Moon jellyfish aggregations observed by a scientific echo sounder and an underwater video camera and their relation to internal waves
Moon jellyfish aggregations observed by a scientific echo sounder and an underwater video camera and their relation to internal waves
复制标题
通过科学回声测深仪和水下摄像机观察到的月水母聚集及其与内波的关系
DOI：
10.1007/s10872-019-00507-8
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发表时间：
2019
影响因子：
2.3
通讯作者：
Saito Rui
中科院分区：
文献类型：
--
作者：
Mano Takashi;Guo Xinyu;Fujii Naoki;Yoshie Naoki;Tsutsumi Eisuke;Saito Rui
我们发现，在日本小海湾（保口津湾和三龟湾），科学回声测深仪测得的平均体积后向散射强度与水下摄像机同时记录的月水母分布密度之间存在良好的线性关系。这种关系在近年来（2013-2016）进行的所有调查中都成立，尽管由于环境生物的存在，回归系数每年略有不同。利用这种关系和高分辨率回声测深仪扫描整个海湾，我们获得了月水母聚集体的空间结构，并将它们分类为斑片状、层状或波浪状聚集体。我们还研究了月水母聚集的可能物理机制。特别是，对几个理想化内波场的被动粒子跟踪模拟表明，波状聚集体的形成与内波的存在密切相关。然而，内波本身不能引起斑片状和分层的聚集，这表明特定的生物过程（例如游泳行为）对于这种聚集的形成也是必要的。
We found a good linear relation between the mean volume backscattering strength measured using a scientific echo sounder and the distribution density of moon jellyfish recorded simultaneously by an underwater video camera in small bays (Hokezu Bay and Mikame Bay) in Japan. This relation held in all of the surveys carried out in recent years (2013–2016), although the regression coefficient varied slightly from year to year due to the existence of ambient organisms. Using this relation and high-resolution echo sounder scan surveys across the bay, we obtained the spatial structures of moon jellyfish aggregations and categorized them into either patchy, layered, or wavy aggregations. We also examined possible physical mechanisms responsible for the moon jellyfish aggregations. In particular, passive particle tracking simulations of several idealized internal wave fields suggest that the formation of wavy aggregations is closely related to the presence of internal waves. However, internal waves alone cannot induce patchy and layered aggregations, indicating that particular biological processes (e.g., swimming behavior) are also necessary for such aggregations to form.