Articles publicats en revistes (Biologia Evolutiva, Ecologia i Ciències Ambientals)

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Five centuries of lake deoxygenation and microbial shifts revealed by sedimentary DNA
(Elsevier, 2026-03-01) Vegas Vilarrúbia, Teresa Elena; Sacristán Soriano, Oriol; Borrego, Carles M.; Corella, Juan Pablo; Errea, Paz; Buchaca, Teresa; Rull, Valentí
Expanding global deoxygenation is a major ecological crisis. Oxygen loss in aquatic systems is reshaping ecosystems, altering biodiversity, nutrient cycles, and ecosystem functioning. Microbial communities, as key biogeochemical mediators, are highly responsive to oxygen availability, yet their long-term trajectories under sustained oxygen loss remain poorly understood. This limits our ability to anticipate ecosystem responses to climate-driven deoxygenation. We reconstructed five centuries of microbial and oxygen dynamics in meromictic Lake Montcortès (southern Pyrenees) using sedimentary deoxyribonucleic acid (DNA) and X-ray fluorescence spectroscopy of varved sediments. Average volume of anoxic water (VAW) increased from 545,560 m³ in the preindustrial period (1500–1750 Common Era) to 558,692 m³ after 1905, with greater persistence from 1937 onward. Instrumental data (2013–2020) confirmed this trend, with VAW peaking at 1018,400 m³ and anoxia reaching 11.5 m and anoxia occurring below 11.5 m depth. Microbial communities gradually shifted from suboxic-adapted taxa to anaerobic assemblages dominated by sulfate-reducing bacteria and methanogenic archaea, reflecting historical anthropogenic pressures and recent warming-driven anoxia. Despite compositional change, core functional traits persisted, with no evidence of abrupt regime shifts indicating microbial resilience under long-term redox stratification. The timing of stratification intensification in Lake Montcortès coincides with the mid-20th century onset of the Anthropocene, as defined by the Anthropocene Working Group. Its annually resolved varved sediments, combined with clear geochemical and microbial signals of anthropogenic impact, support its proposal as a candidate Global Boundary Stratotype Section and Point Global (GSSP or “golden spike”).
Detecting community assembly filters in urban butterflies through analyses of non-Gaussian trait distributions
(Wiley, 2026-12-01) Melero Cavero, Yolanda; Stefanescu, Constanti; García-Callejas, David
The distributions of ecological traits are commonly used to infer the processes structuring ecological communities, as these processes (deterministic or neutral) select and filter species, leading to distinct trait patterns across communities. Trait distributions are frequently characterised by their average, the community-weighted mean, but increasing evidence exists for non-Gaussian trait distributions in empirical communities. In such situations, community-weighted means are insufficient to capture the patterns of community traits and to infer the implied ecological processes.We analysed the empirical distributions of six functional traits of butterflies from a natural community and a filtered community from an urban area across 6 years.All trait distributions were non-Gaussian, asymmetrical, with relatively long tails (high values of skewness and kurtosis) and multimodal. Results indicate the co-dominance of some trait values, while others rarely occur, and clear differences between the natural and filtered communities; patterns are only adequately described via statistical descriptors beyond community-weighted means. Our analyses allowed us to infer that the filtered community is shaped by a mixture of directional and stabilising assembly filters. The consistent results across the 6 years of data provided further evidence of deterministic processes shaping the assembly of our urban community.Overall, we provide evidence of the ubiquity of non-Gaussian trait distributions across natural and filtered communities, combine multiple statistical descriptors for understanding and comparing such distributions and identify filtering processes structuring these communities.
