Geomorphology of the Continental Shelf of Tavolara Island (Marine Protected Area 'Tavolara- Punta Coda Cavallo' – Sardinia
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Journal of Maps ISSN: (Print) 1744-5647 (Online) Journal homepage: https://www.tandfonline.com/loi/tjom20 Geomorphology of the continental shelf of Tavolara Island (Marine Protected Area ‘Tavolara- Punta Coda Cavallo’ – Sardinia NE) Giacomo Deiana, Florian Holon, Antonietta Meleddu, Augusto Navone, Paolo E. Orrù & Enrico M. Paliaga To cite this article: Giacomo Deiana, Florian Holon, Antonietta Meleddu, Augusto Navone, Paolo E. Orrù & Enrico M. Paliaga (2018): Geomorphology of the continental shelf of Tavolara Island (Marine Protected Area ‘Tavolara-Punta Coda Cavallo’ – Sardinia NE), Journal of Maps, DOI: 10.1080/17445647.2018.1533895 To link to this article: https://doi.org/10.1080/17445647.2018.1533895 © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps View supplementary material Published online: 11 Dec 2018. Submit your article to this journal Article views: 80 View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tjom20 JOURNAL OF MAPS https://doi.org/10.1080/17445647.2018.1533895 Science Geomorphology of the continental shelf of Tavolara Island (Marine Protected Area ‘Tavolara-Punta Coda Cavallo’–Sardinia NE) Giacomo Deianaa, Florian Holonb, Antonietta Meleddua, Augusto Navonec, Paolo E. Orrù d and Enrico M. Paliagaa aDipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Cagliari, Italy; bAndromede Oceanologie, Carnon, France; cArea Marina Protetta “Tavolara – Punta Coda Cavallo”–Ministero dell’Ambiente, Olbia, Italy; dDipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, CoNISMa, Cagliari, Italy ABSTRACT ARTICLE HISTORY In this document a geological – geomorphological map in scale 1: 25,000 is presented. The Received 25 January 2018 study area is located inside the Protected Marine Area Tavolara – Punta Coda Cavallo, in Revised 18 September 2018 north-eastern Sardinia. The study was done through integrated analysis of multibeam Accepted 5 October 2018 2 bathymetric and very high-resolution side scan sonar data, acquired in an area of 163 km KEYWORDS with the purpose of mapping the main biocoenoses and with particular reference to the Marine geomorphology; coralligenous bioconstructions and the distribution of Posidonia oceanica. The interpretative Continental shelf; Beach hypotheses, based on the analysis of geophysical data, have been validated through diving rocks; Habitat mapping; surveys. This map represents a fundamental knowledge base and it constitutes an important Posidonia oceanica; Sardinia technical-scientific support for long-term planning and management of the studied seabed. 1. Introduction It has been estimated that only 5–10% of the seafloor Marine habitat mapping provides the spatial frame- is mapped at a comparable resolution to similar studies work for ecosystem-based management (EBM). Its on land (Wright & Heyman, 2008). Furthermore, mar- increasing prominence, in international policy and ine ecosystems are poorly described compared to their regional and national management organizations, terrestrial counterparts. On land, the proportion of highlights its growing acceptance especially as a tool unknown habitats has been estimated as 17% whilst for designing and delineating MPA (Marine Protected for the marine realm it has been estimated as 40% Area). The management priorities of protecting biodi- (EC, 2007). Numerous research highlight the strong versity and developing sustainable use solutions, need relationship between habitat and biocoenosis (Curley, to be implemented with the use of credible scientific Kingsford, & Gillanders, 2002; Friedlander & Parrish, information. One of the main goals of marine spatial 1998; Gratwicke & Speight, 2005; Moore, Van Niel, & management is to promote a sustainable use of marine Harvey, 2011; Williams et al., 2008). Information resources while not putting marine biodiversity and about benthic habitats and biological communities habitats at risk. Objectives for marine biodiversity are important for the implementation of ecosystem- and habitats are stated in the Biodiversity Convention, based management of the sea and in assessing the con- Habitat Directive and the Marine Strategy Framework sequences of human activities, and assessment has to Directive (EC, 2008a; EEC, 1992; UN, 1992). have a clear link to the management objectives (Buhl- Effective planning which aspires to be ‘representa- Mortensen et al., 2012; Steltzenmüller et al., 2013). tive’ and ‘adequate’ requires spatial knowledge of Habitat