Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina

Overexploitation of marine communities can lead to modifications in the structure of the food web and can force organisms like elasmobranchs to change their feeding habits. To evaluate the impact that fisheries have on food webs and on the interactions between species, it is necessary to describe and quantify the diet of the species involved and follow it through time. This study compares the diet of five skate species using the data obtained from the by-catch of the Argentine hake (Merluccius hubbsi) fishery in north and central Patagonia, Argentina. Diet composition was assessed by analysing the digestive tract contents and trophic overlapping between species of the genus Bathyraja: Bathyraja albomaculata, Bathyraja brachyurops, Bathyraja macloviana, Bathyraja magellanica and Bathyraja multispinis. A total of 184 stomachs were analysed. The diets of B. albomaculata and B. macloviana mainly comprised annelids, whereas that of B. brachyurops primarily comprised fish, including hake heads discarded by the fishery. The diets of B. magellanica and B. multispinis were largely based on crustaceans. Despite the morphological similarities and their shared preference for benthic habitats, no complete diet overlaps were found between the different species. These results suggest that these skate species have undergone a process of diet specialisation. This is a common feeding strategy that occurs to successfully eliminate competition when resources are limited, which corresponds to the conditions found in an environment being affected by the pressures of overfishing.Fil: Tschopp, Ayelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Cristiani, Franco. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Garcia, Nestor Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Coscarella, Mariano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; Argentin

Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming

Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993-2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming

Mapping of mosquito (Culicidae) breeding sites using predictive geographic information methods

Application of remote sensing and other GIS methods in the subject of mapping mosquito breeding sites has not been premised accordingly. Despite the facts that the duration of field surveys would be shortened and the effectiveness of action plans would be higher with the supportance of computer modelling techniques. This work aimed to evaluate the applicability of digital elevation models and aerial photographs in the prediction of mosquito breeding sites. Relief analysis was carried out seeking depressions based on elevation models created with TIN and kriging interpolation methods. Spectral analysis was performed on aerial photographs to identify the patches of higher water content or moisture. The results show that terrain analysis can not give acceptable results due to its resolution and accuracy. Spectral analysis of normal (visible range) photographs can be a useful tool in predicting of breeding sites. On grasslands the verificitaion revealed 91% correct results

Dynamic analysis of climatic conditions for deriving suitable adaptive façade responses

Highly insulated buildings, combined with efficient HVAC systems, represent the mainstream approach to achieve low-energy buildings. However, if façades block energy exchange, the climatic resources surrounding the built environment remain untapped. Adaptive opaque façades seem promising to enhance whole building performance while reducing energy demand by their dynamic behaviour. The usual approach when defining their desired adaptive response is to test independent technologies by energy simulations, to calibrate their best adaptation range for a specific climate. Such technology-oriented approaches do rarely make a conscious analysis of the potential of local natural resources, which could lead to a weak adaptation strategy. Besides, the enhancement of combining responsive elements is usually omitted. This paper proposes a new approach for systematic analysis of dynamic climatic conditions, aiming to enable better decision-making at early design stages to ensure the proposed façade solution will have the maximum positive impact. To do so, we analysed the impact of combinations of climatic agents on the hygrothermal performance and we clustered them into Climatic Scenarios. Moreover, we examined the influence of studying not only these scenarios but also their transience. We carried out this systematic analysis for a specific temperate climate and we studied the sequences of three summer days using a screen tool that links the climate data with promising Adaptive Façade Responses. We observed how the meaningful candidate multi-responses changed in the sequence examination due to different past and future scenarios, which strengthen the need of a Dynamic Climate Analysis to properly define new adaptive façades