Insights from stable isotope and fatty acid analyses on the diet of an Antarctic nudibranch
(Inter-Research, 2024-12-05) De Castro Fernández, Paula; Giménez, Joan; Ávila Escartín, Conxita; Cardona Pascual, Luis
Reconstructing predator-prey interactions in a biological community provides a better understanding of species’ ecological roles and helps predict how changes in one component will affect the others. Doris kerguelenensis is an Antarctic heterobranch mollusc that feeds on sponges, according to previous gut content analyses. Here, stable isotopes of carbon and nitrogen (δ 13C and δ15N) and fatty acids (FAs) were used to assess the relative contribution of several species of demosponges (Axinella crinita, Dendrilla antarctica, Hemigellius pilosus, Kirkpatrickia variolosa, Mycale acerata, Sphaerotylus antarcticus, and Haliclona sp.) to D. kerguelenensis diet. Particulate organic matter and 2 macroalgae species were also analyzed to better characterize the diversity of sources fueling the food web. The δ15N values of the sponges suggest a trophic position of 2-3 for A. crinita, D. antarctica, M. acerata, and Haliclona sp. and of 3-4 for H. pilosus and S. antarcticus. Mixing models failed to resolve the nudibranch diet, either because the sponges were too enriched in 13C or because the diet-to-tissue discrimination factor values available in the literature for gastropods are unsuitable for this nudibranch species. The high abundance of bacterial FA markers in H. pilosus, S. antarcticus, and K. variolosa, and their high δ15N values, rule them out as major prey for D. kerguelenensis. The overall evidence suggests that A. crinita, D. antarctica, M. acerata, and Haliclona sp. are consumed regularly by D. kerguelenensis but do not represent its only dietary sources. Hence, the analysis of biomarkers refutes the previously established role of D. kerguelenensis as a specialized spongivore.
Effects of the invasive riparian plant Arundo donax on riverine fish: a call for action?
(Elsevier B.V., 2025-07-30) Maceda Veiga, Alberto; Colin, Nicole; Mac Nally, Ralph; Salvadó i Cabré, Humbert; Sostoa Fernández, Adolfo de; Yen, Jian D.L.
Studies that investigate the effects of a given invasive exotic species within real-world contexts are essential for informing effective management decisions. Here, we used extensive surveys of stream reaches in north-eastern Spain to test whether the presence of the widely distributed invasive exotic riparian plant Arundo donax is detrimental to the conservation of riverine fishes. To explore potential impacts of A. donax at different temporal scales, we examined fish responses using indicators of relatively recent effects (body-condition index) and longer lasting effects (functional diversity indices, taxonomic richness, and the relative abundance of 12 fish species). We found correlative evidence for net positive effects of the presence of A. donax on native fish richness and body condition but negative effects on the overall functional diversity of fish assemblages, including invasive exotic and translocated native fish species. Our analyses also revealed significant interactions between A. donax and local stream conditions, suggesting that these net effects of the plant on fish might shift in direction in some circumstances. In particular, several indicators at the fish community scale support that the presence of A. donax may be beneficial to fishes in streams with high Strahler order values, in-stream habitat diversity and lack of channelization. The plant may provide shelter and refugia to fish in these medium, low-land Mediterranean streams with typically poor cover of high riparian vegetation. Therefore, without overlooking the serious threats caused by biological invasions, this study illustrates that, at least under specific environmental conditions, the local removal of A. donax alone may not achieve the desired ecological outcomes if pre-existing fish-habitat relationships are not taken into account.
The Interplay of Climate Change, Urbanisation, and Species Traits Shapes European Butterfly Population Trends
(John Wiley & Sons, 2026-02-06) Colom, Pau; Tejeda, Ashley; Bonelli, Simona; Fontaine, Benoît; Kuussaari, Mikko; Maes, Dirk; Mestdagh, Xavier; Munguira, Miguel L.; Musche, Martin; Pettersson, Lars B.; Roy, David; Rüdisser, Johannes; Šašić, Martina; Schmucki, Reto; Stefanescu, Constanti; Titeux, Nicolas; Settele, Josef; van Swaay, Chris; Gordillo, Javier; Melero Cavero, Yolanda
Aim: To examine how butterfly population trends respond to climate change and urbanisation at a continental scale, and whether responses differ between urban and rural environments. Location: 869 sites across 12 European countries, spanning six bioclimatic zones. Time Period: 1976–2021. Major Taxa Studied: Butterflies (Lepidoptera). Methods: We analysed long-term monitoring data from > 8400 populations of 145 species representing a wide range of ecological and life-history traits. Population trends were modelled in relation to climate variables (temperature, precipitation and aridity), urbanisation (built-up surface), and their interactions with urban context (urban vs. rural) and species traits (trophic specialisation, body size, reproductive rate and thermal adaptation). Results: Climate warming and aridification were consistently linked to population declines in both rural and urban contexts, while precipitation effects varied by location and species. Urbanisation alone did not predict trends, but the urban–rural context strongly modulated species' responses to warming, indicating potential synergies between climate change and urbanisation. The stronger impact of warming in urban populations likely reflects elevated baseline temperatures and reduced habitat suitability and connectivity in urban landscapes, limiting thermal buffering. Species with colder thermal niches and lower reproductive rates were most vulnerable to warming, as warming exceeds the thermal optima of cold-adapted species and lower reproductive rates limit their capacity to buffer climate-driven population declines. Under aridification, which can reduce host-plant availability, trophic specialists declined more in urban areas, whereas generalists unexpectedly declined more in rural sites, suggesting context-dependent constraints under increasing water limitation. Main Conclusions: Our findings highlight the complex interplay between climate change, urban context, and species traits in driving population dynamics. Importantly, our results suggest that urbanisation generally amplifies the negative impact of climate change on insect population trends.
