Avens Larisa, Goshe Lisa R, Coggins Lewis, Shaver Donna J, Higgins Ben, Landry Andre M, Bailey Rhonda
National Marine Fisheries Service, Southeast Fisheries Science Center, NOAA Beaufort Laboratory, Beaufort, North Carolina, United States of America.
US Fish and Wildlife Service, Yukon Delta National Wildlife Refuge, Bethel, Alaska, United States of America.
PLoS One. 2017 Mar 23;12(3):e0173999. doi: 10.1371/journal.pone.0173999. eCollection 2017.
Effective management of protected sea turtle populations requires knowledge not only of mean values for demographic and life-history parameters, but also temporal and spatial trends, variability, and underlying causes. For endangered Kemp's ridley sea turtles (Lepidochelys kempii), the need for baseline information of this type has been emphasized during attempts to understand causes underlying the recent truncation in the recovery trajectory for nesting females. To provide insight into variability in age and size at sexual maturation (ASM and SSM) and long-term growth patterns likely to influence population trends, we conducted skeletochronological analysis of humerus bones from 333 Kemp's ridleys stranded throughout the Gulf of Mexico (GOM) from 1993 to 2010. Ranges of possible ASMs (6.8 to 21.8 yr) and SSMs (53.3 to 68.3 cm straightline carapace length (SCL)) estimated using the "rapprochement" skeletal growth mark associated with maturation were broad, supporting incorporation of a maturation schedule in Kemp's ridley population models. Mean ASMs estimated from rapprochement and by fitting logistic, generalized additive mixed, and von Bertalanffy growth models to age and growth data ranged from 11 to 13 yr; confidence intervals for the logistic model predicted maturation of 95% of the population between 11.9 and 14.8 yr. Early juvenile somatic growth rates in the GOM were greater than those previously reported for the Atlantic, indicating potential for differences in maturation trajectories between regions. Finally, long-term, significant decreases in somatic growth response were found for both juveniles and adults, which could influence recruitment to the reproductive population and observed nesting population trends.
有效管理受保护的海龟种群不仅需要了解种群统计学和生活史参数的平均值，还需要了解其时间和空间趋势、变异性以及潜在原因。对于濒危的肯普氏丽龟（Lepidochelys kempii），在试图了解导致筑巢雌龟近期恢复轨迹中断的潜在原因时，强调了此类基线信息的必要性。为了深入了解性成熟时的年龄和大小变异性（ASM和SSM）以及可能影响种群趋势的长期生长模式，我们对1993年至2010年期间在墨西哥湾（GOM）搁浅的333只肯普氏丽龟的肱骨进行了骨骼年代学分析。使用与成熟相关的“和解”骨骼生长标记估计的可能ASM范围（6.8至21.8年）和SSM范围（直线背甲长度（SCL）为53.3至68.3厘米）很广，这支持在肯普氏丽龟种群模型中纳入成熟时间表。通过和解以及将逻辑斯蒂、广义相加混合和冯·贝塔朗菲生长模型拟合到年龄和生长数据估算的平均ASM范围为11至13年；逻辑斯蒂模型的置信区间预测95%的种群在11.9至14.8年之间成熟。墨西哥湾早期幼体的体细胞生长率高于此前在大西洋报道的生长率，这表明不同区域的成熟轨迹可能存在差异。最后，发现幼体和成体的体细胞生长反应均出现长期显著下降，这可能会影响繁殖种群的补充以及观察到的筑巢种群趋势。
