Benthic ecosystem functioning

The main aim of this doctoral research project was to assess the benthic ecosystem functioning in areas subjected to multiple and diffuse impacts. The Aeolian Islands, originated by the volcanic activity and characterised by continuous gas emissions and presence of thermal vents on the surrounding seabed, represent a good natural laboratory for global warming and carbon capture and storage (CCS) leakage studies. The aim of this work was to investigate to what extend the high CO2 alone and in combination with the high temperature affects the microphytobenthic abundance and its community composition (Chapter 1). A further objective was to detect a possible change in the primary production rate in relation with these two variables. Higher microphytobenthic densities were recorded at the vent stations and values were even more pronounced in relation with high temperature. On the other hand, high microphytobenthic abundances were coupled with low community richness and diversity. The gross primary production estimates were strongly coupled with the microphytobentic abundance values. We observed several diatoms with morphological deformities, The Port of Trieste represents an area with a diffuse sediment contamination as it is subjected to diverse impacts: the shipbuilding activities, the iron and steel plant, the petroleum industry and the port activities. The aim of this study (Chapter 2) was to detect any variation in the structure of the microbenthic community, both as active phototrophic and resting microbenthos, and the possible differences in the primary production and respiration at stations subjected to different anthropogenic impacts. The total microbenthic abundance did not vary among stations. On the other hand, the structure of the community gave more information. In particular, the analysis based on the active and resting microbenthic community structure highlighted a clear separation among stations close to the productive activities from the more distant ones and the reference station, indicating a contamination effect on those communities. As an example of an area severely contaminated by heavy metals and synthetic organic compounds, the Mar Piccolo of Taranto was chosen. Firstly, the microphyto- and macrozoobenthic communities were investigated and a marked influence of contamination on the abundance and biodiversity of those two communities was detected (Chapter 3). To further asses the overall trophic status of the benthic ecosystem, an integrated study of the active phototrophic and resting microbenthic stages, combined with the main photoautotrophic pathways, was conducted (Chapter 4). Furthermore, although the Mar Piccolo is very shallow, the benthic system was scarcely productive, likely as a consequence of the accumulated contaminants in the surface sediments that probably interfere with the proper functioning of the benthic ecosystem. Contrary to the benthic ecosystem, the pelagic one was very productive and a clear seasonal succession of different sized plankton phototrophs was observed (Chapter 5). To have a better overall view and provide some insights into the benthic-pelagic coupling, the primary production and heterotrophic prokaryotic production in the water column were integrated with those in the sediments and related to the origin of the organic matter pools based on the analysis of stable isotopes (Chapter 6)

“New Alien Mediterranean Biodiversity Records” (November 2021)

This Collective Article includes records of 29 alien and cryptogenic species in the Mediterranean Sea, belonging to eight Phyla (Rhodophyta, Ochrophyta, Cnidaria, Annelida, Mollusca, Arthropoda, Echinodermata, and Chordata) and coming from 11 countries. Notes published here can be divided into three different categories: occupancy estimation for wide areas, new records for the Mediterranean Sea, and new records of species expanding within the Mediterranean Sea. The first category includes a visual survey held along the coastline of Peloponnese (Greece), which yielded records of 15 species. The second category includes the first Mediterranean records of the Coho salmon Oncorhynchus kisutch (Greece) and of the Arabian monocle bream Scolopsis ghanam (Tunisia). The third category includes new records for countries (Ganonema farinosum in Malta, Cassiopea andromeda in Libya, Cingulina isseli in Greece, Okenia picoensis in Italy, Callinectes sapidus in Slovenia, Charybdis cf. hellerii in Malta, Urocaridella pulchella in Cyprus, Ablennes hians and Aluterus monoceros in Lebanon, and Fistularia petimba in Greece and Lebanon), new records for MSFD areas or regional seas (Septifer cumingii in the Greek Ionian Sea and F. petimba in the Marmara Sea), and confirmation of old, doubtful, or spurious records/statements (Branchiomma luctuosum in Tunisia, Thalamita poissonii in the Saronikos Gulf, and Pterois miles in Albania). Noteworthy, the three new records of F. petimba suggest that it may soon spread further in the Mediterranean Sea, as already happened for its congeneric Fistularia commersonii. Distributional data reported here will help tracing colonization routes of alien species in the basin and may facilitate the development of mitigation measures

