Mesozooplankton average mass during Akademik Kovalevsky cruise AK7/2, Part III

Mesozooplankton was sampled by open-closing JUDAY net with a 36 cm ring diameter and mesh size of 0.145 mm. The open-closing mechanism used was the Nansen mechanical lock system allowing nets to be vertically towed through standard depths (0-10, 10-25, 25-50, 50-100, 100-200, 200-500 m) and closed at the upper depth level. Depth of tow was evaluated by wire paid out and the angle of wire inclination. The 10-20 ml samples were preserved in 3-4% buffered formaldehyde and processed on return to the laboratory. All of copepods were identified to genus level, other taxanomic groups - to type, class, order and family levels.

本研究采用环径36 cm、网目尺寸0.145 mm的开闭式JUDAY网采集中型浮游动物（Mesozooplankton）。该网具搭载南森机械锁定系统（Nansen mechanical lock system）作为开闭机构，可沿预设标准水层（0~10米、10~25米、25~50米、50~100米、100~200米、200~500米）开展垂直拖网，并在各水层的上层分界处闭合网口。拖网水深通过缆绳放出长度与缆绳倾斜角度进行测算。采集获得的10~20 mL样品经3%~4%缓冲甲醛（buffered formaldehyde）固定后，带回实验室进行后续处理。所有桡足类（copepods）均被鉴定至属级水平，其余分类类群则分别鉴定至型、纲、目及科级水平。