Extracellular polymeric substances (EPS) are secreted by microalgae and contribute to protecting cells from damage induced by cadmium (Cd) exposure. However, the response mechanism of Chlorella sp. to Cd(II) stress as well as associated changes in the chemical properties (including functional groups and composition) of soluble EPS (SL-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (TB- EPS) in this microalga, remain unclear. This study aimed to investigate the role of EPS in enabling Chlorella sp. to resist Cd(II) stress. The results demonstrated that Cd(II) stress resulted in a significant inhibition of algal, chlorophyll a (Chl a) contents, and maximum photochemical quantum yield (Fv/Fm) of Chlorella sp., with 7 d EC30 of 6 mg/L. Nevertheless, Cd(II) exposure significantly increased both superoxide dismutase (SOD) activity and EPS content. Fourier transform infrared (FTIR) spectroscopic analysis revealed that differences existed in the functional groups involved in Cd(II) binding across algal cell density, SL-EPS, LB-EPS, and TB-EPS. The carboxyl group was identified as the most prominent functional group and were found to play a crucial role in the adsorption of Cd(II). Additionally, Tryptophan-like protein substance in EPS may be the main component binding with Cd(II) in Chlorella sp. This study indicated that Chlorella sp. resisted Cd(II) stress by increasing SOD activity and EPS content, with protein-like substance containing tryptophan proteins in EPS which could also contribute to protection against Cd stress.

Microplastic (MP) pollution is an emerging environmental concern, yet its occurrence in remote high-mountain ecosystems remains poorly understood. This study investigated MP contamination in fish from Nero Lake, an alpine lake in northwestern Italy. Between 2023 and 2024, a total of 33 specimens of Salmo trutta, Phoxinus lumaireul, and Salvelinus fontinalis were analyzed. MPs were detected in 84% of specimens in 2023 and in 93% in 2024. Filaments were the predominant particle type, while polyethylene, polypropylene, and polyethylene terephthalate were the most common polymers. In 2024, polyamide was also detected and showed the highest Polymer Hazard Index (PHI = 12.22), indicating a high hazard risk (Grade III) and elevated toxicological potential. Contamination Factor values exceeded 10 in S. trutta, and Pollution Load Index values frequently surpassed 1, both suggesting established contamination. However, the limited number of specimens, particularly for P. lumaireul and S. fontinalis, reduces statistical power and increases the risk of Type II errors. Although no significant interspecific differences in MP counts were observed, results should be interpreted with caution. Larger sample sizes are recommended but remain difficult to obtain in alpine environments. These findings highlight the vulnerability of remote lakes to both local and long-range MP pollution sources.

The order Decapoda, comprising over 17,000 extant marine species, has maintained a significant association with human societies since ancient times. This prolonged interaction initially centered on their role as a food source, subsequently expanding to encompass a broader spectrum of interests aimed at understanding their unique biological characteristics and diversity. To examine the evolution of the research focus on decapods in Spain, a bibliometric analysis was conducted. The dataset analyzed encompasses literature from various databases, culminating in a total of 913 references pertaining to decapods in Spain without temporal limitations. This analysis facilitated the creation of network maps illustrating the interconnections among primary keywords and authors as well as the progression of scientific output since the earliest recorded study in 1788. The clusters identified in the analysis delineated the principal research topics concerning Spanish decapods, highlighting the predominant areas of study, the most influential authors and institutions, and principal partner-countries establishing collaborative networks. The findings also underscore the prominence of specific journals in the development of the discipline, as well as the weight that commercially significant species have in the scientific literature. Finally, it analyzes the evolution of the research trends and emphasizes the necessity of broadening scientific enquiry to encompass other domains and lesser-known species.