Plastic exposure risk for costal seabirds varies seasonally with freshwater runoff
(Elsevier B.V., 2025-03) Garcia-Garin, Odei; Burzón, Mireia; Cardona Pascual, Luis; Ramos Lobo, Raúl
Marine litter, including Floating Marine Macro-Litter (FMML) and microplastics (MP), poses a major threat to marine ecosystems. This study investigates the seasonal distribution of FMML and MP in the Ebro Delta, a key Mediterranean wetland, and evaluates the potential risk to three tern species (family Laridae, subfamily Sterninae) that rely on the area for foraging and breeding. Seasonal surveys (October 2021–June 2022) were conducted using drone and manta trawl sampling for litter assessment, with tern densities estimated via distance sampling. Results revealed seasonal peaks in FMML and MP densities, with the highest concentrations in autumn and spring, likely influenced by river discharge and irrigation runoff. Risk assessment maps identified high-risk zones where tern densities overlapped with FMML and MP hotspots, indicating potential threats from entanglement, ingestion, and trophic transfer of pollutants. These findings underscored the relevance of seasonality and spatial risk assessment when evaluating exposure to marine litter. This study not only enhanced our understanding of marine litter impacts in the Mediterranean Sea but also provided essential data to inform evidence-based policies and management strategies aimed at protecting vulnerable species in this ecologically relevant area.
Surface waters meso- and micro-litter around the Western Antarctic Peninsula: Are the South Shetland Islands a pollution hotspot?
(Elsevier, 2025-08-08) Monràs i Riera, Pere; Ruiz Orejón, Luis Francisco; Angulo-Preckler, Carlos; Sardá, Rafael; Ávila Escartín, Conxita
Not even the most remote and pristine oceanic regions, such as the Southern Ocean, are immune to the impacts of marine litter. This study presents novel data on surface waters meso- and micro-litter along the Western Antarctic Peninsula and Livingston Island (South Shetland Islands) across two summer campaigns (2022–2023), providing one of the broadest assessments of marine debris in Antarctica (62° S to 67° S). Litter was detected at all sampling sites, with abundances ranging from 0.019 ± 0.033 to 0.193 ± 0.104 items m−3 along the Western Antarctic Peninsula (average: 0.086 ± 0.082 items m−3). The South Shetland Islands exhibited significantly higher litter abundances compared to higher-latitude sites. Our results show that litter distribution correlates with human activity intensity, with latitude and the personnel density of nearby research stations as key influencing factors. The South Shetland Islands emerged as an Antarctic marine litter hotspot, likely driven by the concentration of Antarctic facilities and other anthropogenic activities. Litter was primarily composed of synthetic fibres, especially polyester and nylon, pointing to local human sources. Additionally, a decrease in marine litter was observed at Livingston Island between campaigns, with abundance declining from 0.235 ± 0.152 items m−3 to 0.116 ± 0.033 items m−3. This highlights the need for ongoing monitoring to capture interannual variability, avoid seasonal biases, and better understand marine litter dynamics in the Southern Ocean to guide conservation efforts. These findings underscore human impact in Antarctica and the urgent need for better waste management and stricter environmental regulation enforcement.
