• Energy Research

This volume contains the main results of the EC FP7 “The Ocean of Tomorrow” Project CoCoNet, divided in two sections: 1) a set of guidelines to design networks of Marine Protected Areas in the Mediterranean and the Black Seas; 2) a smart wind chart that will allow evaluating the possibility of installing Offshore Wind Farms in both seas. The concept of Cells of Ecosystem Functioning, based on connectivity, is introduced to define natural units of management and conservation. The definition of Good Environmental Status, as defined in the Marine Strategy Framework Directive, is fully embraced to set the objectives of the project, by adopting a holistic approach that integrates a full set of disciplines, ranging from physics to bio-ecology, economics, engineering and many sub-disciplines. The CoCoNet Consortium involved scientist sfrom 22 states, based in Africa, Asia, and Europe, contributing to build a coherent scientific community. peer-reviewed

Madrepora oculata and Lophelia pertusa are the two main ecosystem engineering, scleractinian cold-water corals (CWC) found in Mediterranean canyons. Factors controlling CWC distribution in the Mediterranean Sea are not yet fully understood in spite of such ecosystems being recognized as sensitive habitats by the General Fisheries Commission for the Mediterranean. As they are threatened by fishery activity, they are subject to management and protection measures. In order to contribute towards identifying the major drivers governing CWC distribution at local scale, which is a prerequisite for proper management, we focused our attention on two canyons: (1) the Cassidaigne canyon, located in the eastern part of the Gulf of Lion, in which CWC ecosystems have settled in an upwelling environment and form large colonies, and (2) the Bari Canyon System, in the southwestern Adriatic, a site of coral growth that has been hypothesized to respond to hydrographic processes, including the cascading of North Adriatic Dense Water. The objective of our study was to combine several ecological variables to describe the environmental conditions in favor of CWC settlement and growth: (1) CWC observations, extracted from geo-referenced underwater videos, (2) seafloor characteristics derived from high-resolution bathymetry, (3) data on local hydrodynamic conditions (from high resolution hydrodynamic models). Habitat suitability models were used to identify the main variables driving CWC distribution. Models based on presence-only data (Maxent and ENFA) and on presence-absence data (GLMs) were fitted and compared. Seafloor ruggedness was identified to be the major factor driving CWC distribution in both canyons with the three methods. Two hydrodynamic variables (mean temperature and current velocity) were the second most important predictors for explaining CWC settlement and growth. Suitable areas for CWC habitat occurrence were mapped for both canyons. Spatial distributions were generally predicted at the same locations, although the GLM gave less realistic results in the Bari canyon system probably due to the limited range cover of the entire environmental conditions by the absence points, suggesting that the Maxent and ENFA models were more efficient. These theoretical distributions will help in the assessment of potential habitat extent in the deep-sea and also in the scheme of the Marine Strategy Framework Directive (MSFD).

After the end of the Last Glacial Maximum, 450 km2 of former terrestrial and coastal landscape of the Maltese Islands was drowned by the ensuing sea level rise. In this study we use high resolution seafloor data (multibeam echosounder data, seismic reflection profiles, and Remotely Operated Vehicle imagery) and bottom samples to reconstruct ~ 300 km2 of this submerged Maltese paleolandscape. The observed paleolandscape is exceptionally well preserved and comprises former coastal landforms – (i) fault-related escarpments, (ii) paleoshore platforms and associated shorelines, (iii) paleoshoreline deposits, and (iv) mass movement deposits – and former terrestrial landforms – (v) river valleys, (vi) alluvial plains, (vii) karstified limestone plateaus, and (viii) sinkholes. These elements indicate that the paleolandscape has been primarily shaped by tectonic activity combined with fluvial, coastal, slope instability and karstic processes; these are the same processes the shaped the current terrestrial and coastal landscape. By correlating the identified landforms with the timing of known changes in sea level during the last glacial cycle, we infer that the alluvial plains and the shallowest limestone plateaus had up to 100 kyr to develop, whereas the paleoshoreline deposits are likely to have formed between 28 kyr and 14 kyr. The most prominent paleoshore platforms, shorelines and river valleys were generated between 60 kyr and 20 kyr. Fluvial erosion is likely to have been prevalent during periods of low sea level (Last Glacial Maximum and stadial conditions during MIS 3), whereas karst processes should have been more effective during warm and humid interstadial periods. Our results have implications for improving the characterization of past environments and climates, as well as providing a much needed background for prehistoric and geoarcheological research in the central Mediterranean region.

