Spatial congruence between multiple stressors in the Mediterranean Sea may reduce its resilience to climate impacts

Climate impacts on marine ecosystems may be exacerbated by other, more local stressors interacting synergistically, such as pollution and overexploitation of marine resources. The reduction of these human stressors has been proposed as an achievable way of retaining ecosystems within a "safe operating space" (SOS), where they remain resilient to ongoing climate change. However, the operability of an SOS requires a thorough understanding of the spatial distribution of these climate and human impacts. Using the Mediterranean Sea as a case study, we illustrate the spatial congruence between climate and human stressors impacting this iconic "miniature ocean" synergistically. We use long-term, spatially-explicit information on the distribution of multiple stressors to identify those highly impacted marine areas where human stressors should be prioritized for management if the resilience to climate impacts is to be maintained. Based on our spatial analysis, we exemplify how the management of an essential supporting service (seafood provision) and the conservation of a highly impacted Mediterranean sub-region (the Adriatic Sea) may benefit from the SOS framework

Desnutrición y factores asociados en escolares: unidad educativa Froilán Segundo Méndez, San Antonio, Cañar, Ecuador, 2022

Introducción: La desnutrición se refiere a un desbalance en el estado óptimo de nutrición, y nos indica el desarrollo de una sociedad, los principales factores de la desnutrición son la inseguridad alimentaria y falta de recursos económicos. En Ecuador el 23% de la población infantil sufre desnutrición, existiendo en la provincia del Cañar un 27,2%. Objetivo: Determinar la desnutrición y sus factores asociados en niños/as entre 6 a 11 años pertenecientes a la Unidad Educativa Froilán Segundo Méndez, parroquia San Antonio de la provincia de Cañar en el año 2022. Metodología: Estudio observacional, analítico y corte transversal. Se recolectaron datos de 112 niños de 6 a 11 años, mediante aplicación de encuestas, escalas, valoración de medidas antropométricas y evaluación de factores como edad, sexo, estado socioeconómico y frecuencia del consumo de alimentos. Resultados: Se encontró una prevalencia de un 59% de desnutrición, entre los factores predisponentes se encuentran un riesgo socioeconómico alto con un 79,5%, residencia rural con un 58,3% con una frecuencia de consumo de alimentos de 5 veces al día, pero con déficit de aporte nutricional. Conclusión: Existe un aumento de desnutrición en la provincia del Cañar, el cual se encuentra duplicado a las cifras reportadas, distribuyéndose esta desnutrición equitativamente tanto en niños y niñas. El factor socioeconómico en estratos III y IV de Graffar representa riesgo de desnutrición. La mayor parte de la población de la zona rural presenta desnutrición. La frecuencia de consumo de alimentos no se encuentra asociada a desnutrición

Insights into the spatiotemporal component of feeding ecology: an isotopic approach for conservation management sciences

Aim:Bringing new approaches to trace spatiotemporal variations in animals' feeding ecology, which is fundamental for wildlife management and conservation since the accessibility of animals to trophic resources plays a key role in the dynamics of populations and metapopulations. Location:Western Mediterranean coast. Methods:The analysis of naturally occurring stable isotopes constitutes an exceptional approach to assess variations in the trophic ecology of species within the spatiotemporal dimensions. Here, we examined the spatiotemporal heterogeneity in resource exploitation of a nuisance and overpopulated gull species with a great feeding plasticity, the Yellow-legged gull Larus michahellis, by measuring the stable isotope ratios of carbon (13C/12C, delta 13C), nitrogen (15N/14N, delta 15N) and sulphur (34S/33S, delta 34S) in different wing feathers.Results:Tracing isotopic changes among feathers in relation to moulting sequence, we showed that isotopic analyses on first primary feathers were good indicators of breeding trophic ecology, while others, such as eighth secondary feathers, reflected the feeding behaviour during the non-breeding period. This knowledge was then used to report on estimations of seasonal feeding patterns throughout the year for seven gull populations along the Western Mediterranean coast. Main conclusions: The high diversity in the exploitation patterns of the foraging habitats found in the study area both at spatial and at temporal scale indicated the opportunistic feeding behaviour of Yellow-legged gulls. Proposed isotopic approach has revealed as a useful tool to evaluate spatiotemporal variations in the feeding ecology of populations which may become clue for dealing with the management of wild species, not only nuisance populations but also endangered species. We finally pointed out the relevance of the isotopic variability among individuals to infer diet diversity and food availability of a given population, thereby allowing demographic forecasts when trophic resources vary in abundance

Using a three-isotope Bayesian mixing model to assess the contribution of refuse dumps in the diet of the yellow-legged gull Larus michahellis

