CE0906 North-west Blue Whiting Acoustic Survey

An acoustic survey targeting blue whiting (Micromesistius poutassou) spawning and post spawning aggregations in the north east Atlantic in 2009. Spraying takes place from January through to April along the Shelf edge from the southern Porcupine Bank area northwards to the Faroe/Shetland Ridge including offshore areas as the Rosemary, Hatton and Rockall Banks. Peak spawning occurs between mid-March and mid April and acoustic surveys are timed to occur during this phase. To facilitate a more coordinated spatio-Temporal approach to the survey participating countries meet annually to discuss survey methods and define target areas at the ICES led Planning Group of Northern pelagic Ecosystem Surveys (PGNAPES). The survey covered the core spawning area of blue whiting to the west of Scotland and the Western Isles. The survey track commenced off the northwest coast of Ireland and progressed northwards to the Hebrides using east-west transects up to 300nmi ships. Westward extension reached the western flanks of the Rockall Bank. The survey was carried out in continuity from south to north with no scheduled or unforeseen disruptions. The 2009 survey was part of an International collaborative survey using the vessels RV Celtic Explorer (Ireland), RV Fridtjof Nansen (Russia), RV Tridens (Netherlands) and the RV Magnus Heinason (Faroes) and the FV Brennholm (Norwegian commercial charter). A parallel transect design was adopted with transects running perpendicular to the lines of bathymetry where possible. Acoustic data were collected using the Simrad ER60 scientific echosounder. Cruising speed was maintained at a maximum of 10 KTS (Knots) where possible. Biological sampling was done using a single pelagic midwater trawl. All components of the catch from the trawl hauls were sorted and weighed; fish and other taxa were identified to species level. Age, length, weight, sex, stomach fullness and Maturity data were recorded for individual blue whiting within a random 50 fish sample from each trawl haul with a further 100 random length and weight measurements were also taken. All blue whiting were aged onboard. Oceanographic data on temperature, depth and salinity (CTD) were collected at set stations.本数据集为2009年在东北大西洋开展的、针对蓝鳕（Micromesistius poutassou）产卵及产卵后集群的声学调查。 调查工作于1月至4月间沿陆架边缘开展，作业范围从南波尔库平浅滩（Porcupine Bank）以南海域向北延伸至法罗-设得兰海岭，涵盖罗斯玛丽海丘（Rosemary Bank）、哈顿海丘（Hatton Bank）、罗卡尔海丘（Rockall Bank）等近海区域。蓝鳕的产卵盛期为3月中旬至4月中旬，本次声学调查的时间安排即覆盖该产卵盛期阶段。为协调开展时空统一的调查工作，参与调查的成员国每年都会在国际海洋考察理事会（International Council for the Exploration of the Sea, ICES）牵头的北方浮游生态系统调查规划组（Planning Group of Northern pelagic Ecosystem Surveys, PGNAPES）框架下，讨论调查方法并明确目标海域。 本次调查覆盖了苏格兰以西及外赫布里底群岛周边的蓝鳕核心产卵海域。调查航线始于爱尔兰西北近海，采用东西向测线向北推进至赫布里底群岛，测线最远延伸至300海里（nautical mile），向西延伸至罗卡尔海丘的西侧陡坡。本次调查自南向北连续开展，未出现计划内或突发的作业中断。 本次2009年调查属于国际协作调查的一部分，参与作业的船舶包括：爱尔兰的“凯尔特探索者号”研究船（RV Celtic Explorer）、俄罗斯的“弗里乔夫·南森号”研究船（RV Fridtjof Nansen）、荷兰的“特里登号”研究船（RV Tridens）、法罗群岛的“马格努斯·海纳森号”研究船（RV Magnus Heinason），以及挪威商业包租的“布伦霍姆号”渔业作业船（FV Brennholm）。 调查采用平行测线设计，在条件允许的情况下，测线与等深线保持垂直。声学数据通过Simrad ER60科学回声仪采集；作业航速在条件允许的情况下保持在最大10节（Knot, KTS）。 生物采样采用单层浮游中层拖网开展：对每网次的渔获物全部组分进行分拣与称重，将鱼类及其他分类单元鉴定至物种水平。对每网次随机抽取的50尾蓝鳕个体，记录其年龄、体长、体重、性别、胃饱满度及性腺成熟度数据；此外还额外随机测量100尾个体的体长与体重。所有蓝鳕的年龄鉴定均在船上完成。 在预设站位采用温盐深仪（Conductivity Temperature Depth, CTD）采集温度、水深及盐度等海洋学数据。