GOLDYS bottom trawl surveys catch data : Bentho-demersal assemblages of the Gulf of Lion (North-western Mediterranean) in 2022-2023

The Goldys project (Seasonal Dynamics of the Gulf of Lion, 2021-2023) aims to obtain a better understanding of the life cycles, spatial distributions and dynamics of exploited populations via seasonal monitoring of the resource. By collecting standardized observations throughout the year, it completes the summer vision of the system obtained through yearly scientific surveys deployed in June by Ifremer during the MEDditerranean International Trawl Surveys (MEDITS). By relying on the same protocols and observation devices as MEDITS (to allow seasonal comparison) but by deploying them from a Mediterranean trawler (Vaz et al., 2023a), it aims to observe the seasonal evolution of all demersal or benthic species caught by bottom trawls and the reproductive cycles of a large number of them. A total of 40 operations per season, spanning 75 days at sea, were carried out between April 2022 and March 2023. This information may be used to define the spawning periods and map spawning and nursery grounds. The data obtained make it possible to answer certain questions on the ecological functioning of the Gulf of Lion and the seasonal dynamics of species exploited by trawl fleets (Vaz et al. 2023b).

戈迪斯项目（里昂湾季节动态研究，2021-2023年）旨在通过对渔业资源的季节性监测，更深入地解析渔业开发种群的生命周期、空间分布与种群动态。项目通过全年采集标准化观测数据，填补了法国海洋开发研究院（Ifremer）每年6月借助地中海国际拖网调查（Mediterranean International Trawl Surveys，缩写MEDITS）所获取的夏季系统观测数据的空白。本项目沿用与MEDITS完全一致的调查规程与观测设备，以保障季节性对比的可行性，同时改为在地中海拖网渔船上开展作业（Vaz等，2023a），旨在观测底拖网捕获的全部底层或底栖物种的季节演替规律，以及其中多数物种的繁殖周期。2022年4月至2023年3月期间，项目按季度累计开展40次作业，单次海上作业周期为75天。该观测数据可用于明确物种产卵期，并绘制产卵场与育幼场空间分布图。所获数据集可用于解答里昂湾生态系统运作机制，以及拖网船队开发渔业物种的季节动态相关问题（Vaz等，2023b）。