Data from: Processing of acceleration and dive data on-board satellite relay tags to investigate diving and foraging behaviour in free-ranging marine predators

1. Biologging technologies are changing the way in which the marine environment is observed and monitored. However, because device retrieval is generally required to access the high resolution data they collect, use is generally restricted to those animals that predictably return to land. Data abstraction and transmission techniques aim to address this, although currently these are limited in scope and do not incorporate, for example, acceleration measurements which can quantify animal behaviours and movement patterns over fine-scales. 2. In this study, we present a new method for the collection, abstraction and transmission of accelerometer data from free-ranging marine predators via the Argos satellite system. We test run the technique on 20 juvenile southern elephant seals Mirounga leonina from the Kerguelen Islands during their first months at sea following weaning. Using retrieved archival data from nine individuals that returned to the colony, we compare and validate abstracted transmissions against outputs from established accelerometer processing procedures. 3. Abstracted transmissions included estimates, across five segments of a dive profile, of time spent in prey catch attempt (PrCA) behaviours, swimming effort and pitch. These were then summarised and compared to archival outputs across three dive phases: descent, bottom and ascent. Correlations between the two datasets were variable but generally good (dependent on dive phase, marginal R2 values of between 0.45 and 0.6 to > 0.9) and consistent between individuals. Transmitted estimates of PrCA behaviours and swimming effort were positively biased to those from archival processing. 4. Data from this study represents some of the first remotely transmitted quantifications from accelerometers. The methods presented and analysed can be used to provide novel insight toward the behaviours and movements of free-ranging marine predators, such as juvenile southern elephant seals, from whom logger retrieval is challenging. Future applications could however benefit from some adaption, particularly to reduce positive bias in transmitted PrCA behaviours and swimming effort, for which this study provides useful insight.

1. 生物记录技术正革新海洋环境的观测与监测范式。然而，由于获取其采集的高分辨率数据通常需要回收记录设备，该技术的应用范围往往局限于那些可预测返回陆地的动物。数据提取与传输技术旨在解决这一痛点，但当前此类技术的应用场景受限，例如无法纳入可精细化量化动物行为与运动模式的加速度测量数据。
2. 本研究提出了一种全新方法，可通过阿尔戈斯卫星系统（Argos satellite system）对自由活动的海洋捕食者的加速度计（accelerometer）数据进行采集、提取与传输。研究团队于凯尔盖朗群岛的20只断奶后首月出海的南象海豹幼崽（*Mirounga leonina*）身上开展了该技术的试运行。通过回收其中9只返回繁殖群的个体的存档数据，我们将提取传输的数据与已成熟的加速度计处理流程输出结果进行对比与验证。
3. 提取传输的数据涵盖了潜水剖面五个分段内的捕食尝试（Prey Catch Attempt，PrCA）行为时长、游泳功耗与俯仰角估算值。随后研究人员将这些数据按下潜、底栖、上升三个潜水阶段进行汇总，并与存档输出结果进行对比。两组数据集的相关性存在波动，但整体表现良好（依潜水阶段不同，边际决定系数（marginal R²）介于0.45至0.6，最高可达0.9以上），且个体间结果一致性较强。传输得到的PrCA行为与游泳功耗估算值相较于存档处理结果均存在正向偏差。
4. 本研究的数据是首批通过远程传输获取的加速度计量化数据之一。本研究提出并验证的方法，可为记录设备回收难度较高的自由活动海洋捕食者（如南象海豹幼崽）的行为与运动模式研究提供全新视角。不过未来的应用可通过适当调整进行优化，尤其是针对降低传输得到的PrCA行为与游泳功耗估算值的正向偏差问题，本研究为此提供了具有参考价值的思路。