Coralligenous formations dominated by Eunicella cavolini (Koch, 1887) in the NE Mediterranean: biodiversity and structure

Coralligenous formations are biogenic structures typical of the underwater Mediterranean seascape. Their intricate, multi-layered species assemblages are composed of perennial, long-lived organisms, particularly vulnerable to natural or human-induced disturbances. Despite their high ecological role and conservation value, few studies have addressed the assemblages outside the NW Mediterranean. This is the first quantitative assessment of coralligenous in the N Aegean Sea (NE Mediterranean), specifically focusing at the upper bathymetric limit of assemblages that are dominated by the yellow gorgonian Eunicella cavolini. The number and percent cover of macrobenthic species were studied at depths of 18 to 35 m, using a photoquadrat method. A total of 99 benthic taxa were identified, out of which 89 perennial ones were used to investigate spatial patterns in assemblage structure, composition, and biodiversity. A mean number of 47 perennial taxa were recorded per site, with encrusting coralline algae and sponges being the dominant groups in percent cover and species number, respectively. Across the studied localities, structural complexity and community composition were overall similar, but assemblages presented distinctive differences at the level of sites highlighting the role of local abiotic and anthropogenic factors in the shaping of the coralligenous. Compared to the rest of the Mediterranean, assemblages hosted a similar number of taxa. However, the number and percent cover of erect bryozoans were generally low, while, apart from E. cavolini, other erect anthozoan species were absent. This work provides an important baseline for comparisons and monitoring at a local or Mediterranean scale level.

The understorey of gorgonian forests in mesophotic temperate reefs

1. In the Mediterranean Sea, dense populations of the gorgonian Paramuricea clavata shape marine animal forests, characterizing the seascapes of coralligenous habitats. Despite concerns for its health, with several anthropogenic threats and recent mass mortality events, mainly triggered by thermal anomalies, the understorey of its forests and the ecological processes that they promote are still little known. Here, the abundance and composition of epibenthic assemblages inside and outside P. clavata forests were investigated across the central and western Mediterranean Sea, by applying a multifactorial sampling design. 2. In spite of the large variability in the structures of epibenthic assemblages at local and regional scales, the gorgonian understoreys share some common features, such as higher abundances of calcareous builder organisms and reduced invasion by the non\u2010indigenous alga Caulerpa cylindracea, compared with the adjacent unforested rocky bottoms. Paramuricea clavata showed non\u2010linear density\u2010dependent relationships with algal turfs and non\u2010encrusting algae belonging to the genus Peyssonnelia. Moreover, by entrapping benthic mucilaginous aggregates with their branches, these gorgonians risk topical necrotic lesions, but may reduce the suffocation risks for understorey organisms. 3. Overall, P. clavata forests may enhance bioconstruction processes and increase resistance and resilience of the benthic assemblages in the Mediterranean coralligenous habitats. This species and its forests, together with their understoreys, should be considered as essential elements of the ecology of the Mediterranean Sea, and therefore worthy of specific and effective protection measures. 4. Conservation strategies should reduce the risk of mechanical damage by regulating fishing activities, anchorages, and scuba diving where gorgonian forests are present. Moreover, when evident alterations are documented, restoration actions should be implemented to recover the integrity of gorgonian forests

GuardIAS – Guarding European Waters from Invasive Alien Species

GuardIAS is a three-year Horizon Europe project starting in January 2025, uniting diverse expertise to address aquatic invasive alien species (IAS) management. This multidisciplinary initiative comprises seven interconnected work packages targeting all invasion stages (pre-border, border, post-border) to develop tools for disrupting invasions. GuardIAS will employ Artificial Intelligence and data workflows to enhance biodiversity databases with species distributions, environmental tolerances, traits, and genetic information, thereby improving the European Alien Species Information Network (EASIN) and harmonizing key datasets. The citizen science platform iNaturalist will be enriched with expert-verified images of aquatic IAS for early detection and monitoring of geographic spread. An Early Warning System focused on IAS of EU concern will be developed and integrated into EASIN. To prevent hull biofouling—a major IAS introduction pathway—GuardIAS will explore nanotechnology-based antifouling coatings. The project will also investigate recreational boat movements along European coastlines, an understudied factor in IAS secondary dispersal. An eDNA reference library and assay panel will be developed for effective IAS detection. Advanced models, such as the Nobel Prize winning Multi-Region Input-Output analysis, will assess IAS risks, including impacts on threatened species and critical habitats under current and future scenarios. Systematic conservation planning tools will prioritize IAS monitoring and management actions based on their impacts. GuardIAS will enhance data collection, monitoring, early detection, and public awareness through innovative citizen science initiatives like BioArtBlitz events—where arts serve as a communication vehicle— eDNA sampling, sound analysis projects on Zooniverse, and marina events for boaters. Stakeholder engagement will be fostered through applied games. Collaborating with environmental authorities, industry, and aquatic managers, the project will co-design and implement eradication and control efforts in marine and freshwater environments. By integrating Social Sciences and Humanities, GuardIAS will promote collaborative knowledge creation, understand public perceptions on IAS management, and facilitate exploitation of the project’s outcomes.This study was supported by the European Union’s Horizon Europe HORIZON-CL6-2024- BIODIV-01 project ‘GuardIAS - Guarding European Waters from IAS’, under grant agreement no. 101181413 and Project Establishment Support funding to Nord University from the Research Council of Norway.Peer reviewe

