Navigation Links
Isotope analysis reveals foraging area dichotomy for Atlantic leatherback turtles
Date:3/25/2008

The beaches of French Guiana constitute a major reproduction site for leatherback turtles. This sea turtle, although a protected species, is threatened by human activity: it ingests plastics, get accidentally caught in fishing nets, sees its egg-laying sites destroyed and its adults hunted illegally for their meat and their eggs. Female turtles return to the same beach every two to three years to lay their eggs. What happens in the interval remains a mystery. It is sometimes possible to spot them offshore in the North Atlantic. Some even swim to very high latitudes (Canada) in search of their favorite food (principally jellyfish). Argos beacons have recently revealed that some females were swimming in two principal directions: the north as would be expected, but also towards the African coast east of French Guiana.

The question is whether these locations represent two distinct feeding areas or simply an extra stopover in their migration to the far north.

Several French and Belgian scientists (University of Paris-Sud and the Laboratory for Oceanology of the University of Lige, respectively) have studied the question, in particular the carbon and nitrogen isotope ratios (d13C and d15N) in the blood and eggs of these turtles. Isotope ratios are indeed significant dietary markers and indicate, if conditions are favorable, the diet of the animals in recent days, weeks or months, depending on the tissue analyzed.

These analyses, published in this weeks PLoS ONE, are the culmination of long and painstaking fieldwork carried out by the team from the University of Paris-Sud in Guiana. Researchers worked around the clock spotting the turtles, identifying them thanks to their tags (electronic chips serving to identify the animals), and taking blood and egg samples. Some of the sampled females had laid their eggs on the same beach two years previously, others three.

Analysis of the samples showed that the carbon and nitrogen isotrope ratios were different for each group, which suggests that the turtles had had a different diet before laying their eggs. These isotope ratios (especially the carbon ratios) are indicative of a dichotomy in the feeding areas of the two groups: one fed in the high latitudes of the North Atlantic's pelagic zone, the other in the low latitudes of the North Atlantic off the African and Iberian coasts. The existence of these two distinct feeding areas remains to be confirmed over the long run (through the observation of sea turtles), but these preliminary results already show how urgent it is to determine the precise geographical feeding areas used by the leatherback turtles as well as the duration of their visit during the interval between egg-layings.

The fact that leatherback turtles use two distinct feeding areas over a long period has major implications as far as their preservation is concerned. If one of these two habitats were to be damaged because of overfishing, pollution, sea traffic, etc, this could have dramatic repercussions on the survival of the species.


'/>"/>

Contact: Didier Moreau
dmoreau@ulg.ac.be
Public Library of Science
Source:Eurekalert

Related biology news :

1. Ginkgo SRMs: Tools for product analysis/quality
2. DNA analysis shows true dispersal of protozoa
3. Interacting protein theory awaits test from new neutron analysis tools
4. Analysis of breast and colon cancer genes finds many areas of differences between tumors
5. Tumor genome analysis unveils new insights into lung cancer
6. Powerful integration of lipid metabolic profiling with gene expression analysis
7. Human clones: New U.N. analysis lays out worlds choices
8. More comprehensive analysis of Klamath River basin needed to aid decision makers
9. Analysis calls for medical device information to better serve patients and doctors
10. Avian origins: new analysis confirms ancient beginnings
11. DOE JGI releases a new version of its metagenome data management and analysis system
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/18/2016)... Jan. 18, 2016  Extenua Inc., a pioneering ... the use and access of ubiquitous on-premise and ... with American Cyber.  ... leading transformational C4ISR and Cyber initiatives in support ... latest proven technology solutions," said Steve Visconti ...
(Date:1/13/2016)... , January 13, 2016 ... published a new market report titled - Biometric Sensors Market ... Forecast, 2015 - 2023. According to the report, the global biometric ... is anticipated to reach US$1,625.8 mn by 2023, expanding ... In terms of volume, the biometric sensors market is ...
(Date:1/11/2016)... , Jan. 11, 2016 Synaptics Incorporated ... interface solutions, today announced that its ClearPad ® ... (TDDI) products won two separate categories in the 8 ... Innovator and Best Technology Breakthrough. The Synaptics ® ... a simplified supply chain, thinner devices, brighter displays and ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... 11, 2016  Vermillion, Inc. (NASDAQ: VRML ), ... announced the formation of the Steering Committee for its ... --> Pelvic masses can present physicians and ... Once pregnancy is ruled out, pelvic masses may include ... endometriosis, benign ovarian tumors and gastrointestinal and urinary tract ...
(Date:2/11/2016)... , Feb. 11, 2016  Spectra BioPharma Selling ... (CSO) that provides biopharma companies the experience, expertise, ... and deploy outsourced sales teams. Created in concert ... addresses both the strategic and tactical needs of ... sales solutions through both personal and non-personal promotion. ...
(Date:2/11/2016)... Feb. 11, 2016  Dovetail Genomics™ LLC today announced ... program for a planned metagenomic genome assembly service. ... metagenomic genome assembly method in a talk on Friday, ... & Technology conference in Orlando, Fla. ... complex datasets is difficult. Using its proprietary ...
(Date:2/11/2016)... ... February 11, 2016 , ... Reichert Technologies, which has created ... pursue the highest level of accuracy and quality with the addition of two ... AR5 Refractometer. Accurate, reliable and tough enough for the most demanding applications, ...
Breaking Biology Technology: