2020年秋季南极布兰斯菲尔德海峡南极磷虾集群时空分布

南极磷虾是南极海洋生态系统中的关键物种,具有重要的商业开发潜力,但其集群的类型与分布存在较大时空异质性,这增加了南极磷虾资源评估的难度,也对南极磷虾渔业的海上作业与企业生产安排带来了较大的挑战.为了探究布兰斯菲尔德海峡渔场内南极磷虾的集群分布和结构特征,提高渔船作业效率,基于渔船采集的声学数据,分析其时空分布特征,昼夜...

Temporal and spatial distribution of Antarctic krill (Euphausia superba) swarms in the Bransfield Strait, Antarctic in autumn 2020

Antarctic krill (Euphausia superba) is a key species in the Antarctic marine ecosystem with important potential for commercial exploitation, however significant heterogeneity in type and distribution of krill swarms exacerbate the difficulty of biomass estimation and also bring the challenge for at-sea operation and working plan of fishing company. Therefore using acoustic data collected from fishing vessel, the spatial and temporal distribution characteristics, diel differences, and swarm structures of Antarctic krill swarms in the fishing grounds of the Bransfield Strait with the aim of improving fishing efficiency. The results indicate that, in the Bransfield Strait, krill swarms are primarily located in the southern shelf waters in autumn 2020, and that the number of krill swarms increases over time during autumn. Most krill swarms can be found in layers between the surface and 150 meters, but some swarms also occur close to the bottom. The diel distribution of krill swarms varied, with a general tendency of reversed diel vertical migration that moves up to the surface in the daytime but sinks to the deeper layer at night. The layered type of swarm with a high density is dominant in the daytime, while scattered type of swarm with low density occupies a high proportion at night. The density within swarms is correlated positively with swarm length, with long layered type of swarms has the highest density and been more suitable for fishing. Understanding krill swarm distribution is beneficial for understanding their formation characteristics of krill fishing ground as well as enhancing the productivity and profitability of fishing vessels.