1,721,068 research outputs found
PENNATULA RUBRA FACIES IN THE IONIAN SEA (CENTRAL MEDITERRANEAN)
Full text linkA facies of the endemic sea pen Pennatula rubra was recorded in the North-western Ionian
Sea (central Mediterranean) during 3 MEDITS trawl surveys (2012-2014). A total of 943 colonies were
sampled between 22 and 65 m in depth with a maximum density of 9492 colonies/km2 at 63 m in depth.
The main morphological differences from the congeneric Pennatula phosphorea are also reported.
Key-words
SECRETS IN THE SANDS: MICROMOLLUSCS OF ISOLE TREMITI MPA
No full textThe analysis of the sands sampled in the Isole Tremiti MPA revealed the remarkable presence of micromolluscs shells (22 Gastropoda and 2 Bivalvia), mainly of species living within the Posidonia oceanica meadows or as ectoparasites of benthic invertebrates. Nine of the 24 species are not included in the main previous checklists, suggesting a wide lack of knowledge about micromolluscs
A mesophotic black coral forest in the Adriatic Sea
Full text linkA forest of the black coral Antipathella subpinnata was found from 52 to 80 m depth in three different sites at Tremiti Islands Marine Protected Area (MPA; Mediterranean Sea), with two of them hosting a monospecific forest on horizontal and vertical substrates. Colonies of A. subpinnata showed a mean density between 0.22 ± 0.03 and 2.40 ± 0.26 colonies m-2 (maximum local values of 2.4-7.2 colonies m-2). The link between the local distribution of A. subpinnata and the main oceanographic features confirmed the fundamental role of the currents in shaping the distribution of the species in presence of hard substrata. This black coral forest represents the only one known thus far in the Adriatic Sea, but it could be linked with other unseen forests all over the Mediterranean Sea. The associated megafauna highlights the importance of these forests as habitat for species of both conservation and commercial importance but, at the same time, makes such habitat a target for fishing practices, as many lost fishing gears were found within the coral forest. The enlargement of the MPA borders and the enforcement of controls in the area of the A. subpinnata forest is urgently needed for the proper conservation of this protected species
Corallith bed of the endangered coral Cladocora caespitosa in the South Adriatic Sea
No full textThe colonial coral Cladocora caespitosa is a Mediterranean-endemic scleractinian structuring ecosystems of great conservation and ecological importance. Their nomenclature is here revised distinguishing between three different C. caespitosa formations: beds, grounds and reefs. Here we describe an extensive C. caespitosa bed at Tremiti Islands (Italy, Adriatic Sea), where thousands of colonies develop as free-living coral nodules (coralliths) on a soft, detritic bottom. Colonies were seldom present shallower than 15 m depth as well as on rocky bottoms, while their density increased with depth up to 700 colonies 100 m− 2 at 22 m. Their bathymetric occurrence was primarily influenced by seawater temperatures, particularly during summer, when a marked thermocline act as protection against high temperatures. The conservation status of the C. caespitosa bed was overall good, with low epibiosis/necrosis, and negligible bleaching. Demographic traits and size-structure of both colonies and polyps (through corallites) are reported. These rare coral formations might be affected by anthropogenic threats at both local and global scale, thus appropriate conservation measures are needed to avoid significant impacts in the future
Eastward spreading of the invasive Rugulopteryx okamurae (Heterokontophyta, Dictyotales) in the Mediterranean: first record in the Adriatic Sea
Full text linkThe brown seaweed Rugulopteryx okamurae is currently included in the list of invasive alien species of European Union concern due to its rapid expansion that is causing both ecological and economic impacts. In this study, we report the first record of R. okamurae in the Southern Adriatic Sea, off the coast of Bari, Italy, currently representing the easternmost limit of its distribution in the Mediterranean Sea. Morphological observations combined with rbcL and psbA sequence analyses confirmed the taxonomic identification. Field surveys carried out between April 2023 and January 2024 highlighted the conspicuous occurrence of R. okamurae over a total surface of approximately 6.5 ha. Two main human-mediated pathways occurring near the sites of the first observation of the alien species may have been responsible for its introduction: the trade in living organisms for human consumption and maritime transport related to the proximity of the port of Bari to the invaded area. Future studies will aim to identify and implement practical, cost-effective management strategies to mitigate this alarming bioinvasion
First record of Protoptilum carpenteri (Cnidaria, Octocorallia, Pennatulacea) in the Mediterranean Sea
Full text linkThis paper reports the first finding of the sea pen Protoptilum carpenteri Kölliker, 1872 in theMediterranean Sea. A total of three
colonies were collected in 2010 with an epibenthic sledge, and one colony in 2013 with a bottom-trawl net, in the Santa Maria
di Leuca (SML) coral province in the Ionian Sea. The main anatomical features and taxonomic characteristics are reported
and discussed in order to update the knowledge of this species. A description of morphologies and dimensions of the sclerites,
taken from different parts of the colony, is reported. A comparison with Atlantic records is given and discussed
The new face of the northernmost coral reefs of the Maldives revisited after 13 years
