机构地区:[1]上海海洋大学海洋科学学院,上海201306 [2]中国水产科学院南海水产研究所,广东广州510300 [3]上海海洋大学大洋渔业资源可持续开发教育部重点实验室,上海201306 [4]上海海洋大学国家远洋渔业工程技术研究中心,上海201306
出 处:《中国水产科学》2018年第6期1317-1324,共8页Journal of Fishery Sciences of China
基 金:国家自然科学基金项目(41776185;41606210);国家重点研发计划项目(2018YFC1406801);农业部南极海洋生物资源开发利用项目(D8002-18-0097)
摘 要:为确定南奥克尼群岛海域南极磷虾(Euphausia superba)集群特征,本研究根据2017年3-4月我国南极磷虾探捕项目采集的断面声学数据,使用通用声学数据后处理软件,研究了该海域的南极磷虾集群特征信息。本研究共检测并提取了2539个磷虾集群的高度、长度、分布深度、集群间距、集群面积及集群磷虾密度信息,其中白天集群1389个,夜晚集群1150个。通过集群特征值的统计,将该海域集群分为3类。聚类A的虾群密度最大[(19.24±27.00)ind/m^3],聚类B的虾群最深[(174.74±53.30) m],聚类C的虾群面积最大[(2868.62±2149.75) m^2]。聚类A和聚类B的集群长度无显著性差异(P>0.05),聚类A和聚类C的集群深度无显著性差异(P>0.05)。A类集群主要分布在南奥克尼群岛北部及西北部的深水区,水深>1000 m。B类和C类集群在整个调查海域均有分布,其中B类集群多分布在群岛大陆架海域,水深<200 m。不同区域的集群分布信息不同,离岛屿最远的东西两个断面集群较少,分布比较分散。本研究结果表明大部分的磷虾个体位于少数的大型集群中,集群磷虾密度和集群间距间存在正相关关系;未来通过磷虾集群与外界因子(环境因子,捕食者)相关性的研究,可以帮助我们更为准确地了解集群结构与形成机制,预测磷虾资源分布。Knowledge about swarm dynamics and underlying causes is essential to understand the ecology and distribution of Euphausia superba. We examined swarms across the South Orkney Islands in March and April 2017 using the Simrad EK60 (38 and 120 kHz) echosounder, concurrent with net sampling. The acoustic data were analyzed by applying a swarm-identification algorithm, and then filtering out all non-krill targets. A total of 2539 krill swarms with swarm characters including swarm height and length, packing density, swimming depth, and inter-swarm distance were extracted, of which 1389 were daytime swarms and 1150 night swarms. Compared with those of the night swarms, krill aggregated in deep waters during the daytime with lower packing density and smaller inter-swarm distance. There were significant differences between day and night krill swarms. Through the multivariate analysis, the krill swarms were divided into three categories, which differed in both their dimensions and packing density. Group A presented the highest swarm density [(19.24±27.00) ind/m3], Group B swarms pre-sented the deepest distribution depth [(174.74±53.30) m], Group C presented the largest swarm area [(2868.62± 2149.75) m2] with the longest swarm length [(258.76±322.88) m]. There was no significant difference in swarm length between Groups A and B and no significant difference in swarm depth between Groups A and C. Group A swarms were mainly distributed in deep water areas in the north and northwest regions of the South Orkney Is-lands at a depth of 〉1000 m, and mainly occurred during daytime. Groups B and C swarms were distributed throughout the survey area; Group B swarms were aggregated in the continental shelf at a water depth of 〈200 m. The results suggest that the majority of krill were contained within a minor fraction of the total number of swarms, and there was a positive correlation between packing density and inter-swarm distance. The results also provide valuable information on the distribution of krill
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...