160 research outputs found

    Deep coral forests from the Island of Sardinia

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    Forests are major ecological structures of the terrestrial environment that enhance biodiversity through different kinds of specialized relations that exist between the vegetal canopy and organisms from all animal reigns. The concept of forest has recently been transplanted in the marine environment; marine forests share all ecological features of terrestrial forests. What is actually peculiar in the marine environment is the shift from the ‘vegetal’ forest in shallow depths (within the photic zone) to the ‘animal’ forest (dwelling in the circalittoral zone) throughout the depth gradient. ‘Animal forest’ concept refers to forests entirely constituted by animals, that substitute to the vegetal canopy in the three dimensional development of the habitat. Benthic suspension feeders are, in fact, the main contributors to the habitat biomass and create important three-dimensional structures that enhance the ecosystem’s overall complexity. Among factors controlling the horizontal distribution of such ecosystems, the geomorphology of the sea bottom is thought to be a key factor in the distribution of deep-sea coral as many coral species require hard substrates, particular light and current conditions. Through the combination of non-invasive techniques such as ROV footage coupled with multi-beam surveys in contrasting geological settings, this thesis aims to test (both at species and community level) if and how distribution and composition of coral forests dwelling in the mesophotic environment (from 50 to 200m depth) could be influenced by contrasting geological settings. Uni- and multivariate as well as multiple regression analyses were used to test for differences in alpha and beta biodiversity in roche du large ecosystems and canyons, which are the most common geological features along continental margins worldwide. Results revealed that, in contrast to what was previously reported in scientific literature, red coral populations are not structured along a bathymetric gradient but other intraspecific, interspecific and environmental interactions may shape the population structure. Investigations on communities emphasized a high variability at mesoscale (10s of km) that overcomes the macroscale (100s of km). In particular, tested environmental variables explain patterns of observed diversity, that is higher within the same geological feature rather than among contrasting geological settings. Finally, a ROV survey conducted over a roche du large ecosystem off Carloforte (SW Sardinia) revealed the presence of a pristine millennial black coral forest of Leiopathes glaberrima. The investigated site is a millennial deep coral oases as well as a nursery area for the spotted catshark Schyliorhinus canicula, which deserves special protection. Our results enhance knowledge on coral forests dwelling in the mesophotic environment and provide useful insights for recasting conservation strategies, both at species and community level

    Calcolo del bilancio idrico della regione Sardegna con il modello idrologico SWAT

