Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela

Endangered Species Research
By: , and 

Links

Abstract

Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela
Series title Endangered Species Research
DOI 10.3354/esr00695
Volume 29
Issue 2
Year Published 2015
Language English
Publisher Inter-Research
Contributing office(s) Coop Res Unit Seattle
Description 14 p.
First page 103
Last page 116
Country Venezuela
Other Geospatial Aves Island
Online Only (Y/N) N
Additional Online Files (Y/N) N