Phytophthora species are known as water molds and are widespread in rivers and riparian habitats, but the distribution of these oomycetes in coastal and sea ecosystems is not well explored. The present study aims to investigate salt tolerance and potential to survive in marine environment of thirteen Phytophthora species, including P. citricola, P. plurivora, P. pseudosyringae, P. inundata, P. chlamydospora, P. gonapodyides, P. bilorbang, P. lacustris, P. pseudocryptogea, P. syringae, P. polonica, P. honggalleglyana, and P. gallica. The effect of varying concentrations of sodium chloride and the impact of sea water from the Black Sea and the Aegean Sea on mycelial growth, colony type, and formation of different morphological structures by Phytophthora species were studied. The tested isolates belong to different clades of the genus and members of clade 6 stand out with more extensive colony growth on media with elevated salt content compared to the growth on the control medium. A number of Phytophthora isolates produced morphological structures for sexual and/or asexual reproduction under salt stress conditions. The ability of the studied Phytophthora species to exist in marine environment is discussed.

Pea crabs live in association with various marine invertebrates, particularly notable for their parasitic relationship with numerous bivalves of great economic importance. During a genetic study of mussel populations on the French Atlantic coast, these crabs were found in the mantle cavity of individuals in La Tranche-sur-Mer, predominantly affecting Mytilus edulis. Given the history of mass mortality events in this area, the apparent susceptibility of M. edulis to parasitism, and the negative impact of pea crabs on host physiology, this study focused on determining the crab species found and their effects on mussels. The prevalence of infestation in this population was high (64.6%), with 61.3% of infested mussels hosting one crab and 38.7% hosting two crabs. There were no significant differences in infestation rates between male and female bivalves. Genetic analysis (16S and H3) identified the crab as Pinnotheres pisum, of which two morphotypes were observed depending on sex and stage of development. Despite the high prevalence, infested mussels showed no evidence of impaired growth or reproductive development. However, long-term studies are recommended to explore whether subtle or cumulative physiological effects of crab infestations could indirectly contribute to the mass mortality events recorded in this area.

Within biogeographic regions, local communities are structured mainly by abiotic (environmental) filtering, external resource supply, and biotic interactions. In recent years, we investigated abiotic filtering and external resource supply as drivers of the latitudinal distribution of rocky intertidal species along the Atlantic Canadian coast in Nova Scotia. Here, we evaluate biotic interactions between the main sessile species groups. Specifically, we studied abundance relationships between seaweeds and filter-feeding invertebrates and between barnacles and mussels using data collected at mid-to-high intertidal elevations at eight wave-exposed locations every summer from 2014 to 2017. We assessed such relationships for each location and year through generalized additive modeling (GAM). Of the 32 relationships evaluated for seaweeds vs. filter-feeders, 31% were significant and consistently negative, suggesting competitive interactions. For barnacles vs. mussels, 25% of the relationships were significant and mostly positive, consistent with facilitation of mussel colonization by barnacles in harsh environments. The variability explained by these models was moderate, however, between around 10% and 50%. Overall, these results suggest that interactions between the studied sessile species groups are infrequent and, when present, relatively weak in these highly stressful habitats, which supports current ecological theory on community organization.

With the purpose of understanding the trophic relationships between three herbivores that use humid high-mountain grassland and evaluating a possible interspecific competition between them and depending on the importance of the hydromorphic vegetation formations of high-mountain areas, relations were established between the attributes of these grasslands and the botanical composition of the diet of grey-breasted seedsnipe (Thinocorus orbignyianus), brown hares (Lepus europaeus), and horses (Equus ferus caballus). For two summer seasons, the botanical composition of the grassland and dry matter availability were assessed. In parallel, the botanical composition of the diets of the three herbivores was estimated through fecal microhistology. Based on the botanical composition data for both the grasslands and herbivores’ diets, their relative diversity was estimated. The Pianka index was established among the three herbivores. Hares showed greater dietary diversity (J) than horses and grey-breasted seedsnipes, factors that were negatively correlated in all three cases with the vegetation diversity patch. The same response amplitude was found when analyzing the food web. The dietary diversity for all species showed no relation to the dry matter productivity of the vegetable patches. Through analyzing the correlation of the abundance of two species of Cyperaceae in the grassland with the presence of the same in the diet of herbivores, we found a negative relationship between the abundance of Carex sp. and grey-breasted seedsnipe diet, and a positive relationship between the Eleocharis pseudoalbibracteata species abundance and frequency in the diet of hares and horses. About the group of species content of graminoids in the diet, a dietary overlap of 30% was determined in the animal species assessed; depending on that, it could identify the existence of interspecific competition between herbivores, which would be conditioned by the response of individuals to the environment. However, and according to the magnitude of the dietary overlap, a low probability of interspecific trophic competition among the studied herbivore species can be expected, which enables the use of the highland wet grassland habitat in sympatry.

