Tethys Research Institute

Milano, Italy

Tethys Research Institute

Milano, Italy
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Adnet S.,Montpellier University | Cappetta H.,Montpellier University | Guinot G.,Montpellier University | Di Sciara G.N.,Tethys Research Institute
Zoological Journal of the Linnean Society | Year: 2012

The exact affinities of the fossil teeth attributed to the devilrays (mobulids) are critical for resolving the debated origin of these giant pelagic rays amongst Myliobatiformes and the timing of their evolution toward planktivory. We performed the rst detailed comparative description of teeth belonging to most of the living and fossil mobulids. Based on a survey of living devilrays, three dental morphologies are newly identied as cobblestone tooth plates, comb-like teeth, and peg-like teeth. In addition, all extinct mobulid species are reviewed with comments on their dentition, fossil record, and geographical distribution. As a result, three fossil mobulid taxa are newly described from the Late Eocene of south-west Morocco (Argoubia barbei gen. et sp. nov., Oromobula dakhlaensis gen. et sp. nov., and Eoplinthicus underwoodi sp. nov.). This has permitted the rst assessment of the phylogenetic positions of extinct and extant species of mobulids, using cladistic analyses and a combined data set of nondental anatomical characters from the literature and the dental characters dened here. Our new results support the monophyly of mobulids including all living and most extinct species and indicate that mobulids are closely related to rhinopterids. They also indicate that there was a recent split within Mobulidae into the three tooth morphology groups that we describe in this paper. This work provides clues to the evolutionary history of this clade since the Early Eocene, including the gradual lack in tooth interlocking toward the lter-feeding strategy, whereas the preservation of cusped teeth without feeding function in modern lter-feeder mobulids is interpreted as a tool for precopulatory purposes. © 2012.

Bearzi G.,Tethys Research Institute | Bonizzoni S.,Tethys Research Institute | Gonzalvo J.,Tethys Research Institute
Journal of Ethology | Year: 2011

While bottlenose dolphins in Mediterranean waters often display a high degree of site fidelity, movements across distant areas can occur. Such movements have important implications in terms of population viability, particularly in basins with low bottlenose dolphin densities. We report movements of nine individuals photo-identified up to 265 km apart in western Greece. Four showed a certain degree of site fidelity to one area across several years, but were also found elsewhere, with two individuals moving between two areas. This study provides further evidence that animals appearing to be "resident" within a given area can temporarily leave and range widely. © 2010 Japan Ethological Society and Springer.

Agardy T.,Sound Seas | di Sciara G.N.,Tethys Research Institute | Christie P.,University of Washington
Marine Policy | Year: 2011

A blind faith in the ability of MPAs to counteract loss of biodiversity is fraught with risk, especially when MPAs are poorly planned and when the consequences of establishing MPAs are not adequately thought out. MPA shortcomings are categorized as one of five main types: (1) MPAs that by virtue of their small size or poor design are ecologically insufficient; (2) inappropriately planned or managed MPAs; (3) MPAs that fail due to the degradation of the unprotected surrounding ecosystems; (4) MPAs that do more harm than good due to displacement and unintended consequences of management; and (5) MPAs that create a dangerous illusion of protection when in fact no protection is occurring. A strategic alternative, which fully utilizes the strengths of the MPA tool while avoiding the pitfalls, can overcome these shortcomings: integrating marine protected area planning in broader marine spatial planning and ocean zoning efforts. © 2010 Elsevier Ltd.

Bearzi G.,Tethys Research Institute | Bonizzoni S.,Tethys Research Institute | Gonzalvo J.,Tethys Research Institute
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2011

Dolphins are often blamed for reducing fisheries catches and may be killed in retaliation. Depredation of fishing gear in coastal Mediterranean waters is normally caused by bottlenose dolphins. Economic impact, however, may be modest even within areas of reportedly acute conflict. Boat surveys and interviews were conducted to investigate dolphin occurrence and interactions with fisheries within the 167km2 Porto Cesareo Marine Protected Area (MPA) in southern Italy. Based on 69 interviews with fishermen using bottom-set trammel and gill nets, there was reportedly a high occurrence of depredation by bottlenose dolphins. Depredation was reported by 92% of the fishermen operating in or near the MPA, and 67% of them claimed an economic cost in excess of €1000 per year, with a mean reported cost of €2561: a higher impact than in other Mediterranean studies. According to local fishermen, dolphin occurrence and depredation peaked in spring and autumn, coincident with the study's surveys at sea. Dedicated visual surveys totalling 1255km of effort, however, resulted in no encounters with cetaceans. Information from interviews and boat surveys was therefore contradictory, suggesting that reports of acute depredation do not imply a constant presence of dolphins within the MPA. While depredation in the MPA might be caused by wide-ranging dolphins or incursions occurring overnight, damage may well be overestimated or over-reported. As local fishermen had previously benefited from subsidies, interviews made during this study could be perceived by some as an opportunity to influence future decision-making regarding monetary compensation for the impact of depredation. 5. Evidence from interviews also indicated that species and factors other than dolphins were responsible for part of the damage. © 2011 John Wiley & Sons, Ltd.

