Accumulation Evaluation of Potential Microplastic Particles in Mytilus galloprovincialis from the Goro Sacca (Adriatic Sea, Italy)

Microplastics (MPs; <5 mm) are present throughout the marine environment and are recognized as an emerging threat to aquatic ecosystems. Filter feeding organisms, such as mussels, are considered as bioindicators of MP pollution and are useful to evaluate the potential risks of MPs to human health. The work presented shows data on potential MPs found in Mytilus galloprovincialis samples collected from the Adriatic Sea during two sampling sections (1st sampling: December 2019 and 2nd sampling: May 2020). The mussels were subjected to digestion with H2O2 individually and filtered and the MP elements found were observed using a stereomicroscope and ultimately categorized by shape, size class and color, with the aid of a digital camera and data acquisition software. The highest MP concentrations were observed in the mussels collected in December 2019 (1.11 microplastic items per gram wet weight of mussels’ tissue), highlighting the possible influence of the following two main factors: greater river discharges following adverse weather events and higher river water pollution due to industrial activities. Indeed, the second sampling was performed after the Italian lockdown, due to the COVID-19 emergency. MP fibers (50–80%) were the most abundant type of MPs identified, followed by fragments (10–40%), granules (1.5–2.5%), non-categorized shape (1–2%) and foam (<1%). The color black (50–70%) and sizes smaller than 500 µm were the most dominant characteristics recorded both in the 1st sampling (50–70%) and the 2nd survey (30–50%). These data could be overestimated, due to the lack of polymer identification. The results of this study provide further data on the importance of bivalves as environmental bioindicators with regard to the pollution of MPs in the Adriatic Sea, supporting their instrumental role as environmental bioindicators for MP pollution

Studio sull’efficacia di un sistema di depurazione a ciclo chiuso su molluschi bivalvi

Obiettivo del presente studio è stato la messa a punto ed applicazione di protocolli per la depurazione microbiologica dei molluschi bivalvi (Chamelea gallina e Mitylus galloprovincialis). Lo studio è stato articolato nelle seguenti fasi: allestimento di n. 2 vasche a circuito chiuso, per la depurazione dei molluschi bivalvi, dotate di sistemi di filtrazione meccanica, chimica e biologica; contaminazione e la depurazione dei molluschi bivalvi; determinazioni analitiche sui molluschi bivalvi e sulle acque di depurazione (analisi biometriche e microbiologiche); l’elaborazione dei dati ottenuti nella fase sperimentale. Il challenge effettuato con Escherichia coli ha mostrato un’elevata efficacia del sistema di depurazione utilizzato e, di conseguenza, la possibilità di commercializzare i bivalvi in tempi relativamente brevi. Le prove di depurazione verso Salmonella Typhimurium, sono state efficaci solo dopo 72-84 ore. I risultati ottenuti utilizzando Vibrio parahaemolyticus hanno mostrato una scarsa diminuzione della carica batterica dei bivalvi durante tutto il periodo di osservazione. Di contro, nelle sperimentazioni condotte con i mitili, i tempi di depurazione sono stati più brevi. In particolar modo, sono stati rilevati valori assimilabili alla assenza di V. parahaemolyticus dopo 36-48 ore

New protocols to improve the deposition and hatching of Sepia officinalis' eggs

The objective of this study was the development of hatching protocols in controlled conditions to obtain juveniles, in order to restock and increase the resource of Sepia officinalis. The study was divided into the following phases: development and application of artificial surfaces at specific sites of the Molise coast in Italy; induction of eggs hatching and juveniles maintenance under controlled condition; juveniles introduction into specific sites and assessment their increment; experimental data elaboration. The obtained results concerned both the effectiveness of the artificial surfaces tasted during the study and the importance of the recovery of the eggs laid on artificial surfaces (artefacts and fishing gear) for preservation and the management of the Sepia officinalis resource. The induction tests conducted on eggs hatching under controlled conditions confirmed what described in the extant literature. Water salinity was detected as the only limiting factor, with values ≤ 20% related to the absence of hatching. The described practices for harvesting and induction of hatching for the production of juvenile cuttlefish may be endorsed by the operators at relatively low cost and throughout the year, with obvious economic benefits

Dietary Preferences of Loggerhead Sea Turtles (<i>Caretta caretta</i>) in Two Mediterranean Feeding Grounds: Does Prey Selection Change with Habitat Use throughout Their Life Cycle?

According to their life stage, the loggerhead sea turtle (Caretta caretta) is found in a wide range of habitats, from neritic to more oceanic areas. Their feeding habits are expected to change as they develop, along with habitat use. Juvenile sea turtles are hypothesized to feed on pelagic species in oceanic areas, shifting to more benthic prey during the subadult and adult stages. We analyzed the gastrointestinal content from 150 loggerhead sea turtles stranded and/or bycaught along the Adriatic coast of the Abruzzo and Molise regions (n = 89) and the Tyrrhenian coast of the Lazio and Campania regions (n = 61) from 2018 to 2021. Food items were identified to the lowest taxonomic level, and the frequency of occurrence was calculated for each taxon and most recurrent species to assess changes in prey selection during the development. The marine litter was categorized, and the frequency of occurrence was calculated for the ingestion of litter. The most recurrent taxonomic prey group recorded in the Adriatic sample was Arthropoda (94%), followed by Mollusca (63%) and Chordata (34%). In the Tyrrhenian sample, loggerhead sea turtles fed mostly on Mollusca (84%), Arthropoda (38%), and Chordata (26%). Surprisingly, the Adriatic-Tyrrhenian sample groups showed similar feeding behavior between juveniles, subadults, and adults. A similar correlation has been observed concerning the ingestion of litter. Moreover, this study confirms the opportunistic feeding behavior of loggerhead sea turtles and their high adaptability