Micro-litter pollution in the ascidian Cnemidocarpa verrucosa along the Antarctic Peninsula
(Elsevier B.V., 2025-08-25) González Pineda, Mariona; Salvadó i Cabré, Humbert; Monràs i Riera, Pere; Ávila Escartín, Conxita
Antarctic benthic ecosystems are currently threatened by global change and direct human impact. Pollution fromlocal human activities is among the most relevant emerging hazards affecting Antarctic organisms. Micro-litter(ML) has already been found in Antarctic marine ecosystems, including diverse benthic fauna. This studycharacterised and quantified ML in a common soft-bottom filter-feeding solitary ascidian, Cnemidocarpa verrucosa(Lesson, 1830), along the Antarctic Peninsula from 62◦ S to 67◦ S, focusing particularly on Deception Island.Study sites included Johnsons’ Bay (Livingston Island), Deception Island (South Shetland Islands), Uruguay Island(Yalour Islands), and Ryder Buttress (Ryder Bay, Adelaide Island). More than half of the analysed organismscontained at least one ML particle, with an average of 0.14 ± 0.26 items per gram (viscera wet weight) and 1.62± 1.79 items per individual. Microplastics represented 37 % of the total ML items found. Along the AntarcticPeninsula, significantly higher amounts of ML were found in Johnsons’ Bay and Uruguay Island. WithinDeception Island, significantly higher ML abundances were found in Murature, at the innermost part of the island.The most common items found were black or blue cellulosic fibres within the smallest size range analysed(100–500 μm). We suggest that variations in ML among sites could be mainly due to the different intensity ofanthropogenic activities, although environmental characteristics of the locations (i.e. currents, bottom type) alsoplayed a key role in its distribution. To the best of our knowledge, this is the first study to assess ML pollution inan Antarctic ascidian and it also represents the southernmost benthic invertebrate study regarding ML along theAntarctic Peninsula. We believe this research may contribute to the development of policies to protect theAntarctic marine benthos from human pollution and improve their management.
Stranded beach debris in the West Antarctic Peninsula: Quantification anddistribution of marine litter
(Elsevier B.V., 2025-05-01) Monràs i Riera, Pere; Lozoya, Juan Pablo; Teixeira de Mello, Franco; Ávila Escartín, Conxita
Marine debris, particularly plastics, is a growing threat to global marine ecosystems, including remote regions like the Southern Ocean. This study presents one of the most extensive surveys of beached marine debris along the West Antarctic Peninsula, covering 31 beaches from 62° S to 67° S, the widest latitudinal range in Antarctica. Our results reveal the prevalence of stranded debris, with plastics as the main pollutant. Higher debris densities were observed near research stations, with Esperanza Bay (9.26·10−1 items m−2) and Cierva Cove (5.56·10−2 items m−2) beaches exhibiting significant pollution levels. We observed a concentration of debris at lower latitudes, particularly around the South Shetland Islands, due to intense anthropogenic activity. Furthermore, we compared the plastic litter between two islands with distinct geomorphology: Livingston Island, an open system influenced by oceanic currents, and Deception Island volcanic cone, an enclosed system sheltered from such dynamics. These revealed that Livingston Island showed higher densities of plastics related to food usage, which were larger, heavier, and predominantly composed of polyester, mostly drifting plastics associated with maritime sources. In contrast, the volcanic cone of Deception Island, sheltered from the ocean, predominantly contained plastics with an undefined use, which were smaller, lighter, and primarily made of polystyrene and polyethylene, suggesting debris of local origin. The study highlights the influence of both human activities and ocean dynamics on debris distribution, underscoring the need for improved waste management and international regulations. These findings provide a baseline for future research and policy development to preserve Antarctica's fragile ecosystems.
Insights into the trophic ecology of white-beaked dolphins (Lagenorhynchus albirostris) and harbour porpoises (Phocoena phocoena) in Icelandic.
(Inter-Research, 2022-12-08) Samarra, Filipa I. P.; Borrell Thió, Assumpció; Selbmann, Anna; Halldórson, Sverrir D.; Pampoulie, Christophe; Chosson, Valérie; Gunnlaugsson T.; Aguilar, Àlex; Víkingsson Gísli A.; Sigurðsson, Guðjón M.
