A University of Exeter team has monitored the movements of an entire sub-population of marine turtle for the first time. The study tracked 68 adult female turtles between 1998 and 2008, one of the largest sample sizes to date, for 372.2 ± 210.4 days.Although satellite tracking has yielded much information regarding the migrations and habitat use of threatened marine species, relatively little
has been previously published about the environmental niche for loggerhead sea turtles Caretta caretta in north-west Atlantic waters. The study confirms that through satellite tracking the day-to-day lives in migration and habitat usage of marine species can be monitored and used to accurately predict their migrations and help direct conservation efforts.
Writing in the journal Diversity and Distributions, lead author and University of Exeter PhD student Dr Lucy Hawkes (now at Bangor University) describes the migrations of a population of loggerhead turtles in the US Atlantic Ocean over a decade (1998-2008). The findings reveal that, despite travelling thousands of miles every year, they rarely leave the waters of the USA or the continental shelf. This discovery could help the US direct conservation efforts where it is needed most.The loggerhead sea turtle is a wide-ranging species, occurring
throughout the temperate sub-tropical and tropical regions of the Atlantic, Pacific, and Indian Oceans. In the Atlantic, the loggerhead turtle's range extends from Newfoundland to as far south as Argentina. This study focused on monitoring adult females that nest 
along the coast from North Carolina to Georgia each summer and showed that they forage in shallow warm waters off most of the United States eastern seaboard. The study also revealed that the turtles which travel as far north to forage as New Jersey have to head south to avoid the cold winter there.The study's conclusion stated: "Findings show that
adult female loggerhead turtles display predictable, repeatable home range behavior and do not generally leave waters of the USA, nor the continental shelf. These data offer insights for future marine management, particularly if they were combined with those from the other management units in the USA."Dr Lucy Hawkes (left) said: "This is the first time, to
our knowledge, that anyone has been able to say precisely where and when you would find an entire sub-population of marine turtles. This is incredibly useful for conservation as it tells us exactly where to put our efforts. We knew that satellite tracking was a valuable tool, but this study highlights how powerful it is -- without it we would still be guessing where these beautiful but vulnerable creatures live."Dr Brendan Godley (right) who led the University of
Exeter team has been using satellite tracking to monitor sea turtles since 1997. He said: "By attaching small satellite tracking devices to turtles' shells, we can accurately monitor their whereabouts. Working with biologists and conservation groups around the world we are starting to build a much clearer picture of the lives of marine turtles, including their migrations, breeding and feeding habits. These findings form a valuable resource for conservation groups, who are concerned with protecting turtles from threats posed by fishing, pollution and climate change."Source:
University of Exeter. "Marine turtle movements tracked." ScienceDaily, 23 Jun. 2011. Web. 27 Jun. 2011.
Original Journal Source:
Lucy A. Hawkes, Matthew J. Witt, Annette C. Broderick, John W. Coker, Michael S. Coyne, Mark Dodd, Michael G. Frick, Matthew H. Godfrey, DuBose B. Griffin, Sally R. Murphy, Thomas M. Murphy, Kris L. Williams, Brendan J. Godley. Home on the range: spatial ecology of loggerhead turtles in Atlantic waters of the USA. Diversity and Distributions, 2011; 17 (4): 624 DOI: 10.1111/j.1472-4642.2011.00768.x