The application of Biologic and Synthetic bone grafts in Scoliotic Surgery. Emerging Technologies: A scoping review

This scoping review aims to explore the current landscape on biologic and synthetic bone grafts and their utilization in scoliotic surgery. It will also address the emerging technologies such as 3-D printing

Repair of duodenal trauma with the use of S.I.S. patch: an experimental study

In order to evaluate the healing of the 2nd portion of the duodenal wall with the use of Small Intestinal Submucosa (S.I.S) patch (4-ply SurgiSIS®, ES Soft Tissue Graft 2x3, COOK Biotech Inc) we studied 40 Whistar-Albino-rats in two groups of 20 animals each. In Group A, we created a small defect in the duodenal wall which was covered immediately with a SurgiSIS®patch. In group B the SurgiSIS® patch was sutured over the defect after 6-8hours, in order to develop peritonitis, mimicking the delayed management of the duodenal trauma, which is usual in everyday practice. The animals of both groups were sacrificed after 2, 6, 12 and 16 weeks and were examined both macroscopicaly and pathologicaly in order to define the degree of coverage of the defect by the patch and the development of new duodenal wall over the patch. Three animals died postoperatively due to surgical complications. In the remaining 37, as well as the three dead animals, the SurgiSIS® patch covered and sealed completely the defect of the duodenal wall. Pathologic examination showed progressive development of the layers of the duodenal wall over the patch even from the 2nd week in some of the animals of group A. In the animals of group B mucosa was developed in the 6th week, probably from the presence of inflammation due to the peritonitis. In conclusion, the SurgiSIS® patch is both efficient and safe for the management of duodenal trauma.Στο πειραματικό χειρουργείο της Α΄ Χειρουργικής Κλινικής Α.Π.Θ., στο Γ.Ν. «ΠΑΠΑΓΕΩΡΓΙΟΥ» Θεσσαλονίκης, αντιμετωπίστηκε τραυματική ρήξη δωδεκαδακτύλου σε 40 πειραματόζωα (επίμυες Whistar-albino rats) με τη χρήση εμβαλώματος από υποβλεννογόνιο χιτώνα λεπτού εντέρου χοίρου (Small Intestinal Submucosa - S.I.S) με την εμπορική ονομασία 4-ply SurgiSIS® ES Soft Tissue Graft 2x3 cm της εταιρείας Cooc Biotech Incorporated (Indiana, U.S.A). Τα πειραματόζωα χωρίστηκαν σε δύο ομάδες (Α και Β) των είκοσι ζώων η καθεμία. Στην ομάδα Α, στην πειραματικά δημιουργούμενη ρήξη του δωδεκαδακτύλου, συρράπτονταν άμεσα μόσχευμα από SIS. Προσομοιάζοντας άμεση αντιμετώπιση ρήξης δωδεκαδακτύλου. Στην ομάδα Β, η συρραφή του μοσχεύματος επί της ρήξης, γίνονταν μετά την παρέλευση 6-8 ωρών με σκοπό να δημιουργηθεί περιτονίτιδα, προσομοιάζοντας έτσι την καθυστερημένη αντιμετώπιση αυτού του είδους κάκωσης, κατάσταση συνηθισμένη στην κλινική πράξη. Τα πειραματόζωα και των δύο ομάδων θυσιάστηκαν την 2η, 6η, 12η και 16η μετεγχειρητική εβδομάδα και η περιοχή συρραφής του μοσχεύματος εξετάστηκε μακροσκοπικά και παθολογοανατομικά με σκοπό τη διαπίστωση αφενός μεν της κάλυψης της κάκωσης και αφετέρου το βαθμό ανάπλασης του δωδεκαδακτυλικού τοιχώματος επί του μοσχεύματος. Τρία πειραματόζωα (δύο από την ομάδα Α και ένα από την Β) κατέληξαν άμεσα μετεγχειρητικά από επιπλοκές σχετιζόμενες με την επέμβαση. Τόσο σ’ αυτά όσο και στα υπόλοιπα 37 που αποτέλεσαν το υλικό της μελέτης, το μόσχευμα από S.I.S κάλυψε πλήρως και στεγανά τη ρήξη του δωδεκαδακτύλου. Η παθολογοανατομική μελέτη έδειξε την προοδευτική ανάπτυξη των χιτώνων του δωδεκαδακτυλικού τοιχώματος επί του μοσχεύματος. Ήδη από τη 2η μετεγχειρητική εβδομάδα αναπτύχθηκε βλεννογόνος σε ζώο της ομάδας Α, ενώ στην ομάδα Β ο βλεννογόνος αναπτύχθηκε την 6η εβδομάδα, γεγονός που σημαίνει ότι η περιτονίτιδα καθυστερεί την ανάπλαση του τοιχώματος χωρίς όμως να επηρεάζει την επουλωτική διαδικασία. Από τα αποτελέσματα των πειραμάτων φαίνεται πως το εμβάλωμα από S.I.S θα μπορούσε να χρησιμοποιηθεί με ασφάλεια για την αντιμετώπιση των κακώσεων του δωδεκαδακτύλου στον άνθρωπο