Sympatric organisms can avoid competition by occupying different ecological niches, a mechanism known as niche partitioning. In Iceland, white-beaked dolphins Lagenorhynchus albirostris and harbour porpoises Phocoena phocoena are the most common small cetaceans observed but their trophic ecology remains understudied, including the potential for resource competition. In this study, we measured δ15N and δ13C values from white-beaked dolphin (n = 28) and harbour porpoise (n = 29) muscle samples collected over a 33 yr period (1987−2019) to compare isotopic niche width and overlap of both species, as well as diet composition. We also tested for within-species effects of sex, age class, body length, year of sampling and origin (bycatch vs. stranding) on the δ13C and δ15N values. Intra-species variations included differences between stranded and bycaught white-beaked dolphins and ontogenetic variations in both species, but further studies are necessary to investigate the factors that might explain these results. Inter-species comparisons showed that harbour porpoises and white-beaked dolphins had non-overlapping isotopic niches, with harbour porpoises exhibiting smaller niche widths (corrected standard ellipse area, SEAc: 1.25 vs. 2.13¿2). While white-beaked dolphins had a broader diet, composed primarily of gadoids but with contributions of other fish species, harbour porpoises fed almost exclusively on capelin Mallotus villosus, suggesting niche segregation and width is largely maintained by targeting different prey resources. Both species also showed no long-term changes in trophic ecology, despite recent ecosystem changes in this region, possibly a result of adapting to spatial changes in prey distribution or shifts to other prey at similar trophic levels.
Alkenone Uk’37 index differs between thermally separated populations of fin whales and krill.
(Inter-Research, 2023-12-21) Rita, Diego; Borrell Thió, Assumpció; Víkingsson, Gísli; Aguilar, Àlex
Although habitat temperature is an important determinant of species distributions, its measurement is difficult in mobile marine organisms. Chemical tracers such as alkenones constitute an alternative tool for gauging marine habitat temperature, something particularly relevant in the current scenario of global warming. The unsaturation index of alkenones, the Uk’37 index, can be used to estimate sea surface temperature (SST) in living organisms. Here, we analyse alkenone concentrations in a predator species, the fin whale, and its prey, the northern krill, both sampled in 2 areas with different SSTs: SW Iceland and NW Spain. In NW Spain (but not in SW Iceland), alkenone concentrations were higher in krill than in fin whale blubber, suggesting that they may biodilute along the trophic transfer. Consistently with local SST, the Uk’37 index was lower in the Icelandic samples of both fin whales and krill than in those from NW Spain, confirming the ability of this index to distinguish populations that are thermally separated. Whales are migratory animals; thus, the alkenones present in their blubber are a mix of those ingested locally and in recently visited regions. Consistently, the Uk’37 index showed a higher correlation with the local SST in krill than in fin whales. Alkenone turnover rates should be considered when using this proxy to assess the thermal range of the feeding habitat of a species. We conclude that the Uk’37 index is a potentially efficient tool to study the behaviour of whales, thus providing an alternative perspective to other chemical tracers.
Sulfur stable isotope ratios provide further insight into movements of the fin whale, an oceanic long-range migrant.
(Inter-Research, 2022-09) García-Vernet Raquel; Aguilar, Àlex; Zafra, Julia; Víkingsson, Gísli; Halldórsson, Sverrir Daniel; Borrell Thió, Assumpció
Stable isotope ratios have proven a valuable tool to investigate marine mammal ecology, including diet of species, distribution and migratory movements. While most studies have focused on δ 15 N and δ 13 C values, knowledge on the sources and tissue dynamics of δ 34 S values is still very limited. We examined the sequential variation of δ 15 N, δ 13 C and δ 34 S values along the baleen plates from fin whales occurring off W Iceland in summer. All baleen plates exhibited fluctuations along their growing axis. A significantly synchronic correlation was found between δ 15 N and δ 34 S values, while the relation of these values with δ 13 C was highly variable and inconsistent. These results were similar to those from previous studies in Greenland bowhead whales, although the periodicity of the oscillations was reversed. Although seasonal variations in food intake and the associated cycles of protein synthesis and catabolism, may have played a role in such fluctuations and the observed differences between species, we suggest that the main driver for the δ 15 N and δ 34 S fluctuations reflected in baleen plates is the variation of local baselines between winter and summer grounds. This offers great potential for using δ 34 S values to study migratory movements and destinations provided that the actual patterns of geographic variation of such values are clarified.
