Mesozooplankton biomass during Mikhail Lomonosov cruise ML32, 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.本研究采用环径36厘米、网目尺寸125微米的开闭式JUDAY网（JUDAY net）采集中型浮游动物（Mesozooplankton）。此外，还使用了网目尺寸300微米、环径80厘米的JUDAY海洋模式JOM（JOM）。该采样网的开闭机构采用南森机械锁定系统（Nansen mechanical lock system），可使网具沿标准水层（0~10米、10~25米、25~50米、50~100米、100~200米、200~300米、300~500米）垂直拖曳，并在上层水层处完成封闭。拖曳深度通过放出的钢缆长度与钢缆倾角进行测算。采集得到的10~20毫升样品采用3%~4%的缓冲甲醛溶液固定保存，并在返回实验室后开展后续处理。所有桡足类（copepods）均鉴定至属水平，其余分类类群则分别鉴定至型、纲、目及科水平。