Search Results (3)

Microplastics are plastic particles ranging in size from 1 μm to 5 mm, emitted at the source or resulting from the degradation of larger objects. Today, their global distribution is one of the major environmental problems recognized by the United Nations Sustainable Development Goals, polluting aquatic, terrestrial and atmospheric systems and requiring avant-garde solutions. Solid–liquid filtration is widely used in both industrial and biological systems, where some aquatic species are examined using very specialized filter-feeding apparatus, and when applied to industrial processes, microparticles can be separated from the water while minimizing maintenance costs, as they require less backwashing or additional energy consumption. The REMOURE project uses the Mediterranean species Mobula mobular (Bonnaterre, 1788) as a reference for the testing and optimization of low-cost microplastic filters applied to wastewater. For this purpose, a hydrodynamic test rig was designed and constructed by considering the hydraulic feeding conditions of the marine species, with a scale factor of 6. This paper presents the design conditions and the evaluation of the test results for the combination of three different variables: (1) flap disposition (two different models were considered); (2) inclination with respect to the flow direction; and (3) flow velocity. The models were printed in polyamide and videos were recorded to evaluate the behaviour of dye injection through the lobes. The videos were processed, and the results were statistically treated and used to calibrate a CFD model to optimize the filter design to be studied in a prototype wastewater treatment plant. Full article

Between 2007 and 2022, 112 specimens of newborn and young pelagic sharks were recorded in the waters of Tuscany Region, in the South Ligurian–North Tyrrhenian Seas (north-western Mediterranean basin). The sharks belonged to the Carcharhinus plumbeus (n = 14), Prionace glauca (n = 66), Isurus oxyrinchus (n = 16), Mobula mobular (n = 5) Alopias vulpinus (n = 7) and Hexanchus griseus (n = 4) species. Each animal was correctly identified thanks to the photographs or videos collected. All specimens were incidentally captured with set nets in inshore shallow waters, except bluntnose six-gill sharks, which were bycatch of deep-water bottom-trawl fishery. Body mass, sex, total length and biometric measurements were recorded in 34 baby sharks following the Mediterranean Large Elasmobranches Monitoring (MEDLEM) protocol. The presence of very evident and often non-healed umbilical scar confirmed that some of the sample specimens were newborn. Further confirmation came from the comparison between the total length observed and the size at birth known for the sampled species as reported in the literature. Some baby sharks were preserved in the Museums of Natural History of Pisa and Florence University collections. The importance of the coastal area studied as a possible shark nursery is discussed. Full article

Chondrichthyans are apex predators influencing the trophic web through a top-down process thus their depletion will affect the remaining biota. Notwithstanding that, research on chondrichthyans is sparse or data-limited in several biogeographic areas worldwide, including the Levantine Sea. We revise and update the knowledge of chondrichthyans in Cyprus based on a bibliographic review that gains information retrieved from peer-reviewed and grey literature, Global Biodiversity Information Facility (135 records of at least 18 species) and the Ocean Biodiversity Information System (65 records of at least14 species), and the citizen science project Mediterranean Elasmobranchs Citizen Observations (117 records per 23 species). Our updated checklist reports 60 species that account for about 70% of the Mediterranean chondrichthyan biota. The list includes 15 more species than the previous checklist and our study reports three new species for Cyprus waters, namely the blackmouth catshark Dalatias licha, the round fantail stingray Taeniurops grabatus, and the sawback angelshark Squatina aculeata. Our research highlights the need for conservation measures and more studies regarding the highly threatened blackchin guitarfish Glaucostegus cemiculus and the devil ray Mobula mobular, and stresses the importance for training a new generation of observers to strengthen the knowledge and conservation of elasmobranchs in the region. Full article