Scientists follow hatchlings from Cape Verde with tiny acoustic transmitters
With new nano-sized acoustic transmitters, scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel, the Turtle Foundation and Queen Mary University of London were able to follow the pathways of loggerhead turtle hatchlings from Cape Verde.
The tiny animals quickly swim through predator-rich coastal waters and are then dispersed by nearby ocean currents. According to the study, which was primarily funded by the Kiel Cluster of Excellence “The Future Ocean”, the local oceanic conditions are believed to drive the evolution of some unique swimming behaviours. The results are published in the current issue of the Proceedings of the Royal Society B.
Loggerhead turtles (Caretta caretta) from Cape Verde start their lives with a swimming sprint and a ride on favourable ocean currents. In this way, they escape quickly from predator-rich coastal areas and make their way to the safer open ocean where they spend several years feeding and growing. In this study, tiny acoustic transmitters provided direct insight into these pathways for the first time.
“Thanks to the new technology we can start to fill in key information gaps about the so-called ‘lost years’ Dr. Rebecca Scott states. Funded by the Kiel Cluster of Excellence “The Future Ocean”, the marine biologist coordinated a joint study of GEOMAR Helmholtz Centre for Ocean Research Kiel, the Turtle Foundation and the School of Biological and Chemical Sciences and Dr. Christophe Eizaguirre at the Queen Mary University of London.
“Scientists call this early life phase the ‘lost years’, because they were not able to follow new-born sea turtle hatchlings very far. Hatchlings essentially disappear into the sea until many years later when the lucky survivors return to where they born to breed. But with new techniques like nano-tags and ocean models we are able to see where the tiny young animals go. This is important because the dispersal experiences of hatchlings drive the development of their behaviours into adulthood. The more we understand about the biological and physical determinants of their dispersal and swimming behaviours, the easier we can protect this endangered species.”
In cooperation with the Turtle Foundation at Boa Vista, Cape Verde, the scientists collected hatchlings from two beaches in the northwest and southern tip of the island. Acoustic transmitters with a five millimetres wide and twelve millimetres long streamlined shape that weigh 0,4 grams in water were glued onto the shell of eleven hatchlings. The turtles were then followed at sea using a boat and acoustic receiver for up to eight hours and 15 kilometres. In addition, the swimming behaviour of 16 hatchlings were monitored in “hatchling swimming pools” for several days using data loggers made by engineers at GEOMAR. The turtles swam continuously during their first 24 hours after hatching and then switched to a pattern of activity at daytime and inactivity at night.
Due to the close proximity of offshore currents in this region, it seems the Cape Verdean hatchlings can sleep more at night than hatchlings from other places. For example in America, different research groups have shown that they would have swim a lot more to reach offshore currents”, Dr. Scott explains. “Deep oceanic water and favourable currents, which then determined the travel directions and speeds of our Cape Verdean turtles are situated very near to their nests. Therefore, it is very beneficial for turtles if local oceanic conditions drive the evolution of swimming behaviours that are unique to different nesting locations to ensure their best survival outcomes. It seems that turtles are born with these unique locally adapted behaviours.”
Finally, because larger animals kept swimming for a longer time than smaller individuals, a larger body size is thought to be a good sign of fitness. “But there is some evidence emerging that higher nest temperatures may reduce the size of hatchlings. Therefore, it might be possible that global warming decreases the fitness of the sea turtles by threatening them in more subtle ways than just obvious dangers like the loss of nesting beaches”, Dr. Scott assumes.
Scott, R., Biastoch, A., Roder, C., Stiebens, V. A. and Eizaguirre, C., 2014: Nano-tags for neonates and ocean-mediated swimming behaviours linked to rapid dispersal of hatchling sea turtles. Proc. R. Soc. B., 218, 20141209, doi:10.1098/rspb.2014.1209
Cluster of Excellence “The Future Ocean”
The School of Biological and Chemical Sciences at the Queen Mary University of London
Rebecca Scott (GEOMAR, FB3-EV), Tel.: +49 431 600-4569, firstname.lastname@example.org
Maike Nicolai (GEOMAR Communication & Media) Tel.: +49 431 600-2807, email@example.com
Maike Nicolai | Eurek Alert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences