Blue whale behavioral ecology

This collection contains data used in a study of the movement ecology of blue whales in the eastern North Pacific, off central California, USA.  The study was published in Ecology Letters in 2022 and is entitled, “Oceanic giants dance to atmospheric rhythms: Ephemeral wind-driven resource tracking by blue whales.”  As of this writing, the article does not yet have a DOI.  Data include:

1) Acoustic vector sensor (AVS) tracking of blue whale calls

Annual periods of blue whale acoustic presence were analyzed across two years to examine the directional distribution of call origin around the MARS cabled observatory.  Quality controlled data include the time, bearing, and call index of all manually validated seconds for which the blue whale B-call index exceeded a value of 1.25.  These data appear in Figures 4 and 5 of the paper.  The files are AVS_2019-2020.RData and AVS_2020-2021.RData.

2) Modeled received levels at the MARS cabled observatory

The geographic domain over which received signal is sufficient to reliably estimate the direction of blue whale B-call origin from the MARS cabled observatory was approximated by modeling of acoustic transmission loss.  These data appear in Figure 2C of the paper.  Model results represent received level (underwater dB) at the MARS cabled observatory, assuming appropriately specified intensity, depth, and frequency of the sound source and oceanographic physical conditions during the time of year when blue whale calling is most active.  The file is ModeledReceivedLevel.RData.

3) Animal-borne tag data

Data from a biologging tag deployed on a blue whale were used to validate an acoustic vector sensor on the MARS cabled observatory.  These data appear in Figure 3 of the paper and include information about whale behaviors (diving, calling, lunge feeding) and surface position from GPS.  In addition to identified behavioral events, underlying hydrophone and accelerometer data used to identify behaviors during the period of matchup with AVS data are included.  The file is Tag_bw191101-70.RData.  

4) Forage species aggregation data

The area scattering (sa) within patches in the upper 200 m above the MARS cabled observatory, presented in Figure 5E of the paper, are in the file MARS_sa.RData.

本数据集收录了用于美国加利福尼亚州中部外海东太平洋海域蓝鲸运动生态学研究的相关数据。该研究于2022年发表于《Ecology Letters》（生态学通讯），论文标题为《大洋巨物随大气节律起舞：蓝鲸短暂追踪风驱资源的行为》。截至本说明撰写时，该论文尚未获取数字对象标识符（DOI）。数据集包含以下内容：

1) 声学矢量传感器（Acoustic Vector Sensor, AVS）蓝鲸叫声追踪
本研究对两年间的蓝鲸声学出现年度周期展开分析，以探究MARS海底有线观测站（MARS cabled observatory）周边蓝鲸叫声源的方位分布特征。经过质量控制的数据包含所有经人工校验的秒级数据的时间、方位角与叫声指数，其中蓝鲸B型叫声指数需大于1.25。该数据对应论文中的图4与图5，相关数据文件为AVS_2019-2020.RData与AVS_2020-2021.RData。

2) MARS海底有线观测站的模拟接收声级
本部分通过声学传播损失建模，近似得到可通过MARS海底有线观测站可靠估算蓝鲸B型叫声源方位的信号接收地理范围。该数据对应论文中的图2C，模型结果以水下分贝（dB）为单位表示MARS海底有线观测站处的接收声级，假设声源强度、深度与频率均已合理设定，且匹配蓝鲸最活跃的鸣叫时段的海洋物理环境条件。相关数据文件为ModeledReceivedLevel.RData。

3) 动物搭载式生物记录标签数据
本部分使用部署于蓝鲸身上的生物记录标签数据，对MARS海底有线观测站搭载的声学矢量传感器进行校验。该数据对应论文中的图3，包含蓝鲸行为（潜水、鸣叫、滤食冲刺）信息以及基于GPS获取的海面位置数据。除已识别的行为事件外，还包含用于匹配AVS数据时段内行为识别的原始水听器与加速度计数据。相关数据文件为Tag_bw191101-70.RData。

4) 猎食物种聚集数据
本部分收录了MARS海底有线观测站上方200米水层内斑块区域的面积散射系数（sa）数据，对应论文中的图5E，相关数据文件为MARS_sa.RData。