mapping is a support for government spatial biota, habitat, or suitable surrogates at a scale relevant marine planning, management, and decision making; to an MPA (Leslie, Ruckelshaus, Ball, Andelman, & and to support and underpin the design of marine pro- Possingham, 2003; Lombard, Cowling, Pressey, & tected areas. Rebelo, 2003; Roberts et al., 2003; Williams et al., Using acoustic technologies such as multibeam 2008; Williams & Bax, 2001). Biodiversity conservation echosounder and side scan sonar (SSS), very high-res- is a major objective for MPAs globally. It is necessary to olution data with total coverage of the seabed are know the composition and distribution of benthic acquired. The resulting bathymetric data and the geo- communities, the characteristics of a natural and morphological characteristics of the seabed, derived healthy state, and the effects of different human activi- from their acoustic properties, represent an excellent ties (e.g. EC, 2008b; epbrs, 2013; Steltzenmüller et al., base for the geomorphological and geological fi 2013). classi cations of the seabed (Buhl-Mortensen, CONTACT Giacomo Deiana [email protected] © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 2 G. DEIANA ET AL. Buhl-Mortensen, Dolan, & Holte, 2015). These phys- articulation of the seabed which is highlighted by the ical classifications of the seabed in turn form an essen- differential erosion. tial component in benthic habitat mapping that The main river valleys reflect the characteristics of a integrates biological properties and has been widely paleo – hydrographic with tectonic control, which is used (Brown, Smith, Lawton, & Anderson, 2011 and connected to the coastal rias (De Muro & Ulzega, references therein). Marine habitat mapping has been 1985); depressions with an parallel elongation axis to defined as ‘Plotting the distribution and extent of habi- the coast, interpretable as paleo – lagoons connected tats to create a map with complete coverage of the to the late Pleistocene sea levels are also recognized seabed showing distinct boundaries separating adjacent (Ulzega, Lecca, & Leone, 1981). habitats’ (MESH, 2008). The Quaternary deposits such as the fossil conglom- In 1992, the first geomorphological map (Orrù & erates detected in the Spalmatore Peninsula (Tavolara Pasquini, 1992) and the first biocenotic map of seabed Island) and attributed to the last interglacial locally in the MPA has been created. Subsequently, previous known as Tyrrhenian (Ulzega & Ozer, 1982), rest on morphological knowledge has been investigated with the Jurassic transgressive succession, which is rep- the acquisition of new multibeam and side scan sonar resented by calcareous conglomerates and dolomitic data acquired full coverage under an agreement limestone up to bioclastic limestones. between MPA and Agence de L’eau Andromede Ocea- nologie (France). A new geomorphological map has 3. Methods been created in the MPA in which the distribution of incoherent sediments, rocky outcrops and the main Geophysical survey methods were used to derive data morphologies has been mapped; this document about the geomorphology and lithology of the seabed, implements the knowledge bases about the seabeds which was acquired by side scan sonar (SSS) and multi- habitats mapping. beam echosounders (MBES). These instruments acquired data on the seabed’sreflectivity (SSS), bathy- metric data at a high resolution (MBES) and a combi- 2. Geological setting nation of the two. Acoustic reflectivity (acoustic The seabed of the Marine Protected Area Tavolara is backscatter) is a complex function of many factors: dominated by the crystalline basement associated the acoustic frequency, the angle of incidence, the with the Hercynian emplacement of the Corsica-Sar- slope of the seabed, the roughness scale, the particle dinia batholiths and is comprised of granites, rose size distribution, the presence of fauna and flora on monzogranite and biotite leucogranite (Ghezzo & the bottom, and bioturbation. This process goes Orsini, 1982). The dyke system has a mainly acidic under the name of segmentation and is more com- composition with quartz porphyry (Andreolli et al., monly known as the acoustic classification of the 1971). seabed (Acoustic Seabed Classification ASC, Anderson, The Mesozoic is formed by dolomite and limestone, Holliday, Kloser, Reid, & Simard, 2008; Brown & Blon- at the base it is characterized by Middle Jurassic silici- del, 2009). As part of the morphometric analysis, quan- clastic to carbonate successions of the Genna Selole titative information derived from bathymetry such as Formation with