Semi-natural grasslands are key biodiversity reservoirs in Mediterranean mountain ecosystems. Grazing pressure may significantly influence plant communities and soil conditions, with potential effects on ecosystem functioning. This study evaluated the impact of grazing intensity on floristic diversity, community structure, and soil physico-chemical and microbiological properties across eight grasslands in the Jbel Bouhachem massif (northern Morocco). Species richness, Shannon diversity, and floristic composition were assessed using PERMANOVA and NMDS ordination. Soil parameters and microbial groups were analyzed through laboratory measurements, with statistical comparisons based on Wilcoxon and t-tests. No significant differences were found in species richness or alpha diversity between grazing intensities, although floristic dispersion was higher under intensive grazing. Soil texture, potassium, iron, zinc, and electrical conductivity differed significantly between treatments. Among microbial groups, only yeasts and molds showed higher abundance under intensive grazing, while sulfite-reducing clostridia were exclusively detected in these plots. These results suggest that grazing intensity has a selective impact on soil properties and microbial communities, while plant diversity remains relatively stable.

This study provides the first comprehensive characterization of benthic macrofaunal communities in the Loukkos estuary, highlighting their spatial and seasonal variability and the environmental factors shaping their structure. A total of 47 species were identified across 12 site–season combinations, dominated by molluscs (47%), polychaetes (23%), and crustaceans (21%). Species richness varied considerably along the estuarine gradient, ranging from fewer than five species in the upstream sector to up to 30 species downstream. Overall, higher diversity was observed in the downstream areas and during the dry season. Macrofaunal density also exhibited substantial variability, ranging from 95 ind.m−2 to 14,852 ind.m−2, with a mean density of 2535 ± 4058 ind.m−2. Multivariate analyses identified four distinct benthic assemblages structured primarily by spatial factors (ANOSIM R = 0.86, p = 0.002), with negligible seasonal effect (R = −0.03, p = 0.6). Assemblages ranged from marine-influenced communities at the estuary mouth dominated by Cerastoderma edule, through rich and diverse seagrass-associated communities in the lower estuary dominated by Bittium reticulatum, and moderately enriched mid-estuary communities characterized by Scrobicularia plana and Hediste diversicolor, to species-poor upstream communities dominated by the tolerant species H. diversicolor. Canonical analysis showed that salinity and vegetation explain nearly 40% of the variation in benthic assemblages, highlighting the key role of Zostera seagrass beds as structuring habitats. Moreover, upstream anthropogenic pressures alter environmental conditions, reducing benthic diversity and favoring tolerant species.

Beech forests in the Italian peninsula are actively managed and they also support a high level of biodiversity. Hence, biodiversity conservation can be synergistic with timber production and carbon sequestration, enhancing the overall economic benefits of forest management. This study aimed to evaluate the effect of forest management regimes on bird communities in the Italian Peninsula during 2022 through audio recordings. We studied the structure, composition, and specialization of the breeding bird community in four managed beech stands (three even-aged beech stands aged 20, 60, and 100 years old, managed by a uniform shelterwood system; one uneven-aged stand, managed by a single-tree selection system) and one uneven-aged, unmanaged beech stand in the northern Apennines (Tuscany region, Italy). Between April and June 2022, data were collected through four 1-hour audio recording sessions per site, analyzing 5 min sequences. The unmanaged stand hosted a richer (a higher number of species, p < 0.001) and more specialized (a higher number of cavity-nesting species, p < 0.001; higher Woodland Bird Community Index (WBCI) values, p < 0.001; and eight characteristic species, including at least four highly specialized ones) bird community, compared to all the managed forests; moreover, the latter were homogeneous (similar to each other). Our study suggests that the unmanaged beech forests should be a priority option for conservation, while in terms of the managed beech forests, greater attention should be paid to defining the thresholds for snags, deadwood, and large trees to be retained to enhance their biodiversity value. Studies in additional sites, conducted over more years and including multi-taxon communities, are recommended for a deeper understanding and generalizable results.