• European Marine Science
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Loggerhead sea turtles are ancient marine reptiles inhabiting the oceans worldwide. They are colonized by microorganisms both in the gastrointestinal tract and on their carapace and skin. In this thesis that consists of four scientific publications, the loggerhead sea turtle-associated diatom and bacterial communities were investigated by high-throughput sequencing of chloroplast rbcL gene and 16S rRNA gene, and cultivation. The culture-independent approach has shown that loggerheads harbor diverse but stable bacterial communities in their cloaca, and that the oral microbiota reflects the turtle’s environment. The carapace and skin harbor complex microbial communities often rich in as yet unclassified taxa. Diatoms isolated from carapace and skin were cultivated as xenic monocultures and further characterized using morphology and molecular techniques to elucidate their identity and phylogeny. Novel diatom taxa were discovered, often belonging to the genera Craspedostauros, Fallacia, or Amphora genus. Cultivated diatoms also enabled the characterization of the phycosphere and isolation of diatom-associated bacterial strains. Glavate želve su drevni morski gmazovi koji nastanjuju svjetska mora i oceane. Njihov probavni sustav te oklop i koža kolonizirani su mikroorganizmima. U ovoj disertaciji čiji su rezultati predstavljeni u sklopu četiri znanstvene publikacije, mikrobne zajednice dijatomeja i bakterija glavatih želvi su analizirane koristeći molekularne metode sekvenciranja visoke protočnosti kloroplastnog rbcL gena i 16S rRNA gena te kultiviranjem. Rezultati metoda neovisnih o kultivaciji su pokazali da su bakterijske zajednice u kloaki glavate želve raznolike ali stabilne te da oralna mikrobiota reflektira okoliš u kojem se kornjača nalazi. Karapaks i koža podloga su složenim mikrobnim zajednicama u kojima su često prisutni još uvijek nepoznati mikroorganizmi. Dijatomeje izolirane s karapaksa i kože kultivirane su kao ksenične monokulture te su korištene morfološke i molekularne metode za njihovu identifikaciju i određivanje filogenije. Otkrivene su nove svojte dijatomeja unutar rodova Craspedostauros, Fallacia i Amphora. Kultivacija dijatomeja također je omogućila analizu fikosfere te izolaciju pripadajućih bakterijskih sojeva.

Marine ecosystems are essential to life on Earth, but they constantly face the consequences of human activities. International conventions such as the Convention for the Protection of the Marine Environment of the North-East Atlantic and directives such as the Marine Strategy Framework Directive urge countries to improve monitoring and conservation of ocean health. Bioindicator species can help us assess the health status of ecosystems, and while there are many good candidates among the hundreds of extant shark species, the blue shark (Prionace glauca) stands out as one of the most widely distributed and socioeconomically important shark species in the world. This work highlighted the importance of blue shark in the Portuguese elasmobranch fisheries and the need for better management strategies. Sixty sharks were sampled in the Northeast Atlantic and the results evidenced high contaminant body burdens, with two thirds of the sharks presenting concentrations of Hg and/or Pb in their muscle above safety thresholds for human consumers. Location was the main factor influencing contaminants accumulation, with sharks captured closer to the continental shore presenting higher contamination when compared with sharks from more oceanic locations. A similar pattern was observed in biomarker responses, with the sharks from areas closer to the continental shore (i.e., more contaminated) exhibiting more pronounced responses. Additionally, the amount of damaged DNA in the liver and protective alterations in the gills correlated strongly and positively with contaminants in sharks from the more contaminated area (i.e., As, PCBs, and PBDEs). Ultimately, this thesis validated the potential of blue shark as a bioindicator of pollution in the Atlantic, and the specific biomarkers with potential in marine biomonitoring surveys, whilst contributing useful data for better management and conservation.

La tesi affronta e analizza le implicazioni giuridiche di diritto internazionale emergenti dal crescente uso di navi a navigazione autonoma. Tale novità tecnologica pone particolari criticità concernenti l'assenza attuale di disposizioni ad hoc e la difficoltà di applicare le pre-esistenti regole concernenti la navigazione internazionale. La tesi si struttura in tre capitoli, ciascuno dei quali affronta l'analisi di un settore del diritto internazionale particolarmente problematizzato dall'utilizzo di navi autonome. Il prima capitolo osserverà se e come le norme sulla sicurezza della navigazione si applicano alle navi automatiche. Il secondo capitolo investiga la possibilità di estendere le norme che ripartiscono i poteri giurisdizionali degli Stati all'uso di navi a guida autonoma. Il terzo capitolo osserva quali criticità emergono dall'uso di queste nuove imbarcazioni con riferimento alle norme internazionali volte al salvataggio delle persone "in distress". Infine, le ultime pagine della tesi riportano alcune riflessioni finali volte ad inquadrare l'analisi giuridica svolta in una prospettiva più generale, cercando di comprendere quali passi dovranno essere percorsi dalla comunità internazionale al fine di far fronte alle criticità derivanti dalla costruzione e utilizzo di navi autonome. This thesis addresses and analyzes the legal implications of international law arising from the increasing use of self-navigating ships. This technological innovation poses particular criticalities concerning the current absence of ad hoc provisions and the difficulty of applying the pre-existing rules concerning international navigation. The thesis is structured in three chapters, each of which deals with the analysis of an area of international law particularly problematized by the use of autonomous ships. The first chapter will look at whether and how the rules on safety of navigation apply to autonomous ships. The second chapter investigates the possibility of extending the rules apportioning states' jurisdictional powers to the use of self-driving ships. The third chapter observes what critical issues arise from the use of these new vessels with respect to international norms aimed at rescuing people "in distress." Finally, the last pages of the thesis report some final reflections aimed at framing the legal analysis carried out in a more general perspective, trying to understand what steps should be taken by the international community in order to cope with the critical issues arising from the construction and use of autonomous ships.