Mesozooplankton average mass during Mikhail Lomonosov cruise ML27, Part III@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.本研究使用环径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）样本。此外，还采用了网目尺寸300 µm、环径80 cm的JUDAY海洋模式JOM（JUDAY oceanic model JOM）。本次使用的开闭机构为南森机械锁定系统（Nansen mechanical lock system），该系统可使网具在标准水层（0~10 m、10~25 m、25~50 m、50~100 m、100~200 m、200~300 m、300~500 m）中垂直拖曳，并在该水层的上层边界处闭合。拖曳水深通过放出缆绳的长度与缆绳倾角进行测算。采集得到的10~20 ml样本经3%~4%缓冲甲醛（buffered formaldehyde）固定后，在返回实验室后进行处理。所有桡足类（copepods）样本均鉴定至属级，其余分类类群则鉴定至型、纲、目及科级水平。