Giant Devil Rays in the North-Western Mediterranean Sea


Description :

 Original provider:
Giuseppe Notarbartolo di Sciara, Tethys Research Institute

Dataset credits:
Tethys Research Institute

Abstract:
The giant devil ray Mobula mobular, the only Mediterranean mobulid, is subject to mortality caused by directed and accidental captures in fisheries throughout the region. Whilst the combination of human impacts, limited range and a low reproductive potential is not inconsistent with its endangered listing, there are insufficient data to enable a quantitative assessment of trends. Without this, it is difficult to assess and prioritise threats and develop effective conservation actions. Using results from aerial surveys conducted between 2009 and 2014 over the Ligurian, Corsican, Sardinian, northern and central Tyrrhenian seas (626,228 km2), this study provides the first quantitative information on giant devil ray abundance and habitat choice in the western Mediterranean. Devil rays were observed in all seasons except winter, with their estimated abundance in the study area peaking in summer.
The overall uncorrected mean density in the study area during summer was estimated at 0.0257 individuals km-2 (range: 0.017–0.044), resulting in a total abundance estimate of 6,092 (12.7%CV) individuals at the surface; once corrected for availability bias, this estimate indicates a summer presence of >12,700 devil rays in the study area. Rays were mostly observed alone even if occasionally, larger aggregations up to a maximum of 18 individuals were observed. Although observed throughout the study area, spatial modelling identified their preferred habitat to be over a broad strip connecting the Tuscan Archipelago to Eastern Sardinia, over a wide range of water depths ranging from 10 to 2000m. The observed seasonal changes in giant devil ray distribution in this study, combined with similar evidence from other areas in the Mediterranean, support the hypothesis that the species
undertakes latitudinal migrations across the region, taking advantage of highly productive waters in the north during summer, and warmer southern waters during winter.

Supplemental information:
Some records do not have time part.

Link GBIF portal : https://www.gbif.org/dataset/c9b33318-2033-4f94-afcf-e88ba2ddb272

Project :
Title : Giant Devil Rays in the North-Western Mediterranean Sea
Abstract : 
Funding : NA
Contact : Notarbartolo di Sciara Giuseppe (OWNER) 

Key words

 No information 

Field

continental
marine

Protocole

 No information 

Geographic extent

Contacts

Type Organization Name
Fournisseur Tethys Research Institute NOTARBARTOLO DI SCIARA Giuseppe
Producteur Tethys Research Institute NOTARBARTOLO DI SCIARA Giuseppe
Fournisseur PATRINAT (OFB-MNHN-CNRS-IRD)

Publication dates :

First diffusion : 14/03/2023 
Last update : 30/11/2023  

Species list found :

Filter by Kingdom

Filter by Class

Filter by Order

Filter by Family
Scientific name CD_NOM Kingdom Class Order Family Date of first observation Date of last observation Sheet

Chiffres clés :

 44 données 
 1 espèces 
 1 taxons 

Répartition des données par groupes taxonomiques :

Groupes vernaculaires de premier ordre
Groupes vernaculaires de second ordre

Répartition temporelle: