Mesozooplankton adundance during Mikhail Lomonosov cruise ML30, Part V@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.本研究采用网口直径36 cm、网目尺寸125 µm的开闭式JUDAY网（open-closing JUDAY net）采集中型浮游动物（Mesozooplankton）。此外，本次采样还使用了网目尺寸300 µm、网口直径80 cm的JUDAY海洋模式JOM（JUDAY oceanic model JOM）。该网具采用南森机械锁定系统（Nansen mechanical lock system）作为开闭机制，可实现网具沿垂直方向在标准水层（0~10 m、10~25 m、25~50 m、50~100 m、100~200 m、200~300 m、300~500 m）间拖曳，并在上层水层位置闭合。拖曳水深通过放出的钢缆长度与钢缆倾斜角进行测算。采集得到的10~20 mL样品采用3%~4%的缓冲甲醛（buffered formaldehyde）固定保存，返航抵达实验室后开展后续处理工作。所有桡足类（copepods）均被鉴定至属级阶元，其余分类类群则分别鉴定至类群、纲、目及科级阶元。