Long-term changes in adult size of green turtles at Aldabra Atoll and implications for clutch size, sexual dimorphism and growth rates

Abstract Around the world, declines in mean size of nesting sea turtles have been reported with concerns a concomitant decrease reproductive output populations. Here, we explore this possibility using long-term observations green ( Chelonia mydas ) at Aldabra Atoll, Seychelles. Based on > 4500 individual measurements over 21 years (1996–2016), found curved carapace length females declined by about 0.64 cm per decade, from 111.43 to 110.08 cm. For 391 individuals that were measured more than once measurement interval 2.8–19 apart, growth rate was 0.14 year ?1 . Comparisons between adult and males based 23 14 weight measurements, 107 33 103 width respectively, taken during 1981–1983. Adult larger males, sexual dimorphism index, i.e. ratio sex smaller, being 1.09 1.10 for width, 1.25 weight. Smaller tended lay fewer eggs clutch but female accompanied increases numbers annually, such estimated total increased 1.3 million 2.0 1996 2016. Therefore, has not compromised egg production population.