The South West Adriatic Margin (SAM) includes a steep and morphologically complex continental slope stretching about 600 km from the Pelagosa sill to the Otranto strait. The margin is clearly dissected by submarine slides, active fault systems (e.g.: the Gondola deformation belt), numerous shallowly incised and relatively straight canyons located south of Bari Canyon, and a variety of large-scale erosional and depositional features. This area is seasonally impacted by dense shelf water forming in the North Adriatic through wind-forced winter cooling, moving south along the western side of the basin, and cascading across the South Adriatic slope.The area has been investigated through multibeam surveys integrated by high-resolution seismic stratigraphic data resolving glacial and post-glacial deposits. This paper gives a detailed and comprehensive description of the SAM seafloor morphology to document how the process of dense shelf water cascading concurs to a thorough "restyling" of the submarine landscape by interacting with the pre-existing and markedly differentiated morphologies and sediment distribution. We focus on depositional and erosional features such as: giant sediment drifts down to 1200 m water depth, muddy and sandy sediment waves, comet marks against pre-existing slide blocks, furrow fields against steep slopes, large scours at the shelf edge and large erosional moats adjacent to major morphological barriers. The analysis of the bedform orientation and spatial distribution indicates that the downslope-cascading bottom-currents (dominantly directed to the SE) encounter a straight upper slope, oriented north south in the north and progressively more east west proceeding to the south; as the slope orientation becomes more E-W it also appears more dissected by small-scale canyons, active during glacial times. In the latter area, therefore, the dense shelf waters follow a slope-parallel direction almost perpendicular to the pre-existing slope canyons. As a consequence, erosional furrows develop perpendicular to the canyon flanks and some of the canyon heads become disconnected from the main canyon downslope.

The south Adriatic shelf offshore of the redominently carbonate Apulian coast is characterized by a peculiar rough topography interpreted as relic karst formed at a time of lower sea level. The study area covers a surface of about 220 km2 , with depths ranging from 50 to 105 m. The most relevant and diagnostic features are circular depressions a few tens to 150 m in diameter and 0.50 to 20 m deep thought to be dolines at various stages of evolution. The major doline, Oyster Pit, has its top at about 50 m water depth and is 20 m deep. It is partly filled with sediments redeposited by episodic mass failure from the doline’s flank. Bedrock samples from the study area document that Plio-Pleistocene calcarenites, tentatively correlated with the Calcarenite di Gravina Fm, are a prime candidate for the carbonate rocks involved in the karstification, although the presence of other units, such as the Peschici or Maiolica Fms, is not excluded. The area containing this subaerial karst landscape was submerged about 12,500 years ago as a result of the postglacial transgression over the continental shelf.

Within the Mediterranean region, the Adriatic basin is one of the key sites for the formation and spreading of dense shelf water. Once formed in the northern shallow region as a response to strong, wintry cold air outbreaks, dense water masses move southeastwards as bottom-hugging gravity currents, eventually reaching the south Adriatic continental margin. A fraction of the dense water mass is thus intercepted by the shelf break, whence it flows down the continental slope driven by its negative buoyancy and interacting with ambient water and seafloor topography. This process generates a wide variety of dynamics and morphological features, such as erosional moats, furrows, giant comet marks, sediment drifts, and sediment waves. In this study we merge the outcomes of a state-of-the-art wave-ocean coupled numerical model with the geological evidence from the analysis of southern Adriatic bedform patterns. The model was run to reproduce an exceptional cold event that occurred in winter 2012, and benefits from a high-resolution bottom topography produced from data collected during recent bathymetric surveys. Model results allow the identification of flow pathways along and across the continental shelf and slope, with particular emphasis on the role of large-scale margin geometry in controlling morphodynamic processes and its implications in terms of resolution requirements for modelling purposes. Although modelled overall water fluxes and basin renewal ratios are mostly controlled by regional circulation and large-scale morphology, local topographic features and singularities appear crucial in triggering, concentrating and modulating bottom currents dynamics and sediment transport towards the South Adriatic Pit, as well as enhancing mixing and entrainment of ambient water. As long as this degree of information is provided within the bathymetric constraint, modelled hydrodynamic pathways in the study case are consistent with observed bedform morphology and their spatial pattern. For different zones in the continental slope, temporal variability of the flows has been investigated, permitting to disentangle the relative contribution of dense water cascading and background circulation at the basin and sub-basin scale in controlling bedform dynamics.This study gives a first quantitative insight on the hydrodynamic mechanisms responsible for South Adriatic Margin reshaping, suggesting a modelling approach to the interpretation of the high-resolution bathymetric and stratigraphic data made available by recent survey technologies.