Why Do Only Males of Mawia benovici (Pelagiidae: Semaeostomeae: Scyphozoa) Seem to Inhabit the Northern Adriatic Sea?

This manuscript presents four new observations of the jellyfish Mawia benovici in the Adriatic Sea. This new species was recently identified as Pelagia benovici by Piraino et al. (2014) and then placed in the new genus Mawia by Avian et al. 2016. This species is rare and is almost exclusively observed in the Adriatic Sea. Interestingly, the majority of observations refer to males only. Few studies have addressed the issue of sex determination in Syphozoa in particular, as sex identity can only be determined at the medusa stage. Unfortunately, the rarity of M. benovici and the lack of female specimens have so far prevented indispensable laboratory studies to clarify its life cycle. Still, we tried to propose an explanation for our field observations

New records of rare species in the Mediterranean Sea (December 2022)

This Collective Article presents information on 20 taxa belonging to five (5) Phyla: Cnidaria (2), Mollusca (8), Arthropoda (4), Echinodermata (1) and Chordata (5) recorded from the Alboran Sea to the Levantine Sea. These new records were found in seven (7) different ecoregions as follows: Alboran Sea: new record of the rare football octopus Ocythoe tuberculata in the harbour of Algeciras (Spain); Western Mediterranean Sea: first record of the isopod Arcturinella deltensis in the Ligurian Sea, and the third in the whole Mediterranean Sea; third Mediterranean site for the Muricidae Coralliophila ahuiri along the Italian coasts (Alghe-ro); first and westernmost record of the goby Corcyrogobius liechtensteini from the Iberian Peninsula; new record of the sea slug Glaucus atlanticus from the coast of the Iberian Peninsula; first and easternmost record of Holothuria (Vaneyothuria) lentiginosa lentiginosa along the Italian coasts; Tunisian Plateau/Gulf of Sidra: seventh record of the oceanic squid Thysanoteuthis rhombus in Tunisia, and first for the Gulf of Gabes. Ionian Sea: second occurrence of the Atlantic tripletail Lobotes surinamensis in the Ionian Sea and first record from the Strait of Messina area; new record of the rare sea elephant Pterotrachea coronata from the Strait of Messina; Adriatic Sea: first record of a facies of football ascidian Diazona violacea in the South Adriatic Sea (Tremiti Island, Italy); two records of the sevengill shark Heptranchias perlo in Croatian waters after more than 70 years of absence of documented records in this area; first known occurrence of the nudibranch Jalonus hyalinus in Slovenian waters and also the first known occurrence of this species in the Adriatic Sea; first record of the nudibranch Okenia elegans in Slovenian waters; Aegean Sea: First record of the parasitic isopod Nerocila milesensis along Greek coasts (Crete island) as well as the second record world-wide; additional record of the brachyuran Paragalene longicrura collected from the Saronikos Gulf (Greece); first record of the siphonophore Rhizophysa filiformis in Greek waters as well as the second record of this species in the eastern Mediterranean basin; new record of the rare and protected angelshark Squatina aculeata along Turkish coasts; Levantine Sea: first record of the marine amphipod Caprella andreae in the Levantine Mediterranean shore of Israel, based on both morphological and molecular data; first occurrence of the cephalopod Tremoctopus violaceus along Turkish coasts, which confirms its presence in the north-eastern coasts of Turkey; record of a bloom of the thermophilic jellyfish Pelagia noctiluca in the north Levantine Sea