Growth rates and age at adult size of loggerhead sea turtles (Caretta caretta) in the Mediterranean Sea, estimated through capture-mark-recapture records
Growth rates of the juvenile phase of loggerhead turtles (Caretta caretta) were estimated for the first time in the Mediterranean Sea from capture-mark-recapture records. Thirty-eight turtles were released from Italian coasts and re-encountered after 1.0-10.9 years in the period 1986-2007. Their mea...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Consejo Superior de Investigaciones Científicas
2009-09-01
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| Series: | Scientia Marina |
| Subjects: | |
| Online Access: | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1088 |
| Summary: | Growth rates of the juvenile phase of loggerhead turtles (Caretta caretta) were estimated for the first time in the Mediterranean Sea from capture-mark-recapture records. Thirty-eight turtles were released from Italian coasts and re-encountered after 1.0-10.9 years in the period 1986-2007. Their mean CCL (curved carapace length) ranged from 32.5 to 82.0 cm and they showed variable growth rates, ranging from 0 to 5.97 cm/yr (mean: 2.5). The association between annual growth rate and three covariates (mean year, mean size and time interval) was investigated through a non-parametric modelling approach. Only mean size showed a clear effect on growth rate, described by a monotonic declining curve. Variability indicates that factors not included in the model, probably individual-related ones, have an important effect on growth rates. Based on the monotonic decreasing growth function which indicates no growth spurt, a von Bertalanffy growth function was used to estimate the time required by turtles to grow within the observed size range. The results indicate that turtles would take 16-28 years to reach 66.5-84.7 cm CCL, the average nesting female sizes observed at the most important Mediterranean nesting sites, which can be considered an approximation of the size at maturity. |
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| ISSN: | 0214-8358 1886-8134 |