CO₂. Using only climate and soil texture as data inputs, model predictions showed good agreement with observations of seasonal and regional variation in leaf and canopy physiology, net primary productivity (NPP), leaf area index (LAI) and soil water. Model simulations for shrubland sites indicated that potential NPP has risen by 25% and LAI by 7% during the past century, although the absolute increase in LAI was small. Sensitivity analysis suggested that the increase in atmospheric CO₂ since 1900 was the primary cause of these changes, and that simulated climate change alone had negative impacts on both NPP and LAI. Effects of rising CO₂ were mediated by significant increases in the efficiency of water‐use in NPP throughout the region, as a consequence of the direct effect of CO₂ on leaf gas exchange. This increase in efficiency compensated for limitation of NPP by drought, except in areas where drought was most severe. However, while water was used more efficiently, total canopy water loss rose slightly or remained unaffected in model simulations, because increases in LAI with CO₂ counteracted the effects of reduced stomatal conductance on transpiration. Model simulations for the Mediterranean region indicate that the recent rise in atmospheric CO₂ may already have had significant impacts on productivity, structure and water relations of sclerophyllous shrub vegetation, which tended to offset the detrimental effects of climate change in the region.     

In vitro and in situ studies on nitrate disappearance in water-sediment systems of the Camargue (southern France)

Results of in vitro and in situ experiments on nitrate disappearance from water-sediment systems in the Camargue are described.In the in vitro experiments two factors were studied: temperature and organic matter. After a first addition of KNO₃ to these sediments, the concentration of organic matter exerted a strong influence on the disappearance rate of nitrate at 25 °C and 15 °C but not at 2 °C. After a second addition of nitrate at 25 °C and 15 °C the denitrification rate increased by approximately 10%, probably because the activity of the bacterial population had increased.Experiments in situ in freshwater temporary marshes showed that nitrate disappeared at approximately twice the rate at similar temperature in vitro.After the first addition of nitrate in the in vitro experiments the concentration of nitrite in the water above the sediment reached about 10% of the concentration of total dissolved inorganic nitrogen at 2 °C and 15 °C. These high concentrations were not found after the first addition at 25 °C or after the second addition of nitrate at 25 °C and 15 °C. In the in situ experiments, however, high concentrations of nitrite were found.     

Assessing the impacts of climate change and land transformation on Banksia in the South West Australian Floristic Region

Aim To determine the potential combined effects of climate change and land transformation on the modelled geographic ranges of Banksia. Location Mediterranean climate South West Australian Floristic Region (SWAFR). Methods We used the species distribution modelling software Maxent to relate current environmental conditions to occurrence data for 18 Banksia species, and subsequently made spatial predictions using two simple dispersal scenarios (zero and universal), for three climate‐severity scenarios at 2070, taking the impacts of land transformation on species’ ranges into account. The species were chosen to reflect the biogeography of Banksia in the SWAFR. Results Climate‐severity scenario, dispersal scenario, biogeographic distribution and land transformation all influenced the direction and magnitude of the modelled range change responses for the 18 species. The predominant response of species to all climate change scenarios was range contraction, with exceptions for some northern and widespread species. Including land transformation in estimates of modelled geographic range size for the three climate‐severity scenarios generally resulted in smaller gains and larger declines in species ranges across both dispersal scenarios. Including land transformation and assuming zero dispersal resulted, as expected, in the greatest declines in projected range size across all species. Increasing climate change severity greatly increased the risk of decline in the 18 Banksia species, indicating the critical role of mitigating future emissions. Main conclusions The combined effects of climate change and land transformation may have significant adverse impacts on endemic Proteaceae in the SWAFR, especially under high emissions scenarios and if, as expected, natural migration is limiting. Although these results need cautious interpretation in light of the many assumptions underlying the techniques used, the impacts identified warrant a clear focus on monitoring across species ranges to detect early signs of change, and experiments that determine physiological thresholds for species in order to validate and refine the models.     

Response of Juniperus phoenicea on sandy dunes in the Camargue (France) to water and saline constraint in summer

The ‘Bois des Rièges’ woodland occurs on the relic littoral dunes in the National Reserve of the Camargue. Although surrounded by brackish ponds and saline lands with very salt groundwater close to the surface, the dunes are covered with non-halophytic vegetation of herbaceous shrubs and trees, including the dominant shrub Juniperus phoenicea. This is due to the presence of a freshwater lens beneath the dunes supplied by rains, and floating in hydrodynamic equilibrium upon the saline aquifer. The importance and duration of the freshwater stock depends on the precipitation-evapotranspiration balance as well as on the size of the dune. From the end of the spring to the autumn rain period this freshwater stock is considerably reduced, while the capillary potential in the zone of aeration of soil and the osmotic potential of the soil solution, influenced by capillary rise of the brackish groundwater, decrease. In summer the vegetation is thus subjected to severe drought caused by lack of water or salt excess, to which it must adjust its biological activity. The water relationships in the soil-plant system have been studied along a transect between the top and the borders of a dune surrounded by saline lands. Using simultaneous water potential measurements of the sunny and shady sides of Juniperus trees daily and seasonal transpiration regulations were studied. The preliminary results indicate that trees on the border of the dune as well as on tops are absorbing water from the same freshwater lens in the middle of the dune.     

