Following the implementation of the WESTMED fishery management plan in 2020, the important knowledge gap about the functioning of the Gulf of Lion was underlined by all the stakeholders, professional fishermen, scientists and managers. The Goldys project (Gulf of Lion Seasonal Dynamics), is a project led by Ifremer in partnership with the CRPMEM-Occitanie, and co-financed by the FEAMP funds, France Filière Pêche and the Occitanie region until June 2023. It aims to respond to certain questions on the ecological functioning of the Gulf of Lion and the seasonal dynamics of the species exploited by trawl fleets.
In particular, through the deployement of seasonnal sea surveys, it aims to complete the summer vision of the system obtained through the existing scientific surveys occuring each year in June and July by Ifremer (MEDITS and PELMED surveys) . By applying the same protocols and observation devices as on these campaigns (to allow comparison between seasons) but by deploying them on a Mediterranean trawler, it aims to observe:

• The seasonal evolution of all the species fished by bottom trawling and living near or on the bottom,
• The reproductive cycles of a large number of them (define the spawning periods),
• Spawning and nursery areas,
• The seasonal evolution of the productivity of the environment (hydrology, phyto- and zoo-plankton communities).

The three GOLDYS seasonal surveys (spring, autumn, winter) therefore aim to cover a representative part of the Gulf of Lion by taking up some of the stations observed during the MEDITS campaign and supplementing them with professional hauls where needed. To that aims, 40 hauls per season, spanning 75 days at sea, were carried out between April 2022 and March 2023.