Portman M.E.,Technion - Israel Institute of Technology | Notarbartolo-di-Sciara G.,Tethys Research Institute | Agardy T.,Sound Seas | Katsanevakis S.,European Commission - Joint Research Center Ispra | And 2 more authors.
Marine Policy | Year: 2013

Although significant advancements on protecting marine biodiversity and ecosystems of the Mediterranean Sea have been made, much remains to be done to achieve the targets set by the Convention for Biological Diversity (and the Barcelona Convention) and ratified by the 21 Mediterranean governments. Particularly, these targets require the design and implementation of an ecologically representative network of marine protected areas that covers 10% of the Mediterranean surface by 2020. Despite the many efforts to gather spatial information about threats to the Mediterranean and conservation planning initiatives that identify sensitive areas for conservation, we are far from achieving this target. In this paper, we briefly review existing and proposed conservation initiatives at various scales throughout the Mediterranean to recognise those that have political endorsement and those that serve more as lobbying tools. We then propose a model process that can be applied to advance marine spatial planning within the eleven ecologically and biologically significant areas (EBSAs) through a multi-step process designed for moving conservation forward in this particularly complex region. The proposed process combines tenets of professional urban/regional planning and systematic conservation planning. As shown with two specific examples, despite some conventional wisdom, there is enough information on the Mediterranean Sea to move forward with ecosystem-based marine spatial management for conservation purposes using the EBSAs as a starting point - and the time is right to do so. © 2013 Elsevier Ltd.

Guidetti P.,University of Nice Sophia Antipolis | Notarbartolo-Di-Sciara G.,Tethys Research Institute | Agardy T.,Sound Seas
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2013

Marine Protected Areas (MPAs) have gained increasing popularity worldwide as tools for biodiversity conservation and management of human uses. This rise in popularity has been accompanied by an increasing body of scientific papers and books on MPA design and management, the vast majority of which are almost completely focused on coastal or insular MPAs. A small number of MPAs have also been established in the pelagic domain, however, these pelagic sites have been considered in isolation from coastal/insular MPAs, even when the sites are adjacent or nearby. Pelagic and coastal ecosystems are not at all isolated from each other, but interconnected both physically via the flow of water, and biologically, via the movement of organisms. In order to maximize the effectiveness of MPAs, it is suggested that spatial management planning encompass large areas that span both coastal and pelagic domains. This requires integrated, large-scale spatial management, which may extend across borders and thus require international cooperation. © 2012 John Wiley & Sons, Ltd.

Piroddi C.,University of British Columbia | Piroddi C.,Tethys Research Institute | Giovanni B.,Tethys Research Institute | Villy C.,University of British Columbia
Ecological Modelling | Year: 2010

To better understand the effects of fisheries and ocean productivity on the northeastern Ionian Sea we constructed an Ecopath with Ecosim model with 22 functional groups. Data on biomass, production/biomass, consumption/biomass, and diet for each group were estimated or extrapolated from the literature. Fisheries landings and discards were also included. Temporal trajectories were simulated using Ecosim. The model was fitted with time-series data for the most important groups from 1964 to 2006. Simulations highlighted a decline of top predators and of most of the commercial species since the late 1970s. The model shows that the decline of fish resources was mainly caused by an intensive fishing pressure that occurred in the area until the end of the 1990s and also by changes in primary production that impacted the trajectories of the main functional groups. In particular, simulated changes through time in PP impacted the abundance trends of all the commercial species, showing a cascade-up effect through the ecosystem. The application of Ecopath with Ecosim was a useful tool for understanding the trends of the main functional groups of the northeastern Ionian Sea. The model underlined that management actions are needed to restore and protect target species including marine mammals, pelagic and demersal fishes. In particular, measures to reduce overfishing, illegal fishing activities and to respect existing legislations are in need. Moreover, the adoption of marine protected areas could be an effective management measure to guarantee prey survival and to sustain marine predators. © 2010 Elsevier B.V. All rights reserved.

Piroddi C.,University of British Columbia | Piroddi C.,Tethys Research Institute | Bearzi G.,Tethys Research Institute | Gonzalvo J.,Tethys Research Institute | Christensen V.,University of British Columbia
Biological Conservation | Year: 2011

Although overfishing has been recognized as responsible for the decline of major fish stocks, it has been less easy to demonstrate its indirect and detrimental effects on marine mammals, particularly dolphins. Competition with fisheries for the same food resources has been hypothesized to have led to the decline of several species of dolphins, including the endangered Mediterranean short-beaked common dolphin. Based on an ecosystem model for the Inner Ionian Sea Archipelago, a former hotspot for common dolphins in the Mediterranean Sea, we investigated the effect of increasing fishing effort on common dolphins, its prey and on marine biodiversity and we evaluated the outcomes of different fisheries closures (1 - closure of the purse seine fishery, 2 - closure of purse seine, trawl and beach seine fisheries, 3 - entire area closed to fisheries) ran between the years 2011 and 2030. Our results showed that local fisheries have negatively impacted the marine biodiversity of the ecosystem causing sharp declines of common dolphins and major fish stocks and weakening the robustness of the marine food web. The implementation of fisheries closures would gradually recover fish stocks, while common dolphins would increase more pronouncedly only if the study area was to be closed to all fisheries. As shown in this study, common dolphins have reflected ecosystem changes and degradation over time. Ensuring the survival of dolphin populations is thereby essential to enhance marine ecosystems and ensure sustainable fishing. © 2011 Elsevier Ltd.

Frantzis A.,Pelagos Cetacean Research Institute | Airoldi S.,Tethys Research Institute | Notarbartolo-di-Sciara G.,Tethys Research Institute | Johnson C.,Earthocean | Mazzariol S.,University of Padua
Deep-Sea Research Part I: Oceanographic Research Papers | Year: 2011

The sperm whale is one of the very few deep diving mammal species in the Mediterranean Sea. Following a rare mass stranding of male sperm whales in the Adriatic Sea in December 2009, photo-identification methods were used in order to investigate previous sightings of the stranded whales in the region. Fluke photos of the stranded whales were compared with those of 153 and 128 free-ranging individuals photographed in the western and eastern Mediterranean basins, respectively. Three out of the seven stranded whales had been previously photo-identified and some of them more than once. To reach the stranding place, two of these re-identified whales performed long-range inter-basin movements of about 1600-2100. km (in a straight line) either through the Strait of Sicily or the Strait of Messina. In addition, comparisons among all whales photographed in the two Mediterranean basins revealed that one more individual first photographed in the western basin (1991) was re-identified 13 years later in the eastern basin (2004). These three cases provide the first conclusive evidence of inter-basin movement of sperm whales in the Mediterranean Sea. Inter-basin gene flow is important for the survival of the small and endangered Mediterranean sperm whale population. Mitigating the disturbance created by human activities in the straits area is crucial for its conservation. © 2011 Elsevier Ltd.

Notarbartolo-Di-Sciara G.,Tethys Research Institute
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2014

Sperm whales in the Mediterranean are a genetically distinct population classified as Endangered on the basis of the IUCN Red List criteria. Threats that result in sperm whale direct mortality, such as bycatch in illegal driftnets and collisions with ships, together with the noxious effects of noise, pollution, ingestion of solid debris, disturbance from irresponsible whale watching operations, and possibly prey depletion and climate change, affect the survival of the Mediterranean population and are the cause of an inferred continuing decline. Recommendations to sustain the presence of sperm whales in the Mediterranean in the future include respecting existing fishery, pollution and whale watching regulations, and introducing precautionary noise and maritime traffic regulations in areas characterized by high sperm whale densities, some of which could be considered for MPA designation. Finally, the regular monitoring of sperm whale population ecology, behaviour and mortality at the regional scale, to detect trends and help to understand links between the observed phenomena and their possible cause(s), could help to address other potential threats, such as prey depletion and climate change. © 2013 John Wiley & Sons, Ltd.

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