Department of Life Sciences, Roehampton University, London, United Kingdom.
PLoS One. 2011;6(8):e22311. doi: 10.1371/journal.pone.0022311. Epub 2011 Aug 4.
Measuring the metabolic of sea turtles is fundamental to understanding their ecology yet the presently available methods are limited. Accelerometry is a relatively new technique for estimating metabolic rate that has shown promise with a number of species but its utility with air-breathing divers is not yet established. The present study undertakes laboratory experiments to investigate whether rate of oxygen uptake (VO2) at the surface in active sub-adult green turtles Chelonia mydas and hatchling loggerhead turtles Caretta caretta correlates with overall dynamic body acceleration (ODBA), a derivative of acceleration used as a proxy for metabolic rate. Six green turtles (25-44 kg) and two loggerhead turtles (20 g) were instrumented with tri-axial acceleration logging devices and placed singly into a respirometry chamber. The green turtles were able to submerge freely within a 1.5 m deep tank and the loggerhead turtles were tethered in water 16 cm deep so that they swam at the surface. A significant prediction equation for mean VO2 over an hour in a green turtle from measures of ODBA and mean flipper length (R(2) = 0.56) returned a mean estimate error across turtles of 8.0%. The range of temperatures used in the green turtle experiments (22-30 °C) had only a small effect on Vo₂. A VO2-ODBA equation for the loggerhead hatchling data was also significant (R(2) = 0.67). Together these data indicate the potential of the accelerometry technique for estimating energy expenditure in sea turtles, which may have important applications in sea turtle diving ecology, and also in conservation such as assessing turtle survival times when trapped underwater in fishing nets.
测量海龟的新陈代谢对于了解其生态学至关重要，但目前可用的方法有限。加速度计是一种相对较新的技术，可用于估算代谢率，该技术已在许多物种中显示出前景，但尚未确定其在呼吸空气潜水者中的应用。本研究进行了实验室实验，以研究主动亚成体绿海龟 Chelonia mydas 和幼体红海龟 Caretta caretta 在水面上的耗氧量 (VO2) 是否与总体动态身体加速度 (ODBA) 相关，ODBA 是加速度的一个衍生指标，可作为代谢率的替代指标。将六只绿海龟（25-44 公斤）和两只红海龟（20 克）用三轴加速度记录设备进行了仪器化，并单独放入呼吸室中。绿海龟可以在 1.5 米深的水箱中自由潜水，红海龟被拴在 16 厘米深的水中，以便在水面上游泳。ODBA 和平均鳍长测量值对绿海龟一小时内平均 VO2 的显著预测方程（R²=0.56），跨海龟的平均估计误差为 8.0%。在绿海龟实验中使用的温度范围（22-30°C）对 Vo₂ 的影响很小。针对 loggerhead 幼龟数据的 VO2-ODBA 方程也具有显著意义（R²=0.67）。这些数据表明，加速度计技术在估算海龟能量消耗方面具有潜力，这可能在海龟潜水生态学以及保护方面具有重要应用，例如评估海龟在渔网上被困在水下时的生存时间。