When oil companies race to the bottom: Environmental enforcement in theory and corporate impunity in practice in the Peruvian Amazon
(Elsevier, 2025-11-17) Rius-Taberner, Guillem; Pellegrini, Lorenzo; Muñoa, Gorka; Orta-Martínez, Martí
Over the past two decades, Latin American States have adopted laws and created institutions to oversee the activities of transnational extractive companies. Despite these efforts, scholars argue that companies routinely breach environmental regulations and face little consequences. This study employs a case study of oil blocks 1AB/192 and 8 to examine how environmental enforcement operates in practice. Drawing on data from the Peruvian Environmental Assessment and Enforcement Agency (OEFA) and a locally-run indigenous participatory monitoring system, we find that only 34 % of 1184 identified impacts were inspected, with sanctions applied in 17 % of cases. Even then, corrective measures were poorly implemented, and fines were often unpaid. We show how corporate actors exploit appeals and liquidation strategies to evade accountability. These findings highlight the structural weaknesses of Peru's enforcement system and underscore the need for multi-scalar response involving stronger institutional capacity, integration of Indigenous monitoring, and international legal reforms that address structural conditions enabling corporate impunity.
Efecte de la freqüentació del bestiar en la biodiversitat i l’estat de conservació dels hàbitats pradencs subalpins als Pirineus Centrals
(Departament de Geografia, 2026-07-14) Anadon Rosell, Alba; Grau Fernàndez, Oriol; Casado-Pérez, Josep; Casas, Carme; Ninot i Sugrañes, Josep Maria; Pérez Haase, Aaron; Pladevall Izard, Eulàlia; Salvat, Andreu; Vidal-Cardos, Roger; Illa, Estela; Àlvarez-Bellido, Aina
En aquest estudi hem analitzat l’efecte de la freqüentació del bestiar en tres tipus de pratsnsubalpins majoritaris als Pirineus centrals catalans, dominats per Agrostis capillaris, Nardus stricta o Festuca eskia. Per a cada tipologia de prat, vam seleccionar cinc localitats on disposàvem de dades del moviment dels ramats a través de collars amb GPS, i en base a les quals vam establir cinc parcel·les en situacions representatives de diferents nivells de freqüentació ramadera: matollar, prat emmatat, prat poc freqüentat, prat molt freqüentat i pleta. En cada parcel·la vam fer un inventari florístic i en vam avaluar l’estat de conservació a partir de dos protocols contrastats. Els resultats obtinguts mostren com els ambients sotmesos a una pressió moderada del bestiar són els més rics i amb un estat de conservació millor, mentre que les zones sense pastura o intensament freqüentades són les més pobres i més homogènies florísticament.
Climatic resilience to fire of the woody understory in Mediterranean seederand resprouter-dominated forests
(Elsevier B.V., 2026-08-11) Codina, Gerard; Lloret Maya, Francisco; Tovar-Rodríguez, Adriana; Perez-Navarro, Maria Angeles; Margalef-Marrase, Jordi; Batllori Presas, Enric
Fires can reshape Mediterranean forests and landscapes, yet their role in modifying the climatic disequilibrium (CD) of post-fire understory communities, quantified as the difference between species’ climatic optimum and the observed climate, remains unclear. We assessed whether wildfires alter the CD of woody understory communities in forests dominated by two Mediterranean tree species with contrasting regeneration strategies: Pinus halepensis, a post-fire seeder, and Quercus ilex, a resprouter. We used burned plots from the Spanish National Forest Inventory sampled before and after fire, selecting forests clearly dominated by either species and burned once between the two most recent inventories. CD was quantified as the Euclidean distance between observed climate and community-inferred climate. We compared CD before and after fire, assessed changes in woody understory composition, and analyzed the influence on CD changes of fire severity, time since fire, CD peaks, regeneration traits, and forest structure. Q. ilex understories showed higher CD than P. halepensis understories, and wildfires did not significantly modify understory CD in either forest type, although the mechanisms underlying this stability differed. In P. halepensis forests, fire markedly altered understory composition, but post-fire regenerating species had similar climatic preferences. In Q. ilex forests, understory composition showed little post-fire variation, reflecting species persistence. Pre-fire climatic conditions were most relevant in explaining understory CD in P. halepensis forests, whereas forest structure was the most relevant factor in Q. ilex forests. Results suggested that Mediterranean understories are climatically resilient after fire, maintaining CD through compositional persistence or turnover among climatically similar species.
