High rates of growth recorded for hawksbill sea turtles in Anegada, British Virgin Islands.
Management of species of conservation concern requires knowledge of demographic parameters, such as rates of recruitment, survival, and growth. In the Caribbean, hawksbill turtles (Eretmochelys imbricata) have been historically exploited in huge numbers to satisfy trade in their shells and meat. In the present study, we estimated growth rate of juvenile hawksbill turtles around Anegada, British Virgin Islands, using capture-mark-recapture of 59 turtles over periods of up to 649 days. Turtles were recaptured up to six times, having moved up to 5.9 km from the release location. Across all sizes, turtles grew at an average rate of 9.3 cm year(-1) (range 2.3-20.3 cm year(-1)), and gained mass at an average of 3.9 kg year(-1) (range 850 g-16.1 kg year(-1)). Carapace length was a significant predictor of growth rate and mass gain, but there was no relationship between either variable and sea surface temperature. These are among the fastest rates of growth reported for this species, with seven turtles growing at a rate that would increase their body size by more than half per year (51-69% increase in body length). This study also demonstrates the importance of shallow water reef systems for the developmental habitat for juvenile hawksbill turtles. Although growth rates for posthatching turtles in the pelagic, and turtles larger than 61 cm, are not known for this population, the implications of this study are that Caribbean hawksbill turtles in some areas may reach body sizes suggesting sexual maturity in less time than previously considered.
Centre for Ecology & Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus Penryn, TR10 9EZ, U.K.
Lucy A
LA
Hawkes
Centre for Ecology & Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus Penryn, TR10 9EZ, U.K.
Andrew
A
McGowan
Centre for Ecology & Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus Penryn, TR10 9EZ, U.K.
Annette C
AC
Broderick
Conservation and Fisheries Department, Ministry of Natural Resources and Labour PO Box 3323, Road Town, Tortola, British Virgin Islands.
Shannon
S
Gore
The Settlement Anegada, British Virgin Islands.
Damon
D
Wheatley
The Settlement Anegada, British Virgin Islands.
Jim
J
White
Environment and Sustainability Institute, University of Exeter, Penryn Campus Penryn, Cornwall, TR10 9EZ, U.K.
Matthew J
MJ
Witt
Centre for Ecology & Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus Penryn, TR10 9EZ, U.K.
Brendan J
BJ
Godley
Caribbean; conservation; growth rates; hawksbill turtle; sex ratio; sexual maturity