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.
Data Records
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 298 records.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
Versions
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Notarbartolo di Sciara, G. 2016. Giant Devil Rays in the North-Western Mediterranean Sea. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/1370) on yyyy-mm-dd.
Rights
Researchers should respect the following rights statement:
The publisher and rights holder of this work is OBIS-SEAMAP. This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC 4.0) License.
GBIF Registration
This resource has been registered with GBIF, and assigned the following GBIF UUID: c9b33318-2033-4f94-afcf-e88ba2ddb272. OBIS-SEAMAP publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.
Keywords
Occurrence,Marine Animal Survey,Marine Biology,Visual Sighting,Aircraft; Observation; Occurrence
External data
The resource data is also available in other formats
| OBIS-SEAMAP Dataset Page | http://seamap.env.duke.edu/dataset/1370 UTF-8 Interactive map |
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| FGDC Metadata | http://seamap.env.duke.edu/dataset/1370/xml UTF-8 XML |
Contacts
- Owner ●
- Originator ●
- Point Of Contact
- Metadata Provider ●
- Distributor
Geographic Coverage
Mediterranean Sea
| Bounding Coordinates | South West [36.266, 5.854], North East [44.301, 19.001] |
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Taxonomic Coverage
Scientific names are based on the Integrated Taxonomic Information System (ITIS).
| Species | Mobula mobular (giant devil ray) |
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Temporal Coverage
| Start Date / End Date | 2009-07-21 / 2013-08-07 |
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Project Data
No Description available
| Title | Giant Devil Rays in the North-Western Mediterranean Sea |
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| Funding | NA |
The personnel involved in the project:
- Owner
Sampling Methods
NA
| Study Extent | NA |
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Method step description:
- NA
Collection Data
| Collection Name | zd_1370 |
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| Collection Identifier | zd_1370 |
| Parent Collection Identifier | OBIS-SEAMAP |
Additional Metadata
marine, harvested by iOBIS
| Purpose | Not available |
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| Alternative Identifiers | http://ipt.env.duke.edu/resource?r=zd_1370 |