[First record of the runt eggs of the Imperial Cormorant Phalacrocorax atriceps and the Rock Shag P. magellanicus in the San Jorge Gulf, Argentina]

[The present study describes for the first time the abnormally small (runt) eggs of the Imperial Cormorant (IC) and Rock Shag (RS) observed during the breeding seasons of 1990/91, 1992/93, 1993/1994, 1994/95 and 1996/97 on the Isabel Island (45°07'S, 66°30'W) and the Galiano Island (45°06'S, 66°25'W), located in the northern San Jorge Gulf, Argentina. The frequency of occurrence of IC runt eggs was 0.2% (n = 995) and their average volume was significantly lower than normal eggs (t = 17.4, P< 0.0001, n = 824). The runt eggs were more spherical than those of normal size (Shape Index: 70.6 vs 64.5 for CI and 74.9 vs 63.9 for RS). The volume of the RS runt egg was 21.1 cm3. The cutoff between normal and runt eggs is between 30 and 35 cm3 for the IC and between 24 and 30 cm3 for the RS. The volume of the runt egg was 42.1% and 53.4% the average volume of the two remaining eggs of the clutch for CI and RS, respectively. None of the consistently observed IC runt eggs hatched and it seems that none of the eggs showing a volume lower than the proposed cutoff is destined to hatch]. [Article in Italian

Hydrodynamic forcing and sand permeability influence the distribution of anthropogenic microparticles in beach sediment

The distribution of anthropogenic microparticles (Mps), such as plastic and natural fibres used in textiles, in beach sediments was studied in a human-influenced pocket beach in Liguria (NW Mediterranean Sea). Information on environmental parameters such as rainfall, hydrodynamic characteristics and sediment texture was collected at the same time as the sediment samples. The Mps (416 +- 202 Mps kg-1 on average) were mainly fibres (57\u2013100%), while fragments and spheres showed irregular abundances linked to the draining action of waves on the beach. Uni- and multivariate statistical analyses highlighted that the different spatial and seasonal distribution of fibres primarily depended on the action of the waves that force seawater into the sand, rather than on sedimentation following depositional processes. Wave height and direction had a role in fibre distribution in the sand, as well as sediment permeability and sorting. The occurrence of short-term and spatially-localised hydrodynamic events such as rip currents were observed to influence the abundance of fibres, overlapping the seasonal sequences of beach accretion and erosion that is typical of the area and increasing fibre abundance by transporting those accumulated in the sediments of the submerged beach during winter

Macrofaunal assemblages in canyon and adjacent slope of the NW and Central Mediterranean systems

Macrofaunal assemblages were studied along bathymetric transects in six canyons and four adjacent open slopes of the Mediterranean Sea. The different areas investigated were located approximately along a longitudinal gradient at similar latitudes. Three regions were investigated: the Catalan (from 334 to 1887 m depth), the Ligurian (from 222 to 2005 m depth) and the South Adriatic margins (from 196 to 908 m depth). The analysis of the meso-scale distribution of assemblage structure and biomass showed significant differences among regions, which resulted in high values of \u3b4-diversity. Clear differences in trophic composition were also observed, and a decreasing pattern in the individual body size of macrofaunal organisms moving Eastward. These patterns were apparently linked to changes in food supply, whereas macrofaunal abundance and number of taxa showed a decrease pattern with increasing water depth. When the assemblage structure was compared between canyons and adjacent open slope, a very high \u3b2-diversity was observed, indicating that the bottom topography exerted a strong effect on the assemblage characteristics

The allochthonous material input in the trophodynamic system of the shelf sediments of the Gulf of Tigullio (Ligurian Sea, NW Mediterranean)

The organic allochthonous material input in the benthic system of a NW Mediterranean shelf area was studied using a three-pronged approach, focusing firstly on the evaluation of the sedimentary stable isotope ratios and organic matter (OM) composition, then on the OM recycling processes performed by the microbial organisms, and finally on the potential trophic relationships between the macrobenthic organisms. The highest allochthonous signal, indicating continental input, was observed within the 50-m isobath, while at the 80-m isobath the marine signal was higher, pointing to a rather low continental influence approximately 5&nbsp;km from the shore. Heavier rainfall, often generating abrupt allochthonous inputs by river outfalls, led to a wider spread of fine sediment particles. Carbohydrates were the compounds that best represented the continental input and these compounds were associated with potential recycling activities by microbiota, pointing to the entry of these C-containing allochthonous materials into the microbial food web. The macrofaunal deposit-feeders used sedimentary OM characterised by a continental signature as a food source, although the isotopic ratios of the organisms also pointed to selective feeding on materials that had a marine signature, especially at our offshore sampling stations. Predators fed on deposit- or suspension-feeders, with a potential selection of the latter during the highest inputs of continental materials occurring in winter

Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions