Marine turtle sightings, strandings and captures in French waters 1990-2003
Matthew Witt, University of Exeter

Dataset credit

Matthew Witt, University of Exeter

Contacts

RoleNameOrganization 
Primary contact Matthew Witt University of Exeter
Data entry Connie Kot Duke University

Citation

Abstract

We present data spanning approximately 100 years regarding the spatial and temporal occurrence of marine turtle sightings and strandings in the
northeast Atlantic from two public recording schemes and demonstrate potential signals of changing population status. Records of loggerhead (n = 317) and Kemp’s ridley (n = 44) turtles occurring on the European
continental shelf were most prevalent during the autumn and winter, when waters were coolest. In contrast, endothermic leatherback turtles (n = 1,668) were most common during the summer. Analysis of the spatial distribution of hard-shell marine turtle sightings and strandings highlights a pattern of decreasing records with increasing latitude. The spatial distribution
of sighting and stranding records indicates that arrival in waters of the European continental shelf is most likely driven by North Atlantic current systems. Future patterns of spatial-temporal distribution, gathered
from the periphery of juvenile marine turtles habitat range, may allow for a broader assessment of the future impacts of global climate change on species
range and population size.

Purpose

We set out to determine the spatial and temporal trends for sightings, strandings and captures of hard-shell marine turtles in the northeast Atlantic from two recording schemes. One recording scheme (presented here) included marine turtle sightings, strandings and captures occurring in French waters that originated from annual sightings and strandings publications of Duguy and colleagues (Duguy 1990, 1992, 1993, 1994, 1995, 1996, 2004; Duguy et al. 1997a, b, 1999, 2000, 2001, 2002, 2003). Records presented in Duguy publications prior to 2001 contained location descriptions, providing no geographic coordinates with error estimates. Longitude and latitude positions for these events were estimated to be the closest coastal point to the descriptive location.


Duguy publications, 2001 onwards, were accompanied by maps displaying the approximate location of sightings and strandings events. These maps were digitized and georeferenced and coordinate positions determined for all appropriate records. Georefenced hard-shell turtle (Lk and Cc) capture/sighting/stranding records from the papers of Duguy for France 1990-2003 (featured in Witt et al. 2007) only includes records that could have coordinates derived from their locational descriptions.


The second recording scheme used were records of sightings and strandings of marine turtles in the British Isles obtained from the TURTLE database operated by Marine Environmental Monitoring. Data from the TURTLE database were submitted to EurOBIS and can be viewed on OBIS-SEAMAP: Marine Turtles.

Supplemental information

Abstract is from Witt et al. 2007; data included in this dataset are a subset of data presented in Witt et al. 2007.

References:

Duguy, R. 1990. Observations de tortues marines en 1990 (Manche et Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 7:1053–1057.

Duguy, R. 1992. Observations de tortues marines en 1991 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:35–37.

Duguy, R. 1993. Observations de tortues marines en 1992 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:129–131.

Duguy, R. 1994. Observations de tortues marines en 1993 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:235–238.

Duguy, R. 1995. Observations de tortues marines en 1994 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:403–406.

Duguy, R. 1996. Observations de tortues marines en 1995 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:505–513.

Duguy, R. 2004. Observations de tortues marines en 2003 (cotes Atlantiques). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 9:361–366.

Duguy, R., P. Moriniere and A. Meunier. 1997a. Observations de tortues marines en 1997. Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:761–779.

Duguy, R., P. Moriniere and M.A. Spano. 1997b. Observations de tortues marines en 1996 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:625–632.

Duguy, R., P. Moriniere and A. Meunier. 1999. Observations de tortues marines en 1998 (Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime:911–924.

Duguy, R., P. Moriniere and A. Meunier. 2000. Observations de tortues marines en 1999. Annales de la Societe des Sciences Naturelles de la Charente-Maritime 8:1025–1034.

Duguy R, P. Moriniere and A. Meunier. 2001. Observations tortues marines en 2000 (Atlantique et Manche). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 9:17–25.

Duguy, R., P. Moriniere and A. Meunier. 2002. Observations de tortues marines en 2001 (Atlantique et Manche). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 9.

Duguy, R., P. Moriniere and A. Meunier. 2003. Observations de tortues marines en 2002 (Atlantique et Manche). Annales de la Societe des Sciences Naturelles de la Charente-Maritime 9:265–273.

References

Witt, M.J., R. Penrose and B.J. Godley. 2007. Spatio-temporal patterns of juvenile marine turtle occurrence in waters of the European continental shelf. Marine Biology. 151:873-885.
Duguy, R. 1990. Observations de tortues marines en 1990 (Manche et Atlantique). Annales de la Societe des Sciences Naturelles de la Charente-Maritime. 7:1053–1057.
Duguy, R. 2004. Observations de tortues marines en 2003 (cotes Atlantiques). Annales de la Societe des Sciences Naturelles de la Charente-Maritime. 9:361–366.

Attributes

Overview

Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downlodable online. Other attributes may be obtained upon provider's permission unless otherwise noted below.

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes in dataset provided

Attribute (table column)Description
oidUnique ID (generated by OBIS-SEAMAP)
sp_obsSpecies observed
sp_tsnSpecies ITIS TSN
statusendefinition not provided
statusfrdefinition not provided
sightstrandefinition not provided
dayDay of observation
monthMonth of observation
yearYear of observation
obs_dateDate of observation
latitudeLatitude of observation
longitudeLongitude of observation
locationDescription of location
sclStraight carapace length (cm)
massMass (kg)
obs_timeTime was not available so "00:00:00" was used
obs_countCount was not available, so 1 was used
notesNotes on when time and count was not available, so "00:00:00" and 1 were used, respectively
geomdefinition not provided
OBIS-SEAMAP ID877
Seabirds0
Marine mammals0
Sea turtles199
Rays and sharks0
Other species0
Non spatial0
Non species0
Total199
Date, Begin1990-01-08
Date, End2003-08-10
Temporal prec.111000
Latitude43.39 - 51.05
Longitude-4.83 - 2.37
Coord. prec.6 decimal digits
PlatformShore
Data typeAnimal sighting
EffortN/A
Registered2012-10-08
Updated2012-10-15
StatusPublished
Sharing policy CC-BY-NC (Minimum)
Also availalbe from iOBIS
See metadata in static HTML
See metadata in FGDC XML
See download history / statistics
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