Abstract
The Risso’s dolphin is a widely distributed species, found in deep temperate and tropical waters. Estimates of its abundance are available in a few regions, details of its distribution are lacking, and its status in the Mediterranean Sea is ranked as Data Deficient by the IUCN Red List. In this paper, a synergy between bio-ecological analysis and innovative strategies has been applied to construct a digital platform, DolFin. It contains a collection of sighting data and geo-referred photos of Grampus griseus, acquired from 2013 to 2016 in the Gulf of Taranto (Northern Ionian Sea, North-eastern Central Mediterranean Sea), and the first automated tool for Smart Photo Identification of the Risso’s dolphin (SPIR). This approach provides the capability to collect and analyse significant amounts of data acquired over wide areas and extended periods of time. This effort establishes the baseline for future large-scale studies, essential to providing further information on the distribution of G. griseus. Our data and analysis results corroborate the hypothesis of a resident Risso’s dolphin population in the Gulf of Taranto, showing site fidelity in a relatively restricted area characterized by a steep slope to around 800 m in depth, north of the Taranto Valley canyon system.
Highlights
The Risso’s dolphin Grampus griseus (Cuvier, 1812)[1] is a small Odontocetes distributed from the tropics throughout the temperate regions in both hemispheres[1,2,3,4,5], living in the deep waters of the continental slope and outer shelf, especially those areas with a steep bottom topography[6,7,8,9,10,11]
We present a novel investigation, which aims to improve the knowledge of the Risso’s dolphin in the Gulf of Taranto (Northern Ionian Sea, North-eastern Central Mediterranean Sea), by defining its spatial distribution and site fidelity, based on a synergy between bio-ecological information on the species and innovative technological strategies
The results show that when σs increases Smart Photo Identification of the Risso’s dolphin (SPIR)’s accuracy increases up to 94% evaluated on the best quality images, having sharpness higher than 21.93
Summary
The Risso’s dolphin Grampus griseus (Cuvier, 1812)[1] is a small Odontocetes distributed from the tropics throughout the temperate regions in both hemispheres[1,2,3,4,5], living in the deep waters of the continental slope and outer shelf, especially those areas with a steep bottom topography[6,7,8,9,10,11] Despite it being considered a regular inhabitant of the Mediterranean Sea[12,13,14], the Risso’s dolphin remains one of the least-known cetacean species in the basin, with its status is ranked as Data Deficient by the IUCN Red List[15]. Several existing catalogues containing dolphin photos taken around the world are, available (i.e. Dolphin Dock, http://www.dolphindock.com.au/; Morigenos Slovenian Marine Mammal Society, http://www.morigenos.org/en/morigenos/; Associaciò Cetàcea, http://www.associaciocetacea.org/) They include little information about Risso’s dolphin sightings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
