Mesozooplankton abundance during Mikhail Lomonosov cruise ML30, Part IV@en

Mesozooplankton was sampled by open-closing JUDAY net with a 36 cm ring diameter and mesh size of 125 µm. Additionally, the JUDAY oceanic model JOM with 300 µm mesh size and 80 cm ring diameter was used. 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, 200-300, 300-500 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.中型浮游动物（Mesozooplankton）样本采用环径36厘米、网目尺寸125微米的开闭式JUDAY网采集。此外，本研究还使用了网目尺寸300微米、环径80厘米的JUDAY海洋模式JOM。该采样装置采用南森（Nansen）机械锁定系统，可使网具沿标准水层（0~10 m、10~25 m、25~50 m、50~100 m、100~200 m、200~300 m、300~500 m）进行垂直拖网，并在各水层的上层边界处关闭网具。拖网水深通过放出的缆绳长度与缆绳倾斜角进行测算。采集得到的10~20毫升样本经3%~4%缓冲甲醛溶液固定保存，于返回实验室后开展后续处理。所有桡足类（Copepods）均被鉴定至属级分类阶元，其余分类类群则分别鉴定至型、纲、目及科级分类阶元。