Corrections of fish school area and mean volume backscattering strength by simulation of an omnidirectional multi-beam sonar

Abstract Fish school descriptors extracted from omnidirectional multi-beam data are biased due to beam width-related effects, and echotraces are distorted in a range-dependent manner that is a function of transducer intrinsic properties, as well as fish school characteristics. This work investigates a simulation approach that models the three-dimensional insonification of fish schools by an omnidirectional fishery sonar in order to assess the bias in measuring two key morphometric and energetic descriptors, namely the horizontal cross-sectional area of schools and their mean volume backscattering strength. Simulated fish schools of different sizes and backscattering properties were insonified at various ranges from the multi-beam transducer, outputting volume backscattering strength echograms. The simulated data were used to develop empirical models that correct the examined descriptors using only information extracted from the observed echotraces. Depending on the difference between the observed mean volume backscattering strength of a school and the echogram processing threshold, mean absolute percentage errors in measured area and volume backscatter reduced from 100.7% and 79.5% to 5.2% and 6.4%, respectively. The mean volume backscattering strength of a school is a key parameter for obtaining fish density estimates, and the results highlight the need for descriptor corrections to better interpret the multi-beam data.</jats:p

Development of an operational system for acoustic detection and tracking of large pelagic fish schools using omnidirectional multibeam sonars