SUMMARY.¿ The yellow-legged gull Larus michahellis is usually considered as an opportunistic species that depends on food derived from anthropogenic activity, such as garbage and fishery discards. However, although it has become a problematic species in many Mediterranean countries, there is stillno information about its status in Tunisia. The aim of this work was to assess the differential use of marine and terrestrial resources by the yellow-legged gulls breeding in an urban area on Chikly Island. Dietary reconstructions were performed through the analysis of regurgitates and δ13C, δ34S and δ15N of feathers of fledglings. Contrary to most Mediterranean breeding colonies, and to our expectations, the mixing model showed that yellow-legged gulls from Chikly are above all marine foragers. Whereas the Lake of Tunis was the principal source of food in 2005 and 2007, chicks from 2006 were fed mainly with prey from the Gulf of Tunis. Although the Gulf is located further from the breeding colony and has less fishing activity than the Lake, our study demonstrated that it is used as an alternative foraging habitat. The Bayesian mixing model approach proved to be a useful tool for evaluating temporal variations in the feeding ecology of the colony, which is relevant information in the management of a wild species. This study also demonstrated the importance of isotopic variability among years for inferring diet diversity and food availability for the colony, thereby allowing demographic forecasts when trophic resources vary in abundance or the foraging habitat is disturbed

Humans shape the year-round distribution and habitat use of an opportunistic scavenger

Research focused on evaluating how human food subsidies influence the foraging ecology of scavenger species is scarce but essential for elucidating their role in shaping behavioral patterns, population dynamics, and potential impacts on ecosystems. We evaluate the potential role of humans in shaping the year-round distribution and habitat use of individuals from a typical scavenger species, the yellow-legged gull (Larus michahellis), breeding at southwestern Spain. To do this, we combined long-term, nearly continuous GPS-tracking data with spatially explicit information on habitat types and distribution of human facilities, as proxied by satellite imagery of artificial night lights. Overall, individuals were mainly associated with freshwater habitats (mean proportion, 95% CI: 40.6%, 36.9%-44.4%) followed by the marine-related systems (40.3, 37.7%-42.8%), human-related habitats (13.5%, 13.2%-13.8%), and terrestrial systems (5.5%, 4.6%-6.5%). However, these relative contributions to the overall habitat usage largely changed throughout the annual cycle as a likely response to ecological/physiological constraints imposed by varying energy budgets and environmental constraints resulting from fluctuations in the availability of food resources. Moreover, the tight overlap between the year-round spatial distribution of gulls and that of human facilities suggested that the different resources individuals relied on were likely of anthropogenic origin. We therefore provide evidence supporting the high dependence of this species on human-related food resources throughout the annual cycle. Owing to the ability of individuals to disperse and reach transboundary areas of Spain, Portugal, or Morocco, international joint efforts aimed at restricting the availability of human food resources would be required to manage this overabundant species and the associated consequences for biodiversity conservation (e.g., competitive exclusion of co-occurring species) and human interests (e.g., airports or disease transmission)

Stable isotopes (δ13C, δ15N) combined with conventional dietary approaches reveal plasticity in central-place foraging behaviour of little penguins Eudyptula minor

Marine top and meso predators like seabirds are limited by the need to breed on land but forage on limited or patchily distributed resources at sea. Constraints imposed by such central-place foraging behavior change during breeding or even disappear outside the breeding period when there is no immediate pressure to return to a central place. However, central place foraging is usually factored as an unchanging condition in life history studies. Here we used little penguin Eudyptula minor, a resident bird with one of the smallest foraging range among seabirds, to examine the different degree of pressure/constraints of being a central-place forager. We combined data on isotopic composition (δ13C and δ15N), conventional stomach contents and body mass of little penguins breeding at Phillip Island, Australia over 9 years (2003-2011). We explored relationships between diet and body mass in each stage of the breeding season (pre-laying, incubation, guard, and post-guard) in years of 'high' and 'low' reproductive success. Values of δ13C and δ15N as well as isotopic niche width had similar patterns among years, with less variability later in the season when little penguins shorten their foraging range at the expected peak of their central-place foraging limitation. Body mass peaked before laying and hatching in preparation for the energetically demanding periods of egg production and chick provisioning. An increase of anchovy and barracouta in the diet, two major prey for little penguins, occurred at the critical stage of chick rearing. These intra-annual trends could be a response to imposed foraging constraints as reproduction progresses, while inter-annual trends could reflect their ability to match or mismatch the high energy demanding chick rearing period with the peak in availability of high-quality prey such as anchovy. Our findings underline the key advantages of using a stable isotope approach combined with conventional dietary reconstruction to reveal an otherwise intractable ecological issue of different constrains of being a central-place forager, such as the little penguin, which could be applied to other marine species

Adapting to a changing world: Unraveling the role of man-made habitats as alternative feeding areas for Slender-billed Gull (Chroicocephalus genei)

