Body condition changes at sea: Onboard calculation and telemetry of body density in diving animals
Body condition changes at sea: Onboard calculation and telemetry of body density in diving animals
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DOI：
10.1111/2041-210x.14089
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发表时间：
2023-04-04
影响因子：
6.6
通讯作者：
Miller，Patrick J. O.
中科院分区：
文献类型：
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作者：
Adachi，Taiki;Lovell，Philip;Miller，Patrick J. O.
海洋哺乳动物积累足够的脂质能量储备的能力对哺乳动物的生存和成功繁殖至关重要。然而，长期监测身体状况的海上变化，特别是脂质储存，只有在进行长时间漂流潜水的海象中才有可能（低密度脂质改变了漂流时的深度变化率）。这种方法对其他物种的适用性有限。利用过境滑行期间的流体动力学性能分析，我们开发并验证了一种新型卫星连接数据记录器，可以计算身体密度的真实的实时变化（‡脂质储存）。由于滑翔在潜水员中无处不在，该系统可以评估各种潜水动物的身体状况。该标签处理高采样率深度和三轴加速度数据，以识别深度> 100 m处的5 s高俯仰角下滑段。身体密度估计为每个滑翔使用滑翔速度和间距，以量化阻力与浮力作用于滑翔动物。以验证相对于漂移率的机身密度的机载计算。新的标签中继身体密度估计超过200天，并记录了迁移过程中的脂质储存积累与身体密度和漂移率之间的变化有很好的对应关系。我们的研究提供了更新的阻力系数值的滑翔（镉，f = 0.03）和漂流（镉，s = 0.12）的海象，都大大低于以前的估计。我们还证明了使用传输数据对滑翔阻力系数和物体密度的事后估计，这是特别有用的阻力参数时，不能估计足够的精度前标签部署。我们的方法有可能推进海洋生物学领域的研究范式从间接推断动物身体状况的觅食努力，以直接测量身体状况的变化相对于觅食努力，生境，生态因素和人为压力在不断变化的海洋。将该方法扩展到考虑潜水空气量将扩大系统对浅潜水（<100 m）物种的适用性，促进对各种屏气潜水员的身体状况进行真实的实时监测。
The ability of marine mammals to accumulate sufficient lipid energy reserves is vital for mammals' survival and successful reproduction. However, long‐term monitoring of at‐sea changes in body condition, specifically lipid stores, has only been possible in elephant seals performing prolonged drift dives (low‐density lipids alter the rates of depth change while drifting). This approach has limited applicability to other species.Using hydrodynamic performance analysis during transit glides, we developed and validated a novel satellite‐linked data logger that calculates real‐time changes in body density (∝lipid stores). As gliding is ubiquitous amongst divers, the system can assess body condition in a broad array of diving animals. The tag processes high sampling rate depth and three‐axis acceleration data to identify 5 s high pitch angle glide segments at depths >100 m. Body density is estimated for each glide using gliding speed and pitch to quantify drag versus buoyancy forces acting on the gliding animal.We used tag data from 24 elephant seals (Miroungaspp.) to validate the onboard calculation of body density relative to drift rate. The new tags relayed body density estimates over 200 days and documented lipid store accumulation during migration with good correspondence between changes in body density and drift rate. Our study provided updated drag coefficient values for gliding (Cd,f= 0.03) and drifting (Cd,s= 0.12) elephant seals, both substantially lower than previous estimates. We also demonstrated post‐hoc estimation of the gliding drag coefficient and body density using transmitted data, which is especially useful when drag parameters cannot be estimated with sufficient accuracy before tag deployment.Our method has the potential to advance the field of marine biology by switching the research paradigm from indirectly inferring animal body condition from foraging effort to directly measuring changes in body condition relative to foraging effort, habitat, ecological factors and anthropogenic stressors in the changing oceans. Expanding the method to account for diving air volumes will expand the system's applicability to shallower‐diving (<100 m) species, facilitating real‐time monitoring of body condition in a broad range of breath‐hold divers.