Wallace Bryan P, Williams Cassondra L, Paladino Frank V, Morreale Stephen J, Lindstrom R Todd, Spotila James R
Drexel University, Department of Bioscience and Biotechnology, 3141 Chestnut Street, Philadelphia, PA 19104 USA.
J Exp Biol. 2005 Oct;208(Pt 20):3873-84. doi: 10.1242/jeb.01860.
Physiology, environment and life history demands interact to influence marine turtle bioenergetics and activity. However, metabolism and diving behavior of free-swimming marine turtles have not been measured simultaneously. Using doubly labeled water, we obtained the first field metabolic rates (FMRs; 0.20-0.74 W kg(-1)) and water fluxes (16-30% TBW day(-1), where TBW=total body water) for free-ranging marine turtles and combined these data with dive information from electronic archival tags to investigate the bioenergetics and diving activity of reproductive adult female leatherback turtles Dermochelys coriacea. Mean dive durations (7.8+/-2.4 min (+/-1 s.d.), bottom times (2.7+/-0.8 min), and percentage of time spent in water temperatures (Tw) < or =24 degrees C (9.5+/-5.7%) increased with increasing mean maximum dive depths (22.6+/-7.1 m; all P< or =0.001). The FMRs increased with longer mean dive durations, bottom times and surface intervals and increased time spent in Tw< or =24 degrees C (all r2> or =0.99). This suggests that low FMRs and activity levels, combined with shuttling between different water temperatures, could allow leatherbacks to avoid overheating while in warm tropical waters. Additionally, internesting leatherback dive durations were consistently shorter than aerobic dive limits calculated from our FMRs (11.7-44.3 min). Our results indicate that internesting female leatherbacks maintained low FMRs and activity levels, thereby spending relatively little energy while active at sea. Future studies should incorporate data on metabolic rate, dive patterns, water temperatures, and body temperatures to develop further the relationship between physiological and life history demands and marine turtle bioenergetics and activity.
生理学、环境和生活史需求相互作用，影响着海龟的生物能量学和活动。然而，自由游动的海龟的代谢和潜水行为尚未同时被测量。我们使用双标水，首次获得了自由放养海龟的野外代谢率（FMRs；0.20 - 0.74 W kg⁻¹）和水通量（16 - 30% 总体水/天，其中总体水 = 全身水），并将这些数据与电子存档标签的潜水信息相结合，以研究成年雌性棱皮龟（Dermochelys coriacea）繁殖期的生物能量学和潜水活动。平均潜水持续时间（7.8 ± 2.4分钟（±1标准差））、底栖时间（2.7 ± 0.8分钟）以及在水温（Tw）≤24℃的水中停留时间的百分比（9.5 ± 5.7%）随着平均最大潜水深度的增加而增加（22.6 ± 7.1米；所有P≤0.001）。FMRs随着平均潜水持续时间、底栖时间和水面间隔的延长以及在Tw≤24℃的水中停留时间的增加而增加（所有r²≥0.99）。这表明低FMRs和活动水平，再加上在不同水温之间穿梭，可能使棱皮龟在温暖的热带水域中避免过热。此外，在筑巢间期棱皮龟的潜水持续时间始终短于根据我们的FMRs计算出的有氧潜水极限（11.7 - 44.3分钟）。我们的结果表明，筑巢间期的雌性棱皮龟维持低FMRs和活动水平，因此在海上活动时消耗的能量相对较少。未来的研究应纳入代谢率、潜水模式、水温及体温的数据，以进一步阐明生理需求和生活史需求与海龟生物能量学和活动之间的关系。
