Biomass and abundance at length of small pelagic fish estimated during the PELGAS survey in the Bay of Biscay in springtime

the pélagiques gascogne (pelgas, doray et al., 2000) integrated survey aims at assessing the biomass of small pelagic fish and monitoring and studying the dynamics and diversity of the bay of biscay pelagic ecosystem in springtime. pelgas has been conducted within the eu common fisheries policy data collection framework and ifremer’s fisheries information system. details on survey protocols and data processing methodologies can be found in doray et al., (2014, 2017a).this dataset comprises the biomass (in metric tons) and abundance (in thousands of individuals) at length (in cm) of small pelagic fish estimated during the pelgas survey in the bay of biscay in springtime. total biomass and abundance per species on one hand, and frequencies-at-lenght per species and acoustic elementary distance sampling units (edsus) on the other hand, have been derived from fisheries acoustic and midwater trawl data based on the methodology described in doray et al. (2010). frequencies-at-lenght per species and edsus have been averaged over the survey area for each species and multiplied by the total biomass and abundance per species, to derive global biomass and abundance at length estimates. this dataset was used in doray et al., 2017b.

法国加斯科涅海洋学调查（Pélagiques Gascogne，Pelgas、Doray等，2000年）旨在评估小型浮游鱼的生物量，并对比斯开湾浮游生态系统的动态和多样性进行监测与研究，重点关注春季。Pelgas调查是在欧盟共同渔业政策数据收集框架和IFREMER渔业信息系统下进行的。关于调查方案和数据处理方法的详细信息，可参考Doray等（2014，2017a）。本数据集包括春季在比斯开湾进行的Pelgas调查中估计的小型浮游鱼的生物量（以公吨计）和丰度（以千个体计），以及按长度（以厘米计）的丰度。一方面，根据Doray等（2010）所述方法，从渔业声学和中层拖网数据中衍生出每种物种的总生物量和丰度；另一方面，基于频率-长度和声学基本距离采样单位（EDSUs）。对于每种物种，将频率-长度和EDSUs的平均值乘以每种物种的总生物量和丰度，以得出全球生物量和丰度长度估计。该数据集被用于Doray等（2017b）的研究。