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Endemic Mediterranean seagrass Posidonia oceanica is highly endangered today as it lives in a narrow infralittoral zone intensely exposed to human impact. P. oceanica beds are especially endangered in the Adriatic Sea as the central and northern Adriatic could be considered as a naturally suboptimal area for P. oceanica growth. In this research, we used some standard descriptors of Posidonia meadows at different locations and depths and determined the biochemical parameters (phenolic compounds, photosynthetic pigments, and enzyme activities) in its leaves in order to find possible correlations among the measured parameters and environmental conditions. Photosynthetic pigments were shown to be sensitive biomarkers in the assessment of P. oceanica response to different light conditions, but more research is needed to elucidate the impact of other environmental factors. Overall, the results of this research show that the studied parameters are good bioindicators of a meadow’s environmental state, but it is necessary to analyze a number of diverse indicators together to properly characterize the state of a particular P. oceanica meadow. This approach would be very useful in the determination of P. oceanica conservation status, which is the first step towards improving monitoring protocols and implementing appropriate conservation measures.

The Gray’s sea fan, Paramuricea grayi (Johnson, 1861), typically inhabits deep littoral and circalittoral habitats of the eastern temperate and tropical Atlantic Ocean. Along the Iberian Peninsula, where P. grayi is a dominant constituent of circalittoral coral gardens, two segregating lineages (yellow and purple morphotypes) were recently identified using single-copy nuclear orthologues. The mitochondrial genomes of 9 P. grayi individuals covering both color morphotypes were assembled from RNA-seq data, using samples collected at three sites in southern (Sagres and Tavira) and western (Cape Espichel) Portugal. The complete circular mitogenome is 18,668 bp in length, has an A + T-rich base composition (62.5%) and contains the 17 genes typically found in Octocorallia: 14 protein-coding genes (atp6, atp8, cob, cox1-3, mt-mutS, nad1-6, and nad4L), the small and large subunit rRNAs (rns and rnl), and one transfer RNA (trnM). The mitogenomes were nearly identical for all specimens, though we identified a noteworthy polymorphism (two SNPs 9 bp apart) in the mt-mutS of one purple individual that is shared with the sister species P. clavata. The mitogenomes of the two species have a pairwise sequence identity of 99.0%, with nad6 and mt-mutS having the highest rates of non-synonymous substitutions.

In the last few years, the endemic Mediterranean bivalve Pinna nobilis has been exposed to dramatic mortality in its entire area, which could lead to the extinction of the species. Throughout the Mediterranean, a lot of effort is being put into finding ways of preserving it. One of the methods used to monitor recruitment and juveniles’ survival is the installation of collectors for bivalve larvae. We installed collectors at two locations: in Brijuni National Park (North Adriatic) and Luka Cove (central Adriatic). Our aim was to compare the fouling community on the collectors in two consecutive years (2019 and 2020), especially because the installation of collectors in 2020 coincided with mass mortality events of P. nobilis in the area. The number and size of juvenile P. nobilis and the qualitative and quantitative composition of the fouling communities were determined. The results show a reduction in the number and size of juvenile P. nobilis and an explosion of the invasive bivalve Anadara transversa population on collectors in the second year. In Luka Cove, another invasive species—the ascidian Styela plicata—also seriously affected other organisms on the collectors to the point of preventing analysis of the fouling community.

A devastating mass mortality event (MME) very likely caused by the protozoan Haplosporidium pinnae first detected in 2016 in the Western Mediterranean Sea, is pushing the endemic bivalve Pinna nobilis to near extinction. Populations recovery, if possible, will rely on larval dispersal from unaffected sites and potential recolonization through recruitment of resistant juveniles. To assess the impact of the MME on the species’ larval recruitment, an unprecedented network of larval collector stations was implemented over several thousands of kilometers along the Western Mediterranean coasts during the 3 years after the onset of the MME. The findings of this network showed a generalized disruption in recruitment with dramatic consequences for the recovery of the species. However, there were exceptions to this pattern and recruits were recorded in a few sites where the resident population had been decimated. This hints to the importance of unaffected populations as larval exporting sources and the role of oceanographic currents in larval transport in the area, representing a beacon of hope in the current extremely worrying scenario for this emblematic species.

Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV) ubiquitously expressed (FAU) gene is down-regulated in human prostate, breast and ovarian cancers. Moreover, its dysregulation is associated with poor prognosis in breast cancer. Sponges (Porifera) are animals without tissues which branched off first from the common ancestor of all metazoans. A large majority of genes implicated in human cancers have their homologues in the sponge genome. Our study suggests that FAU gene from the sponge Suberites domuncula reflects characteristics of the FAU gene from the metazoan ancestor, which have changed only slightly during the course of animal evolution. We found pro-apoptotic activity of sponge FAU protein. The same as its human homologue, sponge FAU increases apoptosis in human HEK293T cells. This indicates that the biological functions of FAU, usually associated with “higher” metazoans, particularly in cancer etiology, possess a biochemical background established early in metazoan evolution. The ancestor of all animals possibly possessed FAU protein with the structure and function similar to evolutionarily more recent versions of the protein, even before the appearance of true tissues and the origin of tumors and metastasis. It provides an opportunity to use pre-bilaterian animals as a simpler model for studying complex interactions in human cancerogenesis.

Fishing activities and other anthropogenic influences have direct and indirect effects on fish community structure. One expectation may be that with increasing fishing pressure and decreasing size selectivity of fisheries all predator populations decline and consequently fish assemblages change. Comparisons of MPAs with unprotected areas are considered valid natural experiments to test hypotheses on how predation structures communities. Here we report on the use of a lure-assisted visual census in the Central Croatian Adriatic to assess and compare fish assemblages in MPA sites (Kornati NP) with adjacent unprotected sites. We detected a significant protection effect on mesopredator abundance and overall fish diversity/richness and that protection status explained a significant portion of the fish assemblage variability, all independent of additional predictor variables, like habitat and depth. As we continue to expand the spatiotemporal scale and magnitude of the approach, we hope that it will eventually provide us with a long-term data series needed for testing many hypotheses in coastal ecology, including the effects of MPAs, coastal development, fishing and global climate change on the species interactions, abundance, diversity and assembly of animal species across multiple spatial scales.

We derive statistical properties of standard methods for monitoring of habitat cover worldwide, and criticize them in the context of mandated seagrass monitoring programs, as exemplified by Posidonia oceanica in the Mediterranean Sea. We report the novel result that cartographic methods with non-trivial classification errors are generally incapable of reliably detecting habitat cover losses less than about 30 to 50%, and the field labor required to increase their precision can be orders of magnitude higher than that required to estimate habitat loss directly in a field campaign. We derive a universal utility threshold of classification error in habitat maps that represents the minimum habitat map accuracy above which direct methods are superior. Widespread government reliance on blind-sentinel methods for monitoring seafloor can obscure the gradual and currently ongoing losses of benthic resources until the time has long passed for meaningful management intervention. We find two classes of methods with very high statistical power for detecting small habitat cover losses: 1) fixed-plot direct methods, which are over 100 times as efficient as direct random-plot methods in a variable habitat mosaic; and 2) remote methods with very low classification error such as geospatial underwater videography, which is an emerging, low-cost, non-destructive method for documenting small changes at millimeter visual resolution. General adoption of these methods and their further development will require a fundamental cultural change in conservation and management bodies towards the recognition and promotion of requirements of minimal statistical power and precision in the development of international goals for monitoring these valuable resources and the ecological services they provide.