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（Biologging）技术正在革新海洋环境的观测与监测范式。然而，获取其采集的高分辨率数据通常需要回收搭载设备，因此该技术的应用范围往往局限于可预测返回陆地的动物。数据提取与传输技术旨在破解这一局限，但目前此类技术的应用场景有限，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. 本研究提出一种全新方法，可通过阿尔戈斯（Argos）卫星系统，从自由活动的海洋捕食者身上采集、提取并传输加速度计数据。我们针对该技术开展了试运行：实验对象为来自凯尔盖朗群岛的20头幼年南象海豹（Mirounga leonina），采样时段覆盖其断奶后出海的最初数月。通过回收其中9头返回繁殖群的个体的存档数据，我们将提取传输得到的数据与已成熟的加速度计处理流程的输出结果进行对比与验证。 3. 提取传输的数据包含潜水剖面五个分段的相关估算值，涵盖猎物捕获尝试（PrCA）行为耗时、游泳能耗与俯仰角。随后我们将这些数据按三个潜水阶段——下潜、水底停留、上浮——进行汇总，并与存档数据的输出结果展开对比。两组数据集间的相关性存在差异，但整体表现良好（依潜水阶段而定，边际决定系数R²介于0.45至0.6至>0.9之间），且个体间结果一致性较高。传输得到的PrCA行为与游泳能耗估算值，相较于存档处理结果存在正向偏差。 4. 本研究的数据代表了首批来自加速度计的远程传输量化成果之一。本文提出并分析的方法，可为探索难以回收记录器的自由活动海洋捕食者（如幼年南象海豹）的行为与运动模式提供全新视角。不过未来的应用可通过部分调整加以优化，尤其需要降低传输得到的PrCA行为与游泳能耗估算值的正向偏差，本研究为此提供了极具价值的参考思路。