Contrasted habitats and individual plasticity drive the fine scale movements of juvenile green turtles in coastal ecosystems
|Author(s)||Chambault Philippine1, Dalleau Mayeul2, Nicet Jean-Benoit3, Mouquet Pascal4, Ballorain Katia2, 5, Jean Claire6, Ciccione Stéphane6, Bourjea Jerome1|
|Affiliation(s)||1 : UMR MARBEC, IFREMER, CNRS, IRD, University of Montpellier, Avenue Jean Monnet, 34200, Sète, France
2 : Centre d’Etude et de Découverte des Tortues Marines (CEDTM), 6 chemin Dubuisson, Appt. 5, 97436, Saint-Leu, La Réunion, France
3 : GIE MAREX, 697 Chemin Surprise, La Fontaine, 97436, Saint Leu, La Réunion, France
4 : Université de La Réunion/UMR ESPACE-DEV, Antenne SEAS-OI, 40 Avenue de Soweto, 97410, Saint-Pierre, La Réunion, France
5 : Biodiversity French Agency, Mayotte and Glorieuses Marine Nature Parks, 6 chemin Dubuisson, Appt. 5, 97436, Saint-Leu, La Réunion, France
6 : Kelonia, l’observatoire des tortues marines, 46 rue du Général de Gaulle, 97436, Saint Leu, La Réunion, France
|Source||Movement Ecology (2051-3933) (Springer), 2020-01 , Vol. 8 , N. 1 , P. 15p.|
|Keyword(s)||Chelonia mydas, Home range, Satellite tracking, Diel pattern, Tidal cycle|
A strong behavioural plasticity is commonly evidenced in the movements of marine megafauna species, and it might be related to an adaptation to local conditions of the habitat. One way to investigate such behavioural plasticity is to satellite track a large number of individuals from contrasting foraging grounds, but despite recent advances in satellite telemetry techniques, such studies are still very limited in sea turtles.
From 2010 to 2018, 49 juvenile green turtles were satellite tracked from five contrasting feeding grounds located in the South-West Indian Ocean in order to (1) assess the diel patterns in their movements, (2) investigate the inter-individual and inter-site variability, and (3) explore the drivers of their daily movements using both static (habitat type and bathymetry) and dynamic variables (daily and tidal cycles).
Despite similarities observed in four feeding grounds (a diel pattern with a decreased distance to shore and smaller home ranges at night), contrasted habitats (e.g. mangrove, reef flat, fore-reef, terrace) associated with different resources (coral, seagrass, algae) were used in each island.
Juvenile green turtles in the South-West Indian Ocean show different responses to contrasting environmental conditions - both natural (habitat type and tidal cycle) and anthropogenic (urbanised vs. uninhabited island) demonstrating the ability to adapt to modification of habitat.