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    Una diminuzione del 20% delle precipitazioni nell’ultimo trentennio e perdite del 40% nella rete di distribuzione hanno causato un sensibile abbassamento dei livelli idrici medi nei laghi e negli invasi artificiali della Sardegna, con la conseguenza che negli ultimi anni le municipalità, il comparto agricolo e quello industriale hanno subito le impopolari misure di razionamento. Fino ad oggi, gli enti regionali preposti alla gestione delle acque si sono serviti di modelli a scatola chiusa di tipo black box. Tuttavia da un lato appare incerta l’applicabilità di tali modelli in aree prive di misure e dall’altro tale approccio si dimostra carente nel tenere in conto le trasformazione di uso del territorio e le variazioni climatiche. Questo studio presenta l’applicazione del modello idrologico distribuito e fisicamente basato SWAT per la stima del bilancio idrologico della regione Sardegna. La procedura di caratterizzazione del tipo e della copertura del suolo ha seguito un approccio regionale, utilizzando e valorizzando al massimo le frammentarie informazioni disponibili. Per compensare la mancanza di dati di pioggia a passo giornaliero, necessari al modello idrologico, è stato sviluppato un generatore di tempo basato sull’analisi statistica di dati climatici registrati. In base alla distribuzione spaziale delle grandezze statistiche, le stazioni pluviometriche sono state raggruppate in due gruppi. Lo studio ha prodotto una serie di archivi informatici a scala regionale, creati secondo i formati di input del modello SWAT. L’applicazione del modello ai bacini idrologici della Sardegna ha tenuto conto della qualità dell’informazione descrittiva del territorio come, ad esempio, la risoluzione spaziale delle carte di base, la densità delle reti climatiche e la qualità del dato di pioggia, al fine di garantire la massima verosimiglianza del modello concettuale con le singole realtà in studio. Il sistema informatico è stato progettato ed implementato per supportare studi ed analisi mirati alla pianificazione della gestione della risorsa idrica regionale, all’individuazione di aree soggette a stress idrico e allo studio di fenomeni legati al ciclo dell’acqua, quali il ciclo dei sedimenti e dei nutrienti.A 20% rainfall decrease in the last 30 years, prolonged periods of drought and 40% losses in the distribution pipes have substantially lowered available water reserves in Sardinia, with the result of unpopular rationing measures on municipal, industrial and agricultural uses. Up to now black-box models have been the most commonly used methodologies to estimate the regional water budget. Despite their wide use, these models have shown severe limitations in estimating watershed outlet outputs far from the monitoring stations and in covering climate changes properly. In this study, we present the application of the hydrological distributed SWAT model to evaluate the water budget at the regional scale. The model parameterizations with regards to the land cover and soil type are estimated at the regional scale on the basis of available geographic data. In order to generate weather daily inputs for the SWAT model a weather generator has been developed on the basis of a statistical analysis of the Sardinian climatic data. Through a clusterization procedure the climatic gages have been grouped into two homogeneous groups. The regional databases have been formatted in the SWAT fashion. The resulting model input data along with the watershed and HRU spatial discretization criteria have been carefully checked to ensure global consistency at the overall scale. The informatics system has been developed and designed to support decision related to the management of the water resources, to identify areas under water stress, or to evaluate complementary phenomena related to the water cycle as the sediment and the nutrient fate at the catchment’s scale.29-38Pubblicat

    Persistence of pristine deep-sea coral gardens in the Mediterranean Sea (SW Sardinia)

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    Leiopathes glaberrima is a tall arborescent black coral species structuring important facies of the deep-sea rocky bottoms of the Mediterranean Sea that are severely stifled by fishing activities. At present, however, no morphological in vivo description, ecological characterization, age dating and evaluation of the possible conservation actions have ever been made for any population of this species in the basin. A dense coral population was reported during two Remotely Operated Vehicle (ROV) surveys conducted on a rocky bank off the SW coasts of Sardinia (Western Mediterranean Sea). L. glaberrima forms up to 2 m-tall colonies with a maximal observed basal diameter of nearly 7 cm. The radiocarbon dating carried out on a colony from this site with a 4 cm basal diameter revealed an approximately age of 2000 years. Considering the size-frequency distribution of the colonies in the area it is possible to hypothesize the existence of other millennial specimens occupying a supposedly very stable ecosystem. The persistence of this ecosystem is likely guaranteed by the heterogeneous rocky substrate hosting the black coral population that represents a physical barrier against the mechanical impacts acted on the surrounding muddy areas, heavily exploited as trawling fishing grounds. This favorable condition, together with the existence of a nursery area for catsharks within the coral ramifications and the occurrence of a meadow of the now rare soft bottom alcyonacean Isidella elongata in small surviving muddy inclaves, indicates that this ecosystem have to be considered a pristine Mediterranean deep-sea coral sanctuary that would deserve special protection

    Onboard Scientific Observers Provide a Realistic Picture of Harvesting and Management Priorities for the Precious Red Coral (Corallium rubrum L.)