When blue meets green: Behavioural patterns and social lingering around naturalised ponds in Barcelona
(Elsevier GmbH, 2026-11) Valera, Sergi; Castrechini Trotta, Ángela; Schiller Calle, Daniel von
Against the dual challenges of climate vulnerability and biodiversity loss, naturalising urban spaces has emerged as a key nature-based solution for dense Mediterranean cities. This study examined behavioural patterns in urban blue and green spaces, focusing on the presence and influence of naturalised pond environments in public parks. Using a multidimensional systematic observational approach, data were collected from four parks in Barcelona, Spain, each comprising a blue-space area containing a naturalised pond and a nearby green-space area without a pond. Network analysis revealed that green spaces were primarily associated with walking through passage zones, involving both individuals and groups. Blue spaces also supported common activities such as walking and conversing but were additionally associated with distinctive water-related behaviours, including contemplation, interaction with the water, and photography. These activities were predominantly group-based, suggesting that ponds functioned as focal points for social and recreational use. Behaviours associated with lingering accounted for 51.7% of activities in blue spaces, compared with 32.2% in green spaces. These findings indicate that urban blue spaces broaden the range of activities supported by urban parks and are associated with a greater prevalence of social, recreational, and lingering-related behaviours. Incorporating naturalised water features into urban parks may therefore contribute to more engaging and socially supportive public spaces, with potential benefits for community interaction and human well-being.
Relationship between the female attendance pattern and pup growth rate in the South American sea lion (Carnivora)
(Consejo Superior de Investigaciones Científicas (CSIC), 2021) Drago, Massimiliano; Cardona Pascual, Luis; Franco-Trecu, Valentina; Riet-Sapriza, Federico G.; Crespo, Enrique A.; Garcia Garcia, Nuria; Inchausti, Pablo
Changes in the duration and frequency of foraging trips by female otariids may result in changes in the duration and frequency of lactation bouts and hence influence pup growth rate, unless females modify milk energy density and/or the total amount of milk delivered depending on the trip duration. To test this hypothesis on South American sea lions, we measured two attendance pattern components (foraging trip and haul-out duration) and three diving behaviour components of nursing females (dive time, bottom time and number of dives per h) at two different rookeries in Uruguay and Argentina, the composition and energy density of their milk, and the growth rate of their pups. Female foraging trip and haul-out durations depended on pup sex and weight, whereas milk energy density depended on female body mass and foraging trip durations. By contrast, the three dive variables were independent of female body mass or pup sex. Pup growth was also independent of the foraging trip and haul-out duration, with pup sex as the only significant variable. This suggests that individual differences in female foraging behaviour play a minor role in determining pup growth rates during the first three weeks after birth.
With the noose around the neck: Marine debris entangling otariid species
(Elsevier B.V., 2017-01) Franco-Trecu, Valentina; Drago, Massimiliano; Katz, Helena; Machín, Emanuel; Marín, Yamandú
Plastic debris in marine environments and its impact on wildlife species is becoming a problem of increasing concern. In pinnipeds, entanglements commonly consist of loops around the neck of nonbiodegradable materials from fishing gear or commercial packaging, known as “neck collars”. These entanglements can cause injuries, death by suffocation and starvation, and therefore they may add to the overall decrease in population. Our objective was to describe the entanglement of two species of otariids (Arctocephalus australis and Otaria flavescens) in the South West Atlantic Ocean. These two species have widely different population sizes and contrasting trends, being the O. flavescens population one order of magnitude lower in abundance with a negative population trend. A total number of 47 entangled individuals and the ingestion of a fishing sinker were recorded (A. australis: n = 26; O. flavescens: n = 22). For A. australis about 40% of the objects came from industrial fishing with which this species overlap their foraging areas, although also its lost or discarded gear can travel long distances. In O. flavescens 48% of observed injuries were very severe, which might indicate that they had been entangled for a long time. More than 60% of the objects came from artisanal and recreational fishing that operates within 5 nautical miles off the coast, which is probably related to coastal foraging habits of this species. Due to the frequent interaction between artisanal fisheries and O. flavescens, it is possible that entangled nets could be active gears. An important contribution to mitigate entanglements can be the development of education programs setting the scenario for effective communication, and exchange with involved fishermen to collect and recycle old fishing nets. Returning to natural fibers or replacement of the current materials used in fishing gear for biodegradable materials can also be a recommended mitigation measure.
