MAPPING COMMUNITY INTEREST HABITATS IN THE COLUMBRETES ARCHIPELAGO, AN EXTRAORDINARY HOT SPOT OF BIODIVERSITY

The Columbretes Archipelago and their submerged surroundings are part of an unusual, Pleistocene volcanic field located in the Western Mediterranean designated as a Site of Community Importance (SCI) of the Natura 2000 Network. In the present study, 4 benthic habitats of community interest (1110, 1170, 1180 and 8330) have been identified by analyzing several sources of information. Generalized additive models (GAMs) have been used to model the potential distribution of reefs (1170) and maërl beds (1110). Our results highlight the diversity and extent of these habitats and allow comparisons to other marine SCIs of Spain. This can be attributed to the variability of the environment of this site. The Columbretes Islands combine a relatively shallow environment with volcanic structures, hydrothermalism with active degassing, current-driven sedimentary lobes and the influence of inland flows. Understanding high biodiversity spots is crucial as they offer natural laboratories to describe how ecosystems respond to the effects of global change. The knowledge obtained will be of paramount importance for the conservation of species and habitats. Furthermore, it will establish a baseline for future monitoring and assist in the development of effective management plans

Monitoring the complex benthic habitat on semi-dark underwater marine caves using photogrammetry-based 3D reconstructions

Marine caves are dark environments considered a priority habitat for conservation included in the EU Habitats Directive (H8330). They harbor fragile benthic communities and represent a major reservoir of marine biodiversity. However, there is a lack of knowledge of these habitats due to the difficulties of creating detailed benthic maps and characterizing the biodiversity, structure, and dynamics of their communities. The uniqueness of marine caves fosters their popularity among recreational divers, who can cause disturbances through abrasion of the biota, resuspension of sediment, and accumulation of exhaled air bubbles in the caves' ceilings. This study aims to build a monitoring framework to characterize the structure and temporal dynamics of this complex habitat using Structurefrom- Motion (SfM) photogrammetry. SfM is a novel, non-invasive technique that allows a major advancement in the monitoring of changes in the cave’s community assemblages. This method relies on images acquired by 4K video footage to build fine-scaled 3D digital models of the substrate using overlapping imagery. For this study, we combined SfM photogrammetry and photo quadrats extracted from the video recordings. We evaluate the effectiveness of this methodology in a marine cave highly frequented by divers, located in Illa de l’Aire (Balearic Islands, Spain), and carried out two surveys before and after the diving season (2019-2021). As a result, we found a loss of 25 colonies of bryozoans with fragile skeletons, like Schizoretepora sp., and 8 individual sponges with globose morphotypes. Our results indicate that this methodology enables accurate and efficient monitoring of benthic communities in underwater caves that allow us to better understand their dynamics and, therefore, to develop the need management measures

Urinary proteomic signature of mineralocorticoid receptor antagonism by spironolactone: evidence from the HOMAGE trial

Objective: Heart failure (HF) is characterised by collagen deposition. Urinary proteomic profiling (UPP) followed by peptide sequencing identifies parental proteins, for over 70% derived from collagens. This study aimed to refine understanding of the antifibrotic action of spironolactone. Methods: In this substudy (n=290) to the Heart ‘Omics’ in Ageing Study trial, patients were randomised to usual therapy combined or not with spironolactone 25–50 mg/day and followed for 9 months. The analysis included 1498 sequenced urinary peptides detectable in ≥30% of patients and carboxyterminal propeptide of procollagen I (PICP) and PICP/carboxyterminal telopeptide of collagen I (CITP) as serum biomarkers of COL1A1 synthesis. After rank normalisation of biomarker distributions, between-group differences in their changes were assessed by multivariable-adjusted mixed model analysis of variance. Correlations between the changes in urinary peptides and in serum PICP and PICP/CITP were compared between groups using Fisher’s Z transform. Results: Multivariable-adjusted between-group differences in the urinary peptides with error 1 rate correction were limited to 27 collagen fragments, of which 16 were upregulated (7 COL1A1 fragments) on spironolactone and 11 downregulated (4 COL1A1 fragments). Over 9 months of follow-up, spironolactone decreased serum PICP from 81 (IQR 66–95) to 75 (61–90) µg/L and PICP/CITP from 22 (17–28) to 18 (13–26), whereas no changes occurred in the control group, resulting in a difference (spironolactone minus control) expressed in standardised units of −0.321 (95% CI 0.0007). Spironolactone did not affect the correlations between changes in urinary COL1A1 fragments and in PICP or the PICP/CITP ratio. Conclusions: Spironolactone decreased serum markers of collagen synthesis and predominantly downregulated urinary collagen-derived peptides, but upregulated others. The interpretation of these opposite UPP trends might be due to shrinking the body-wide pool of collagens, explaining downregulation, while some degree of collagen synthesis must be maintained to sustain vital organ functions, explaining upregulation. Combining urinary and serum fibrosis markers opens new avenues for the understanding of the action of antifibrotic drugs. Trial registration number: NCT02556450