Search results for "Reef"

Unmanned aerial vehicle technology to assess the state of threatened biogenic formations: The vermetid reefs of mediterranean intertidal rocky coasts

2021

Abstract Vermetid bioconstructions are biogenic formations, built by sessile gastropod molluscs belonging to the family Vermetidae worldwide distributed, occurring in the intertidal and upper subtidal in the rocky shores. In the Mediterranean basin, they occur in complex and tridimensional structures that enhance the local biodiversity, allowing to qualify the structuring species as ecosystem engineers. Due to their ecological relevance and considerable extension along the coasts, we assessed their structural complexity using unmanned aerial vehicle (UAV) technology, as tool of littoral cartography analysis of these bioconstructions, and plaster hemispheres dissolution as a descriptor index…

Crushing predation of the spiny star Marthasterias glacialis upon the sea urchin Paracentrotus lividus

2009

Literature data report that only fish predators are able to crush sea urchin tests in Mediterranean rocky reefs. This experimental study showed that the spiny star Marthasterias glacialis is able to break Paracentrotus lividus tests and that the breaking event is more likely to occur for small-sized sea urchins than for big ones. Our results show that the role of M. glacialis in regulating P. lividus population density can be important in specific locations. They may have important implications, moreover, for the use of tethering techniques aimed at identifying predator types of sea urchins.

GLI EFFETTI DEL DISTURBO ANTROPICO SULLA TOPOGRAFIA DEL REEF A VERMETI

2011

Intertidal vermetid reefs could be affected by many human disturbances. Using a microtopography device, the authors analysed the changes induced by the accessibility on the surface topography of the reefs. Human activities seems to be able to induce a decrease in rugosity and a surface smoothing on the outer margin of the reef. These effects are proportional to the accessibility of the site.

METODOLOGIE DI ANALISI DEL PAESAGGIO NELLA VALUTAZIONE DELL’ETEROGENEITÁ STRUTTURALE NEI REEF A VERMETI

2012

Landscape ecology is a discipline that uses many indices to describe environmental dynamics as a function of structural patch organization. Application of landscape ecology methods can be a way to evaluate heterogeneity and fragmentation of a habitat. Landscape indices were applied to evaluate if the algal heterogeneity of a vermetid reef can be related to the reef structure. Results show that heterogeneity is independent from reef width, but algal patches are wider and less abundant in a large cuvette and less wide but in higher number in small cuvette.

LA DIMENSIONE FRATTALE DEI REEF A VERMETI

2012

Fractal geometry can be an useful tool to describe the structural complexity of a vermetid reef. Using fractal analysis of small surfaces, the fractal dimension for the outer rim of some vermetid reefs can be established. A positive correlation between fractal values and the density of Dendropoma petraeum is evident.

DISTRIBUTION AND CONSERVATION NEEDS OF A NEGLECTED ECOSYSTEM: THE MEDITERRANEAN VERMETID REEF

2014

Vermetid reefs are a key intertidal habitat in the Mediterranean. Despite recent evidence of local extinction in the Eastern Mediterranean, their role as habitat engineers and the high numbers of ecosystem services they provide, vermetid reefs are among the least known marine habitats of the Mediterranean. Here we present a literature-based study to assess for the first time their distribution inside the basin and provide evidence of a general lack of protection at Mediterranean scale.

Triassic/Jurassic carbonates from Western Sicily: their facies and implications for the end-Triassic biotic crisis.

2008

Paleoecological constraints on reef-coral morphologies in the Tortonian-early Messinian of the Lorca Basin, SE Spain.

2004

Coral reefs represent one of the main carbonate factories that contributed to the control of the stratigraphic architecture of carbonate platforms, which had a widespread development during the late Miocene in the paleo-Mediterranean area. The late Miocene reef complexes of the Lorca Basin in southeastern Spain are composed of five mixed siliciclastic/carbonate units, middle Tortonian to early Messinian in age. The development of coral reefs probably ceased when the first evaporitic event occurred in the basin centre in the early Messinian. This study mainly focuses on the response of reef communities and the modifications of reef organisation to global and regional parameters. At the platf…

Carbonate platform-basin systems in Sicily around the Triassic/Jurassic boundary: new data from the Campofiorito area (Sicani Mountains, western Sici…

2006

Algorithmic modeling and prototyping of a structural joint for freeform surfaces

2016

This paper describes a parametric approach in architectural design through the elaboration of a process for generating non-standard structural joints particularly suitable for the arrangement of freeform surfaces in which maximum adaptability of the system is required to join a different number of members converging in a node from generic directions. The algorithmic definitions, developed using the graphical editor Grasshopper integrated with Rhinoceros, allow the management of an integrated workflow from the conceptual design of freeform surface to the prototyping of a structural joint with 3D printing techniques.