Climate and land use change impacts on Mediterranean high-mountain vegetation in the Apennines since the 1950s

Background: High-mountain ecosystems are centres of plant diversity that are particularly sensitive to land-use and climate change.

Aims: We investigated the ecological trends associated with land use and climate change since the 1950s in different vegetation types in high-mountain habitats in the central Apennines.

Methods: We analysed temporal changes in: Pinus mugo scrub, calcareous subalpine grasslands and alpine scree vegetation, comparing historical and recent vegetation records from vegetation plots from two periods (1955–1980 and 1990–2014) for their ecological indicator values (Landolt temperature and nutrient indicators) and structural traits (growth forms) over time using generalised linear models (GLMs).

Results: We observed significant temporal differences in the ecology and structure of the analysed habitats. In the Pinus mugo scrub we detected a reduction of subalpine and herbaceous species and in calcareous alpine screes we observed an increment of the lower montane, montane and subalpine species and of dwarf shrubs. Conversely, subalpine grasslands were stable over time.

Conclusions: Ecological changes that have occurred in the Central Apennines, following changes in type and intensity of land use and recent warming are consistent with those observed in other European mountains, for which climate and land-use changes are claimed as the main driving forces.     

The impacts of increasing drought on forest dynamics,structure, and biodiversity in the United States

We synthesize insights from current understanding of drought impacts at stand‐to‐biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand‐level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, changes in composition and structure, and shifting range limits are widely observed. In the eastern US, the effects of increasing drought are becoming better understood at the level of individual trees, but this knowledge cannot yet be confidently translated to predictions of changing structure and diversity of forest stands. While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought. Throughout the continental United States, the combination of projected large climate‐induced shifts in suitable habitat from modeling studies and limited potential for the rapid migration of tree populations suggests that changing tree and forest biogeography could substantially lag habitat shifts already underway. Forest management practices can partially ameliorate drought impacts through reductions in stand density, selection of drought‐tolerant species and genotypes, artificial regeneration, and the development of multistructured stands. However, silvicultural treatments also could exacerbate drought impacts unless implemented with careful attention to site and stand characteristics. Gaps in our understanding should motivate new research on the effects of interactions involving climate and other species at the stand scale and how interactions and multiple responses are represented in models. This assessment indicates that, without a stronger empirical basis for drought impacts at the stand scale, more complex models may provide limited guidance.     

The labyrinth of nutrient cycles and buffers in wetlands: results based on research in the Camargue (southern France)

