Oceans, Volume 1, Issue 2 (June 2020) – 3 articles

Over the last two decades, the scientific interest for marine geophysical surveys has shown a huge increase, mostly for multidisciplinary applicability on different studies, from historical heritage to environmental remediation. One of the main research fields carried out through marine geophysical surveys is the study of the wreckage footprints connected to the seabed perturbation. In 2018, a strategic project planned by the Italian National Government Commissioner for the remediation in the Taranto area (Southern Italy) stands as a basic sample for such issues. The project aimed at the detection of anthropogenic impact in the highly polluted Mar Piccolo and Mar Grande basins seabed, through a multidisciplinary approach involving geological, biological, chemical, engineering, and ecological studies. The main purpose of the work was to identify any potential pollution source, focusing on anthropogenic sea-floor features such as uncontrolled dumping, wrecks, or other objects of peculiar origin. To achieve the purpose of the work, field surveys were planned and performed in order to direct a general policy and accurate planning for environmental remediation activities. Different marine geophysics methods were used to characterize the main sea-floor features and to detect each anthropogenic feature. A comparative analysis of a high-resolution dataset allowed to clarify the origin of some deep depressions on the Mar Piccolo sea-bottom, which at the first instance were associated with a natural origin, as the results of the Leonardo Da Vinci wreckage and related recovering activities. High-resolution morphobathymetric, magnetometric, and seismic data revealed the story of the Italian Royal Navy battleship which sunk on 2 August 1916 as a slight footprint on the Mar Piccolo seabed but a deep historical heritage of the city of Taranto. Moreover, final results demonstrate high-resolution marine survey methodologies’ complete applicability to environmental, historical, and scientific issues. Full article

Extant cetaceans (whales, dolphins, and porpoises) and their extinct ancestors offer some of the strongest and best-known examples of macroevolutionary transition as well as microevolutionary adaptation. Unlike most reviews of cetacean evolution, which are intended to chronicle the timeline of cetacean ancestry, document the current knowledge of cetacean adaptations, or simply validate the brute fact of evolution, this review is instead intended to demonstrate how cetaceans fittingly illustrate hundreds of specific, detailed terms and concepts within evolutionary biology and evolutionary ecology. This review, arrayed in alphabetical glossary format, is not meant to offer an exhaustive listing of case studies or scholarly sources, but aims to show the breadth and depth of cetacean research studies supporting and investigating numerous evolutionary themes. Full article

Microdebris are nowadays a new emerging threat to marine ecosystems. Estuarine systems are considered sinks of contaminants, retaining these in their sediments. Nevertheless, baseline studies are essential, especially in reference estuarine systems such as the Mira Estuary, in order to establish reference conditions for other ecosystem assessment studies. Microdebris were extracted by density separation with saturated NaCl from sediment samples collected at the bare intertidal area of the lower sector of the Mira Estuary. Sediment vertical profiles showed a high abundance of microdebris, dominated by spherical and fibre-like microdebris, but also presenting metallic and uncategorized items. It was possible to observe that microdebris accumulation had its maximum concentration at a depth of 10 cm, indicating a recent increase in its usage and prevalence on this estuarine system. Comparing the item density from this work with previous studies on other aquatic ecosystems, it was found that the sediments analysed here present a very high concentration of microdebris. Although the Mira Estuary has been considered as a reference condition for the classical chemical contaminant descriptors considered in the Water Framework Directive, the data here presented indicate that this concept should be revisited adding microdebris contamination. Full article