Browsing by Issue Date, starting with "2025-08-06"
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- Microbiome matters: how transplantation methods and donor origins shape the successful restoration of the seagrass Posidonia oceanicaPublication . Boulenger, Arnaud; Aires, Tania; Engelen, Aschwin; Muyzer, Gerard; Marengo, Michel; Gobert, SylvieBackground Posidonia oceanica forms extensive seagrass meadows in the Mediterranean Sea, providing key ecosystem services. However, these meadows decline due to anthropogenic pressures like anchoring and coastal development. Transplantation-based restoration has been explored for decades, yet the role of the plant-associated microbiome in restoration success remains largely unknown. Results 16 S rRNA gene amplicon sequencing was used to investigate how different transplantation methods and donor origins influence the bacterial communities of P. oceanica cuttings two years post-transplantation. We tested three transplantation methods, iron staples, coconut fiber mats, and BESE elements, and compared them with control meadows and donor populations from two different origins: naturally uprooted storm-fragments and intermatte cuttings manually harvested from established meadows. Our results show that transplantation methods strongly shape bacterial communities in seagrass roots. Iron staples promoted microbial assemblages most similar to natural meadows, likely due to direct sediment contact enhancing recruitment of key functional bacterial orders such as Chromatiales and Desulfobacterales. In contrast, BESE elements and coconut fiber mats displayed dissimilar bacterial communities compared to control meadows, likely due to material composition and physical separation between the cuttings and the sediment. Donor origin had only subtle effects on bacterial communities’ structure, although intermatte cuttings showed higher abundances of Candidatus Thiodiazotropha, a genus thought to be involved sulfur oxidation and nitrogen fixation. Conclusion Our results demonstrate that transplantation methods strongly influence root-associated bacterial communities. Limited sediment contact in elevated substrates delayed the establishment of key functional bacteria, highlighting the importance of direct interaction with the sediment microbial pool. These results imply that restoration strategies should prioritize methods enhancing sediment–root interactions to support microbial recovery. Incorporating microbiome considerations, such as optimized substrates or microbial inoculation, could improve the resilience and long-term success of P. oceanica restoration.
- Coral garden conservation and restoration: how host taxon and ex-situ maintenance affect the microbiome of soft and hard coralsPublication . Rola, Marcellina; Coelho, Márcio A. G.; Pruckner, Christian; Quiroga-Pérez, Manuela; Stock, Willem; Baylina, Núria; Engelen, Aschwin; Wägele, Heike; Serrao, Ester A.; Frade, Pedro R.Temperate coral gardens are dense coral formations, which support rich marine species diversity, enabling benthic-pelagic coupling. Over the past decades, coral gardens have been increasingly threatened by bottom fishing, oil and gas exploitation, and climate change. Microbiome research bears great potential for assisted resilience in targeted conservation and restoration approaches. Yet, fundamental parameters of the coral garden microbiome remain poorly understood. Here, we provide a first broad record of bacterial communities associated with NE Atlantic coral garden corals and their community changes as response to human maintenance in conservation research. Octocorals (10 species), scleractinians (2 species) and one black coral species, were opportunistically collected from fisheries bycatch at 60-480 m depth around Cape St. Vincent (SW Portugal). Metabarcoding of the 16S-rRNA gene using third-generation sequencing revealed a high microbial host-specificity in the wild-collected coral species analyzed, and supported the importance of bacterial families Endozoicomonadaceae (mean relative abundance +/- SE; 28.3 +/- 10.5%), Spirochaetaceae (8.2 +/- 5.8%) and Spongiibacteraceae (4.6 +/- 1.8%). Endozoicomonadaceae were particularly dominant in the octocoral order Malacalcyonacea (67.7 +/- 14.5%). The low microbial alpha diversity and limited interspecies differences among the Malacalcyonacea species suggest a conserved microbiome within this group, as compared to orders Scleralcyonacea, Antipatharia, and Scleractinia. Microbial responses to ex-situ maintenance of two branching octocoral species, Eunicella verrucosa and Paramuricea cf. grayi (Order Malacalcyonacea), were investigated (1) over 45 days under standardized aquaria conditions in the research station (Ramalhete Marine Station, CCMAR) and (2) over long-term captivity in two public aquaria, Ocean & aacute;rio de Lisboa and Zoomarine. Eunicella verrucosa displayed a stronger microbial community shift to short-term captivity (45 days), in contrast to greater microbiome stability in P. cf. grayi. However, long-term captivity in public aquaria led to microbiome shifts in both species. The strong host specificity of microbial diversity and its response to maintenance indicate that conservation and restoration of coral gardens require taxon-specific strategies.
- Sustainable use of volcanic ash in mortars as a replacement for cement or sand: shrinkage and physical and mechanical propertiesPublication . Gil-Martín, Luisa María; Oliveira, Miguel José; Fernández-Ruiz, Manuel Alejandro; Branco, Fernando G.; Hernández-Montes, EnriqueThe eruption of the Cumbre Vieja volcano on 19 September 2021 resulted in the deposition of over 20 million cubic meters of tephra, posing significant environmental and logistical challenges in the affected areas. This study aimed to explore the valorization of volcanic ash (VA) by evaluating its potential use in producing sustainable mortar by incorporating it as a replacement for cement or sand. Various experimental mixtures were prepared with different proportions of VA which substituted either cement or sand, and these mixes were characterized through a mechanical and microstructural campaign. Additionally, shrinkage was evaluated for the mixtures which showed good mechanical results. The results suggest that partially replacing cement with up to 15% ground VA as well as substituting sand with up to 25% VA are promising strategies for the production of sustainable mortar mixes. This research contributes to the understanding of the influence of VA in cementitious matrices and offers a novel approach for integrating locally available geomaterials into infrastructure design in volcanic active regions.