Biology subjects

Sabatino, R.

Publications and source records attributed to Sabatino, R..

3 recordsLinked to original sources

bioRxiv2026

Meiofaunal communities flourish in Antarctic marine sediments despite the harsh environmental conditions

While Antarctic terrestrial ecosystems support low metazoan diversity, the surrounding marine macrobenthos is rich. However, marine meiofauna remains historically neglected, leaving its diversity patterns unclear. In this study, we used 18S rRNA gene metabarcoding alongside an enhanced taxonomic annotation pipeline to characterize marine meiofauna diversity in the Ross Sea, comparing it to global datasets. We evaluated how depth, habitat type, and mesh size influence community structures to test if habitat heterogeneity drives diversity despite the harsh Southern Ocean conditions. Our results revealed exceptionally high diversity, with metazoans richness comparable to or higher than temperate regions. Although environmental variables had limited effects on taxonomic richness, they significantly shaped community composition, with habitat type explaining the highest proportion of variance. Interestingly, we detected several ASVs 100% identical to North Sea and North Atlantic sequences, likely reflecting the limited taxonomic resolution of the 18S marker rather than global dispersal (the "meiofaunal paradox"). Overall, these findings demonstrate that Antarctic marine sediments host rich meiofaunal communities where ecological processes operate similarly to other global regions, contrasting sharply with depauperate continental Antarctic ecosystems.

ecology↗

bioRxiv2025

Multilayered human activities shape the microbial communities of groundwater-dependent ecosystems in an arid oceanic island

Island coastal aquifers, though physically small compared to continental groundwater systems, are of huge ecological and societal importance, sustaining functions that connect to locally crucial provision, maintenance and culture ecosystem services. Those functions are largely dependent on the presence of highly adapted biological communities, for which, their microbial communities remain understudied. Our goal is to describe the bacterial communities across the groundwater-dependent ecosystems on Lanzarote, spanning a gradient of anthropogenic pollution using 16SrRNA amplicon sequencing. We sampled coastal caves and pools, wells and water galleries, springs, saltworks and marine bays affected by submarine groundwater discharge. Ecological analyses highlight that richness and composition of bacterial communities strongly depend on the type of habitats. Pathogens and human-derived species were ubiquitous in our samples, but, strikingly, caves and wells were strongly enriched with them compared to other habitats. We propose that our results highlight the susceptibility of groundwater environments to pollution and indicate that aquifers act as reservoirs of biological contamination in addition to natural diversity--regardless of their salinity. Since this enrichment might compromise some of the functions and services that groundwater-dependent ecosystems provide in oceanic islands, we call for integrative conservation strategies that include hydrological and biological perspectives into the decision making.

microbiology↗

bioRxiv2025

Constructed wetlands for aquaculture wastewater treatment: insights on the structural and functional shifts of the aquatic microbial community

Aquaculture practices generate nutrient-rich effluents with associated microbiological hazards, such as pathogens and antimicrobial resistance genes (ARGs). Despite their growing popularity as nature-based solutions, little is known about how constructed wetlands (CWs) affect the dynamics of microbial communities at the field scale. By combining flow cytometry, 16S rRNA gene sequencing, shotgun metagenomics, and metabolic potential assays, we investigated the structural and functional responses of the aquatic microbial community following the recurrent exposure to CW-treated effluents from an intensive marine fish farm (Orbetello lagoon, Italy). While the CW promoted abundant, metabolically active, and functionally redundant microbial communities, the phylogenetic composition diverged primarily between water and sediments. Microbial profiles in CW outlet waters converged towards those of the lagoon baselines, suggesting gradual ecological recovery. The CW attenuated the occurrence of potential pathogens (e.g., Francisella spp., Campylobacter spp.) and limited ARG dissemination, though sediments remained reservoirs of microbial and genetic signatures. Functional profiles, dominated by chemoheterotrophy, denitrification, and sulfur respiration, remained stable across environments, reflecting microbial resilience. Our results highlight CWs as effective, field-proven solutions to mitigate aquaculture wastewater impacts while preserving core ecosystem services.

ecology↗