Profile
I have been studying sea turtles in the Chagos Archipelago since 2012, working closely with Professor Graeme Hays and Dr Jeanne Mortimer.
During 2012-2021, we satellite tracked 36 post-nesting green turtles (Chelonia mydas) using Fastloc – GPS telemetry and recorded a huge range in migrations, from 75 km within the MPA surrounding the Chagos Archipelago to >5000 km to distant foraging grounds on the east coast of Africa, including Mozambique, Kenya and Somalia. Our current work includes use of satellite telemetry and other technologies such as drones and loggers to increase our understanding of key nesting and foraging grounds for immature and adult stages of both green turtles and the critically endangered hawksbill turtle (Eretmochelys imbricata) in the Western Indian Ocean. We are also conducting long-term monitoring of sea turtle nesting and foraging populations in the Chagos Archipelago, including long-term records of sand temperature to assess likely sea turtle hatchling sex ratios and hatching success.
Our satellite tracking research in the Chagos Archipelago has led to incredible discoveries of extensive seagrass meadows on the Great Chagos Bank at unexpected depths of 25-30 metres – providing critical habitats for juvenile fish populations and foraging green turtles.
Biography
My Project
Other interests
Currently investigating the effects of macro- and microplastics on sea turtle incubation conditions using a range of field and controlled laboratory conditions. This research is funded by DEFRA Darwin Plus project (2019-2022): Reducing the impacts of plastic on the Chagos Archipelago natural environment.
My Publications
Travel routes to remote ocean targets reveal the map sense resolution for a marine migrant
Hays, G.C., Atchison-Balmond, N., Cerritelli, G., Laloë, J.O., Luschi, P., Mortimer, J.A., Rattray, A., and Esteban, N., (2022) Travel routes to remote ocean targets reveal the map sense resolution for a marine migrant. Journal of the Royal Society Interface
A Global Review of Green Turtle Diet: Sea Surface Temperature as a Potential Driver of Omnivory Levels
Esteban, N., Mortimer, J.A., Stokes, H.J. et al. A global review of green turtle diet: sea surface temperature as a potential driver of omnivory levels. Mar Biol 167, 183 (2020). https://doi.org/10.1007/s00227-020-03786-8
Open Ocean Reorientation and Challenges of Island Finding by Sea Turtles During Long-Distance Migration
Hays, G.C., Cerritelli, G., Esteban, N., Rattary, A. and Luschi, P. (2020) Open ocean reorientation and challenges of island finding by sea turtles during long-distance migration. Current Biology.
A Review of a Decade of Lessons From One of the World’s Largest MPAs: Conservation Gains and Key Challenges
Hays, G.C., Koldewey, H.J., Andrzejaczek, S., Attrill, M.J., Barley, S., Bayley, D.T.I., Benkwitt, C.E., Block, B., Schallert, R.J., Carlisle, A., Carr, P., Chapple, T.K., Collins, C., Diaz, C., Dunn, N., Dunbar, R.B., Eager, D.S., Engel, J., Embling, C.B., Esteban, N., Ferretti, F., Foster, N.L., Freeman, R., Gollock, M., Graham, N.A.J., Harris, J.L., Head, C.E.I, Hosegood, P., Howell, K.L., Hussey, N.E., Jacoby, D.M.P., Jones, R., Pilly, J.S., Lange, I.D., Letessier, T.B., Levy, E., Lindhart, M., McDevitt-Irwin, J.M., Meekan, M., Meeuwig, J.J., Micheli, F., Mogg, A., Mortimer, J.A., Mucciarone, D.A., Nicoll, M.A., Nuno, A., Perry, C., Preston, S.G., Rattray, A.J., Robinson, E., Roche, R., Schiele, M., Sheehan, E.V., Sheppard, A., Sheppard, C., Smith, A.L., Soule, B., Spalding, M., Stevens, G.M.W., Steyaert, M., Stiffel, S., Taylor, B.M., Tickler, D., Trevail, A.M., Trueba, P., Turner, J., Votier, S., Wilson, B., Williams, G., Williamson, B., Williamson, M.J., Wood, H. and Curnick, D.J. (2020) A review of a decade of lessons from one of the world’s largest MPAs: conservation gains and key challenges. Marine Biology.
Addressing Tagging Location Bias to Assess Space Use by Marine Animals
Hays, G.C., Rattray, A. and Esteban, N. (2020) Addressing tagging location bias to assess space use by marine animals. Journal of Applied Ecology.