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    Mediterranean red coral Corallium rubrum is considered the most precious coral worldwide. Harvesting activities are performed by licensed scuba divers and managed through the recent pan-Mediterranean management plan issued by General Fisheries Commission for the Mediterranean (GFCM) along with measures locally enacted, imposing limits on licenses, harvesting season, minimum depth of dive, and size. The use of Remotely Operated Vehicles (ROVs) is prohibited, with the only exception being for scientific purposes. Despite measures already in force, the implementation of additional management tools has been recently recommended. This article reports results from the first monitoring campaign on C. rubrum harvesting based on ROVs for seabed exploration and Onboard Scientific Observers (OSOs), carried out from 2012 to 2015 along the coast of Sardinia (Mediterranean Sea—Western basin). More than 450 dives were monitored, confirming how ROV's support eases the scouting of exploitable banks, leading to increases in catches. OSOs reported the collection of colonies below the minimum reference size and catches/dive above limits. Onboard observers collected data also on colony diameter, which is crucial for the estimation of population size structure and exploitation status. OSOs proved to be valid tools in providing additional and reliable information on red coral harvesting, thus deserving to be included among mandatory measures for the sustainable exploitation of red coral in the Mediterranean Sea

    Bio-Ecological Features Update on Eleven Rare Cartilaginous Fish in the Central-Western Mediterranean Sea as a Contribution for Their Conservation

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    Cartilaginous fish are commonly recognized as key species in marine ecosystems for their fundamental ecological role as top predators. Nevertheless, effective management plans for cartilagi- nous fish are still missing, due to the lack of knowledge on their abundance, distribution or even life-history. In this regard, this paper aims at providing new information on the life-history traits, such as age, maturity, reproductive period, in addition to diet characteristics of eleven rare cartilagi- nous fish inhabiting the Central-Western Mediterranean Sea belonging to the orders Chimaeriformes (Chimaera monstrosa), Hexanchiformes (Heptranchias perlo and Hexanchus griseus), Myliobatiformes (Aetomylaeus bovinus and Myliobatis aquila), Rajiformes (Dipturus nidarosiensis and Leucoraja circu- laris), Squaliformes (Centrophorus uyato, Dalatias licha and Oxynotus centrina) and Torpediniformes (Tetronarce nobiliana), useful for their assessment and for future management actions. Particularly, the present paper provides for the first time the age estimation of D. nidarosienis and L. circularis which were both found capable of becoming older than ten years. In addition, the present study updates the sizes of first maturity of C. uyato and D. licha, which appeared to be capable of reproducing earlier than what was previously hypothesized, representing very valuable information for a better understanding of these rare species populations status and, eventually, their conservation. On the basis of the stomach content analysis, it was possible to identify five different predator groups

    On the presence of the Endangered white skate Rostroraja alba in Sardinian waters

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    The white skate Rostroraja alba is assessed by the International Union for Conservation of Nature as Endangered globally and is now considered rare in the Mediterranean. This species has never been recorded in Sardinian seas (central western Mediterranean), but an empty eggcase was collected on a sandy bottom off the western Sardinia coasts during the MEDiterranean International Trawl Survey (MEDITS) program in 2019. A morphometric and morphological description of the Sardinian eggcase, after a comparison with measurements from other Mediterranean and Atlantic specimens, showed it to be clearly ascribable to Rostroraja alba

    Body-scaled action in obesity during locomotion: Insights on the nature and extent of body representation disturbances

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    Objective Conscious perception of our own body, also known as body image, can influence body-scaled actions. Certain conditions such as obesity are frequently accompanied by a negative body image, leaving open the question if body-scaled actions are distorted in these individuals. Methods To shed light on this issue, we asked individuals affected by obesity to process dimensions of their own body in a real action: they walked in a straight-ahead direction, while avoiding collision with obstacles represented by door-like openings that varied in width. Results Participants affected by obesity showed a body rotation behavior similar to that of the healthy weighted, but differences emerged in parameters such as step length and velocity. Conclusion When participants with obesity walk through door-like openings, their body parts rotation is scaled according to their physical body dimensions; however, they might try to minimize risk of collision. Our study is in line with the hypothesis that unconscious body-scaled actions are related to emotional, cognitive and perceptual components of a negative body image

    Ichthyosauria. Soluzioni multidisciplinari per la lettura integrata dell’Appennino emiliano a partire dal rinvenimento dell’ittiosauro di Neviano degli Arduini

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    The ‘Inter Amnes. Archeologia tra Enza, Parma e Baganza’ project in the framework of the Programma ‘S.F.E.R.A. Spazi e Forme dell’Emilia Romagna Antica’ of the University of Parma has promoted a series of survey campaigns on the Parma Apennines, previously never involved in surface reconnaissance. The research was conducted by a multidisciplinary team aimed at highlighting the various peculiarities of the territory from a geological, archaeological, historical, and paleontological point of view, with a view to reconstruct the evolutionary dynamics of the landscape. Among the most relevant discoveries is the discovery of ten fossil ichthyosaur caudal vertebrae from a ‘Chaotic Complex’ in the Apennines of western Emilia and found during the reconnaissance for the mapping of fossil deposits. Compared to the great majority of vertebrate remains from the units of the ‘Chaotic Complex’, usually represented by isolated or damaged skeletal elements, the specimen preserves the original relationships between the different vertebral elements. The biostratigraphic analysis of the fossil made it possible to recognize a micro-paleontological association attributable to the Aptian stage (Lower Cretaceous). Starting from the systematic palaeontological analysis, the discovery is also brought back here to its context for an integrated, diachronic, and multidisciplinary re-reading of the ancient landscapeIl progetto   Inter Amnes. Archeologia tra Enza, Parma e Baganza nella cornice del Programma S.F.E.R.A. Spazi e Forme dell’Emilia Romagna Antica dell’Università di Parma, ha promosso una serie di campagne di survey sull’Appennino parmense, in precedenza mai interessato da ricognizioni di superficie.  Le ricerche sono state condotte da un team multidisciplinare volto a mettere in luce le diverse peculiarità del territorio sotto il profilo  geologico, archeologico, storico, paleontologico, nella prospettiva di una ricostruzione delle  dinamiche evolutive del paesaggio. Tra i rinvenimenti più rilevanti si segnala la scoperta di 9 vertebre caudali fossili di Ittiosauro provenienti da un “Complesso Caotico” negli Appennini dell’Emilia occidentale ritrovate durante le perlustrazioni per la mappatura dei giacimenti fossiliferi. Rispetto alla grande maggioranza dei resti di vertebrati delle unità del "Complesso Caotico", solitamente rappresentati da elementi scheletrici isolati o danneggiati, l'esemplare conserva le relazioni originali tra i diversi elementi vertebrali. Configura quindi un modello che richiede impostazioni deposizionali relativamente a bassa energia e quindi sfida il tradizionale scenario “ad alta energia” per la genesi dei fossili del “Complesso Caotico”. La presenza sia di ittiosauri e di talattosuchi nell'Aptiano d'Italia supporta la persistenza nella Tetide occidentale della comunità di rettili pelagici di grosso corpo tipici del Giurassico medio e tardo-lungo e la prima metà del Cretaceo inferiore. Muovendo dall’analisi paleontologica sistematica il rinvenimento viene ricondotto in questa sede anche al suo contesto per una rilettura integrata, diacronica e multidisciplinare del paesaggio antico

    An Integrated Multi-Sensor Approach for the Remote Monitoring of Parkinson’s Disease

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    The increment of the prevalence of neurological diseases due to the trend in population aging demands for new strategies in disease management. In Parkinson's disease (PD), these strategies should aim at improving diagnosis accuracy and frequency of the clinical follow-up by means of decentralized cost-effective solutions. In this context, a system suitable for the remote monitoring of PD subjects is presented. It consists of the integration of two approaches investigated in our previous works, each one appropriate for the movement analysis of specific parts of the body: low-cost optical devices for the upper limbs and wearable sensors for the lower ones. The system performs the automated assessments of six motor tasks of the unified Parkinson's disease rating scale, and it is equipped with a gesture-based human machine interface designed to facilitate the user interaction and the system management. The usability of the system has been evaluated by means of standard questionnaires, and the accuracy of the automated assessment has been verified experimentally. The results demonstrate that the proposed solution represents a substantial improvement in PD assessment respect to the former two approaches treated separately, and a new example of an accurate, feasible and cost-effective mean for the decentralized management of PD
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