Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1975-1984, compiled from statistics about ICCAT fishery region B14

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.海洋渔业资源管理的生态系统方法与模型开发，需要能够便捷获取的主要捕捞鱼种标准化验证历史捕捞数据集。此类数据集可用于量化渔业活动对生物量移除的影响，并评估模型性能；同时，标准化数据集的使用有助于实现不同模型间的相互比对。北大西洋长鳍金枪鱼（North Atlantic albacore tuna）全年均会受到延绳钓作业捕捞，夏季与秋季还会遭遇表层渔具作业捕捞；其渔业统计数据由大西洋金枪鱼养护国际委员会（International Commission for the Conservation of Atlantic Tunas, ICCAT）汇编整理。本数据集针对该鱼种提取了带有地理坐标的捕捞量与捕捞努力量数据，时间分辨率为月度，空间分辨率为1°或5°网格；提取过程中严格界定了渔业作业类型，并完成了数据筛查工作。本次研究针对1956年至2010年的时段，共界定了13类渔业作业，涉及的捕捞渔具包括延绳钓、曳绳钓、中层拖网与诱饵钓。不过，ICCAT数据库中可获取的空间化捕捞努力量数据仅占总捕捞量的一小部分。此外，本数据集还按照前述渔业作业界定标准，提取了1956年至2010年的捕捞体长频率数据：时间分辨率为季度，空间分辨率介于1°×1°至10°×20°之间。数据所采用的体长测量分级组距分别为1厘米、2厘米或5厘米（叉长，Fork Length）。数据筛查过程中发现了一批异常样本：部分样本的体长超过150厘米，但所有针对长鳍金枪鱼生长的研究均表明，该鱼种极少能长至130厘米以上。因此，研究人员人为设定了130厘米的阈值，将所有超出该阈值的体长频率数据从原始数据集中剔除。