The Ph.D. Thesis focuses on the acoustic study of the spatiotemporal behaviour of tuna schools associated with drifting Fish Aggregating Devices (FADs), using omnidirectional multibeam sonars. FADs play a major role in industrial tuna fisheries, however the particular fishery-characteristics strongly bias parameters concerning fishing effort and increase uncertainty regarding management strategies. It is accepted that new methodologies need to be developed for the efficient in situ assessment of aggregations around FADs, using multibeam sonars. The objective of this Thesis is to provide with quantitative in situ acoustic descriptors of tuna aggregations around drifting FADs, and to standardize certain fishery-related parameters. Acoustic recordings around FADs were acquired in the western Indian Ocean. The initial research effort focused on developing the Multibeam Sonar Tracer, an operational software for sonar raw data interface, visualization, and processing. School detection and tracking algorithms were developed and integrated to the system, allowing for automatic school isolation and extraction of quantitative descriptors. The methodology incorporates the development of a 3D school and sonar simulator, used to correct beam effect biases on school descriptors. Next to the description of the MST software and sensitivity analyses of its processing modules, the results comprise of a description of school typology and statistical analyses of school descriptors. Pelagic schools were characterized by high variability in morphology and density, and their average horizontal speed was estimated to 1.2 ms-1. A strong variability was also observed in the overall spatiotemporal distribution of schools relative to the drifting FADs, while time-series of total tracked school area and total tracked backscatter were found to be highly variable. Statistical differences were observed between day-time and night-time recordings: large schools during night-time were found to be fewer, and less dense compared to same size day-time schools. The highest biomass density was localized in a radial distance zone 400m from the drifting FADs, accounting for 80% of the total backscatter, echotrace area, and number of aggregations detected. The development and operational application of the system showed that quantitative multibeam acoustic research is feasible, and on methodological standards comparable to those used in high precision single-beam echosoundingΗ διδακτορική διατριβή εστιάζεται στην ακουστική μελέτη της συμπεριφοράς των τοννοειδών γύρω από παρασυρόμενα αντικείμενα στον ανοιχτό ωκεανό, με χρήση πολυκατευθυντικών sonar. Η υπεραλίευση τόννου με τη χρήση ειδικών πλωτήρων προσέλκυσης (FADs) είναι εντυπωσιακά ισχυρή, και οδηγεί σε κατάρρευση τα πελαγικά αποθέματα. Τα αντίστοιχα δεδομένα αλιευτικής παραγωγής είναι έντονα μεροληπτικά, καθιστώντας αδύνατη τη διαχείριση με έμμεσες μεθόδους εκτίμησης του αποθέματος. Έτσι, διατυπώνεται διεθνώς η ανάγκη προσφυγής στην υδροακουστική τεχνολογία πολυκωνικών ηχοβολιστικών, η οποία ενδείκνυται για την παρατήρηση σμηνών σε μεγάλες αποστάσεις, και την επιτόπια μελέτη των χαρακτηριστικών τους. Ωστόσο, οι επιχειρησιακές ερευνητικές απαιτήσεις ξεπερνούν τα όρια της διαθέσιμης μεθοδολογίας ανάλυσης των πολυκωνικών sonar. Αντικείμενο της διατριβής είναι η εξαγωγή ποσοτικών δεικτών περιγραφής των σμηνών τόννου γύρω από παρασυρόμενα FAD, η αντικειμενοποίηση ορισμένων παραμέτρων της αλιευτικής δραστηριότητας, αλλά και γενικότερα η από μηδενικής βάσης ανάπτυξη της σχετικής μεθοδολογίας. Οι εργασίες πεδίου έλαβαν χώρα στο δυτικό Ινδικό ωκεανό. Στα πλαίσια της διατριβής αναπτύχθηκε το λογισμικό Multibeam Sonar Tracer, που αποτελεί μία ολοκληρωμένη πλατφόρμα ανάλυσης πολυκωνικών δεδομένων, σε επιχειρησιακό επίπεδο. Αναπτύχθηκαν αλγόριθμοι αυτόματης ανίχνευσης και ιχνηλάτησης σμηνών καθώς και ένας τρισδιάστατος προσομοιωτής των συνθηκών ηχοβολισμού. Στη διατριβή παρουσιάζονται επιτόπια αποτελέσματα για την τυπολογία των σμηνών τόννου και τις κατανομές των δεικτών περιγραφής τους. Τα πελαγικά σμήνη σημείωσαν έντονη διακύμανση στα μορφολογικά και ενεργειακά χαρακτηριστικά τους και η μέση ταχύτητα κίνησής τους εκτιμήθηκε στα 1.2 ms-1. Η χωροχρονική κατανομή της πελαγικής βιομάζας έχει αντίστοιχα έντονη διαφοροποίηση, και οι χρονοσειρές της συνολικής ιχνηλατημένης ανάκλασης και εμβαδού παρουσίασαν έντονη μεταβλητότητα. Τη νύχτα, τα μεγάλα σε μέγεθος σμήνη ήταν λιγότερα σε αριθμό, και λιγότερο πυκνά σε σχέση με τα σμήνη αντίστοιχου μεγέθους την ημέρα. Η μεγαλύτερη πυκνότητα ακουστικών ιχνών παρατηρήθηκε στη ζώνη οριζόντιας απόστασης 400m περιμετρικά των FAD, περιοχή στην οποία καταγράφηκε το 80% της συνολικής ανάκλασης, εμβαδού, και πλήθους σμηνών. Η ανάπτυξη και εφαρμογή του συστήματος απέδειξε ότι η ποσοτική χρήση των πολυκατευθυντικών sonar είναι πλέον ρεαλιστική, και σε συγκρίσιμο μεθοδολογικό επίπεδο με αυτό των κατακόρυφων ηχοβολιστικώ

Medium range omnidirectional multibeam sonar observation of fish schools around drifting FADs

International audienc