Current rates of wildlife habitat loss have placed increasing demands on managers to develop, validate and implement tools aimed at improving our ability to evaluate such impacts on wildlife. Here, we present a case study conducted at the Natural Area of Doñana (SW Spain) where remote sensing and stable isotope (δ13C, δ15N) analyses of individuals were combined to unravel (1) the effect of variations in availability of natural food resources (i.e. from natural marshes) on reproductive performance of a Slender-billed Gull (Chroicocephalus genei) population, and (2) the role of two adjacent, artificial systems (a fish farm and saltmines) as alternate anthropogenic feeding areas. Based on long-term (1983-2004) remote-sensing, we inferred the average extent of flooded area at the marshland (a proxy to natural resource availability) annually. Estimated flooded areas (ranging from extreme drought [ca. 151 ha, 1995] to high moisture [15,049 ha, 2004]) were positively related to reproductive success of gulls (estimated for the 1993-2004 period, and ranging from ca. 0 to 1.7 fledglings per breeding pairs), suggesting that habitat availability played a role in determining their reproductive performance. Based on blood δ13C and δ15N values of fledglings, 2001-2004, and a Bayesian isotopic mixing model, we conclude that saltmines acted as the main alternative foraging habitat for gulls, with relative contributions increasing as the extent of marshland decreased. Although adjacent, anthropogenic systems have been established as the preferred breeding sites for this gull population, dietary switches towards exploitation of alternative (anthropogenic) food resources negatively affected the reproductive output of this species, thus challenging the perception that these man-made systems are necessarily a reliable buffer against loss of natural feeding habitats. The methodology and results derived from this study could be extended to a large suite of threatened natural communities worldwide, thus providing a useful framework for management and conservation

Evolutionary Feature Selection for Big Data Classification: A MapReduce Approach

Nowadays, many disciplines have to deal with big datasets that additionally involve a high number of features. Feature selection methods aim at eliminating noisy, redundant, or irrelevant features that may deteriorate the classification performance. However, traditional methods lack enough scalability to cope with datasets of millions of instances and extract successful results in a delimited time. This paper presents a feature selection algorithm based on evolutionary computation that uses the MapReduce paradigm to obtain subsets of features from big datasets. The algorithm decomposes the original dataset in blocks of instances to learn from them in the map phase; then, the reduce phase merges the obtained partial results into a final vector of feature weights, which allows a flexible application of the feature selection procedure using a threshold to determine the selected subset of features. The feature selection method is evaluated by using three well-known classifiers (SVM, Logistic Regression, and Naive Bayes) implemented within the Spark framework to address big data problems. In the experiments, datasets up to 67 millions of instances and up to 2000 attributes have been managed, showing that this is a suitable framework to perform evolutionary feature selection, improving both the classification accuracy and its runtime when dealing with big data problems.This work is supported by the Research Projects TIN2014-57251-P, P10-TIC-6858, P11-TIC-7765, P12-TIC-2958, and TIN2013-47210-P. D. Peralta and S. Ramírez-Gallego hold two FPU scholarships from the Spanish Ministry of Education and Science (FPU12/04902, FPU13/00047). I. Triguero holds a BOF postdoctoral fellowship from the Ghent University

Foraging in the Anthropocene: Feeding plasticity of an opportunistic predator revealed by long term monitoring

For centuries, human activities have altered the population dynamics of wildlife. New anthropogenic food sources provide a predictable and abundant food supply that often induces very significant changes in the size, distribution, and behaviour of many populations, with ultimate consequences on the structure and functioning of natural ecosystems. Here, we combine historical and contemporary feather samples of a population of a superabundant, opportunistic predator, the yellow-legged gull Larus michahellis, to assess its trophic ecology and relate it to human activities in the long term. Dietary assessments were based on stable isotope analysis of carbon, nitrogen, and sulphur (δ13C, δ15N and δ34S), and were conducted through three end-point (marine prey, waste from landfills-slaughterhouses, and terrestrial invertebrates) Bayesian mixing models. Our results suggest that gulls' diet showed a progressive decrease in the consumption of marine prey throughout the most recent period (late 20th century onwards), linked to an increase in the consumption of meat waste and small terrestrial invertebrates. Reported dietary changes over the sampling period correlated positively with the availability of marine resources around the breeding area. We provide evidence suggesting that the ability of gulls to exploit efficiently diverse anthropogenic food subsidies likely resulted in the exponential demographic increase of this population throughout the 20th century. In addition, current regulations affecting the availability of these food resources (e.g., fishing discards and landfill waste) likely reversed this trend over the last decade. Long-term evidence of population trophic plasticity, like the one we present here, is essential to implement and support management and conservation actions that limit the availability of anthropogenic resources, especially when it comes to superabundant, problematic species

Sea ice phenology and primary productivity pulses shape breeding success in Arctic seabirds

Spring sea ice phenology regulates the timing of the two consecutive pulses of marine autotrophs that form the base of the Arctic marine food webs. This timing has been suggested to be the single most essential driver of secondary production and the efficiency with which biomass and energy are transferred to higher trophic levels. We investigated the chronological sequence of productivity pulses and its potential cascading impacts on the reproductive performance of the High Arctic seabird community from Svalbard, Norway. We provide evidence that interannual changes in the seasonal patterns of marine productivity may impact the breeding performance of little auks and Brünnich's guillemots. These results may be of particular interest given that current global warming trends in the Barents Sea region predict one of the highest rates of sea ice loss within the circumpolar Arctic. However, local- to regional-scale heterogeneity in sea ice melting phenology may add uncertainty to predictions of climate-driven environmental impacts on seabirds. Indeed, our fine-scale analysis reveals that the inshore Brünnich's guillemots are facing a slower advancement in the timing of ice melt compared to the offshore-foraging little auks. We provide a suitable framework for analyzing the effects of climate-driven sea ice disappearance on seabird fitness