No full textCoral reef ecosystems in Ihavandhippolhu Atoll, the northernmost atoll of the Maldives, have undergone significant changes following the 1998, 2010, and 2016 bleaching events. This study evaluates the recovery after 13 years following repeated bleaching events and the shift in coral reef composition in this remote and scantly explored region of the Indian Ocean. Data collected in January 2024 from ten strategic sites within the atoll reveal substantial shifts in benthic composition compared to earlier surveys from 2011. We observed a significant increase in overall hard coral cover, with resilient taxa—such as massive and encrusting corals—becoming dominant after bleaching events. In contrast, more sensitive genera like branching and tabular Acropora have declined sharply, indicating a shift in the benthic community composition toward more resistant coral taxa. The substantial recovery of hard coral cover over time suggests the resilience of the coral ecosystem in this remote atoll, although the recovery process is still ongoing, as shown by the incomplete restoration of original diversity and colony growth forms. A standardized and periodic monitoring plan in Ihavandhippolhu Atoll will be needed to track the ongoing changes in reef community composition under conditions of minimal human influence
Preliminary assessment of Cladocora caespitosa population at Tremiti Islands Marine Protected Area (Southern Adriatic Sea)
No full textThe scleractinian Cladocora caespitosa is a Mediterranean-endemic bioconstructor of the infralittoral zone. This study reports the occurrence of C. caespitosa living in the lower layer of the infralittoral zone (from 15 to 21 m depth), on detritic bottom consisting of gravels and rhodoliths, at Tremiti Islands Marine Protected Area (Southern Adriatic Sea). The density and coverage measured are one of the highest reported thus far. Our results are particularly relevant because most of the studies reported the scarce presence of this species on lower-infralittoral soft substrates. Three photo-transects were carried out at 15, 18 and 21 m depth, and preliminary differences found between the three transects can be explained by the depth gradient, with probable high influence of waves and currents. Colonies were in good conservation status, being mostly healthy and not affected by bleaching or mechanical damage. Further studies will be focused on finding new populations of this coral at Tremiti archipelago, as well as on searching for the presence of any relation between distribution and bio-ecological traits with abiotic factors
Flowering of Posidonia oceanica in the Italian Adriatic Sea following the 2024 marine heatwave
No full textMass flowering events of the seagrass Posidonia oceanica are rare reproductive phenomena that may reflect environmental stress responses and are pivotal for its survival over the coming decades within the global changes scenario. In December 2024, a widespread and synchronous flowering was observed across four meadows along the Southern Adriatic coast of Italy (Apulia Region), following a marine heatwave. Four meadows were surveyed by SCUBA diving, with shoot density (bundles m−2) and inflorescence counts to assess flowering intensity (FI, %) investigated at 10 stations per meadow. Sea Surface Temperatures (SSTs) and sunspot data from 1990 to 2024 were also analysed to explore the role of global warming in triggering the flowering event, as observed for many meadows in the past. All meadows exhibited inflorescences in 100 % of the sampling stations, with an overall mean FI of 33.57 ± 11.71 %, and peaks up to 66 %. Shoot density and FI were positively correlated: the denser the meadow, the higher the FI. SST data for the Southern Adriatic Sea revealed that 2024 was the warmest year in the last three decades, with record-breaking SSTs and a record 72 days exceeding 26 °C. This supports the hypothesis that temperature anomalies and prolonged thermal stress may be key triggers of sexual reproduction in P. oceanica. This event, one of the most intense ever recorded, poses further questions about the role of flowering events in the resilience and regeneration of P. oceanica meadows, as well as implications for the conservation of this fundamental coastal ecosystem
ROV vs trawling approaches in the study of benthic communities: The case of Pennatula rubra (Cnidaria: Pennatulacea)
No full textMegabenthic soft bottom communities of trawlable grounds have been studied since the first few decades of the last century, thanks to trawl fishing technologies. Despite providing an extensive amount of presence data, trawling cannot be considered reliable from a quantitative point of view, frequently giving only weak information about sessile species density, large and small-scale distribution and main habitat features. The recent development of visual technologies on remotely operated vehicles (ROVs) can give a more accurate approach for the study of mega-epibenthic communities. The present study reports the application of both ROV imaging and trawling approaches for the study of a large aggregation (i.e. field) of the red sea pen Pennatula rubra in the Ionian Sea. Density, biomass and population structure were studied in the same population of P. rubra. The density assessed by ROV was significantly higher than that estimated with a three-year series of trawling surveys. Trawling gear efficiency in the removal of P. rubra was low overall. Incidental mortality can be very high due to damage to those specimens that encounter the trawl net but are not directly captured. However, sampling of several colonies by trawling was necessary to establish biometric correlations to estimates of size and biomass from ROV imaging. Trawling catch abundance/biomass data could be useful to identify areas of higher concentration of sea pens, while ROV imaging can be used to monitor these fields in a non-destructive manner that would be consistent with protection measures
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