Isotopic niche partitioning between two apex predators over time
(Wiley, 2017) Drago, Massimiliano; Cardona Pascual, Luis; Franco-Trecu, Valentina; Crespo, Enrique A.; Vales, Damián G.; Borella, Florencia; Zenteno Devaud, Lisette; Gonzáles, Enrique M.; Inchausti, Pablo
1. Stable isotope analyses have become an important tool in reconstructing diets, analyzing resource use patterns, elucidating trophic relations among predators and understanding the structure of food webs.2. Here, we use stable carbon and nitrogen isotope ratios in bone collagen to reconstruct and compare the isotopic niches of adult South American fur seals (Arctocephalus australis; n = 86) and sea lions (Otaria flavescens; n = 49) –two otariid species with marked morphological differences– in the Río de la Plata estuary (Argentina - Uruguay) and the adjacent Atlantic Ocean during the second half of the 20th century and the beginning of the 21st century. Samples from the middle Holocene (n = 7 fur seals and n = 5 sea lions) are also included in order to provide a reference point for characterizing resource partitioning before major anthropogenic modifications of the environment. 3. We found that the South American fur seals and South American sea lions had distinct isotopic niches during the middle Holocene. Isotopic niche segregation was similar at the beginning of the second half of the 20th century, but has diminished over time. 4. The progressive convergence of the isotopic niches of these two otariids during the second half of the 20th century and the beginning of the 21st century is most likely due to the increased reliance of South American fur seals on demersal prey. 5. This recent dietary change of South American fur seals can be explained by at least two non-mutually exclusive mechanisms: (i) the decrease in the abundance of sympatric South American sea lions as a consequence of small colony size and high pup mortality resulting from commercial sealing; and (ii) the decrease in the average size of demersal fishes due to intense fishing of the larger class sizes, which may have increased their accessibility to those eared seals with a smaller mouth gape, i.e., South American fur seals of both sexes and female South American sea lions.
Climatic niche position determines post-fire resilience in Mediterranean forests
(Wiley, 2026-02-19) Codina, Gerard; Sánchez-Pinillos, Martina; Lloret Maya, Francisco; Lecina-Diaz, Judit; Batllori Presas, Enric
Fires are a common and significant disturbance in Mediterranean forest ecosystems with a prominent role in their dynamics. The increased frequency, intensity, and extent of fires due to climate change are, however, expected to exceed forests resilience capacity. It is still unknown how resilience capacity changes across species’ biogeographical ranges in relation to pre- and post-fire environmental variability. We analyzed the resilience of Mediterranean pinewoods (Pinus halepensis and P. nigra) to fire in the Eastern Iberian Peninsula and considered the influence of pre- and post-fire climate conditions typified through the species’ climate niche. To assess forest resilience, we applied the Ecological Dynamic Regime (EDR) framework, a methodological approach to quantify the deviation of disturbed trajectories from their dynamic regimes using three indices: amplitude, recovery, and net change. Then, we evaluated how fire characteristics (severity), site attributes (exposure, rockiness), and deviations in the distance to the niche core and edge of the burned populations (centrality-marginality gradient) modulate their resilience to fire. Over 50% of the burned plots exhibited large net change from their dynamic regimes in the mid-term, denoting poor resilience regardless of the species regenerative strategy, and transitioned to shrublands or a different forest type after the fire. Recovery and net change exhibited differences between the two studied species: forests dominated by P. halepensis were overall more resilient to fire across the study range, especially in moist sites, while burned P. nigra forests showed poor recovery and large net changes after fire. For both species, forests location within the climatic niche before and after fire significantly explained post-fire resilience. In general, forests near their climatic niche core showed higher resilience compared to those close to the dry edge of the niche. Synthesis: Our study reveals that post-fire forest resilience depends not only on fire severity and fire characteristics but also on the climatic niche position of the forests. As climate warms and the frequency and intensity of fires increase, forest species will be pushed towards the dry edge of their climatic niches, likely increasing their vulnerability.

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