Wetlands, especially in the Mediterranean area, are subject to severe eutrophication. This may upset the equilibrium between phytoplankton production in undesirable quantities and a quantitatively desirable macrophyte production. In order to manage this equilibrium, a quantitative knowledge of nutrient input and fluxes is essential and the role of sediments in these processes must be understood. This knowledge can be useful even for agriculture, e.g. rice cultivation, where optimal utilization of fertilizers can lead to an economic benefit.In this article different aspects of nutrient cycles are discussed in view of approaching a sufficiently precise quantification. The nutrient input balance of the Camargue was therefore measured which showed that the input of nutrients with the irrigation water, taken from the river Rhone, roughly equals the quantity of fertilizers added.Phytoplankton growth can be approached reasonably with the Monod model, although there are still many practical problems, such as the influence of the pH on P uptake and the problem of measuring P uptake in the field. The situation is worse for macrophyte growth; quantitative data are scarce and studies have often been carried out with unrealistic nutrient concentrations or without addressing the influence of the sediment. This influence can also include negative factors, such as high concentrations of Fe²⁺, H₂S or FeS, but cannot yet be quantified.The nitrogen cycle in wetlands is dominated by denitrification. Most wetlands have sediments with high concentrations of organic matter, therefore with a large reducing capacity. Besides this process, we have shown that denitrification can also be controlled by FeS. In the Camargue sediments this denitrification is mediated by bacteria from the sulfur cycle; this appeared to be the major pathway. It was shown that a stoicheiometric relation exists between nitrate reduced and sulphate produced. The influence of the temperature was quantified and appeared to be stronger at high organic matter concentrations than at lower ones. Denitrification with FeS means that the bacteria use nitrate also for their N demands, while this is not necessarily the case during denitrification with organic matter.Mineralization of macrophytes is a much slower process than that of phytoplankton, probably because of their high C/N ratio. We could, however, not confirm the general assumption that the addition of nitrogen stimulates this mineralization. On the contrary, we found that two amino acids both with a C/N ratio of 6 had different mineralization rates. The amino acid composition of dead macrophytes and the C/N ratio may be of equal importance.Unlike nitrogen, phosphate is always strongly adsorbed onto sediments. The two mechanisms of the adsorption of inorganic phosphate onto sediments, i.e. the adsorption onto Fe(OOH) and the precipitation of apatite, have been quantified. The adsorption of phosphate onto Fe(OOH) can be satisfactory described with the Freundlich adsorption isotherm: P_ads = A^* (o-P)^B. The adsorption coefficient A depends on the pH of the system and the Ca²⁺ concentration of the overlying water and can be quantified preliminarily by A = a.10(^–0.416*pH).(2.86 – (1.86.e^–Ca2+)). B can be approached by 0.333, which means the cube root of the phosphate concentration. The second mechanism is the solubility of apatite. We found a solubility product of 10^–50 for hard waters. The two mechanisms are combined in solubility diagrams which describe equilibrium situations for specific lakes.The conversion of Fe(OOH) to FeS has a strong influence on phosphate adsorption, although the partial reduction of Fe(OOH) P by H₂S does not release significant quantities of phosphate. Even after complete conversion to FeS only a small part of the bound phosphate was released.Besides the two inorganic phosphate compounds, we established the existence of two organic pools, one soluble after extraction with strong acid (ASOP), the other one with strong alkali. The first pool is probably humic bound phosphate, while the larger part of the second pool was phytate. The ASOP was remineralized during the desiccation of a Camargue marsh; this drying up oxidized FeS, thus improving the phosphate adsorption and decreasing the denitrification capacity. It can, therefore, be an important tool for management. The phytate was strongly adsorbed onto Fe(OOH), which explains the non-bioavailability towards bacteria.The fact that the sediment phosphate concentration can be approached by multiplying the relevant sediment adsorption constant with % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0Jf9crFfpeea0xh9v8qiW7rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaOqaaeaaca% WGVbGaeyOeI0IaamiuaaWcbaGaaG4maaaaaaa!3B8D!\[\sqrt[3]{{o - P}}\] concentration has the consequence that much larger quantities of phosphate accumulate in the sediments than in the overlying water. This means that even if the phosphate input is stopped, the eutrophication will only be reversed very slowly, and not at all, if the shallow waters in wetlands have no through flow — as is often the case in many marshes in Mediterranean wetlands.Abbreviations used o-P = dissolved ortho phosphate (or its concentration) - N_part, P_part = particulate N or P - Tot-N_inorg = Total inorganic nitrogen (= NH₃ + NO ₂ ^– + NO ₃ ^– ) This paper, giving an overview of the research in the sediments of the Camargue, was read during the symposium Nutrient Cycles — A Joy Forever, on the occasion of my retirement, 19th of May 1993 at the I.H.E. in Delft (Netherlands).     

Effect of warming rate on the critical thermal maxima of crabs,shrimp and fish

The threat of global warming has prompted numerous recent studies on the thermal tolerance of marine species. A widely used method to determine the upper thermal limit has been the Critical Thermal Maximum (CTMax), a dynamic method, meaning that temperature is increased gradually until a critical point is reached. This method presents several advantages over static methods, however, there is one main issue that hinders interpretation and comparison of CTMax results: the rate at which the temperature is increased. This rate varies widely among published protocols. The aim of the present work was to determine the effect of warming rate on CTMax values, using different animal groups. The influence of the thermal niche occupied by each species (intertidal vs subtidal) and habitat (intertidal vs subtidal) was also investigated. CTMax were estimated at three different rates: 1 °C min⁻¹, 1 °C 30 min⁻¹ and 1 °C h⁻¹, in two species of crab, Eurypanopeus abbreviatus and Menippe nodifrons, shrimp Palaemon northropi and Hippolyte obliquimanus and fish Bathygobius soporator and Parablennius marmoreus. While there were significant differences in the effect of warming rates for some species, for other species warming rate produced no significant differences (H. obliquimanus and B. soporator). While in some species slower warming rates lead to lower CTMax values (P. northropi and P. marmoreus) in other species the opposite occurred (E. abbreviatus and M. nodifrons). Biological group has a significant effect with crabs' CTMax increasing at slower warming rates, which did not happen for shrimp and fish. Subtidal species presented lower CTMax, at all warming rates tested. This study highlights the importance of estimating CTMax values at realistic rates that species encounter in their environment and thus have an ecological value.