NourDem scientific cruises consist of sampling in estuarine and coastal sectors using the GOV trawl (Large Vertical Opening) "Ifremer / NourDem 11.90-16.45m". This trawl is operated from small professional trawlers, about ten meters in length and less than 2 meters in draft, so as to be able to sample the most upstream sectors of the estuaries (down to zero of salinity), including the foreshore area at high tide, areas where nurseries are located for many species (case of sea bass Dicentrarchus labrax or sole, Solea solea, for example). When fishing, this trawl sweeps the seabed over a width of around 7m, and its vertical opening is between 2.20m and 2.40m.

The aim of these cruises is to produce annual abundance indices for the main species living in the estuary, which can be used :

• either locally, by local managers (Marine Parks, GIP, Communities of communes, etc.) as part of their monitoring, preservation, information/knowledge dissemination missions;
• or by the ICES (International Council for the Exploration of the Sea) working groups, in charge of assessing the state of exploited stocks and drawing up management recommendations on behalf of the European Union and the Member States.

The cruises last 8 days each, which allows about 70 trawl lines to be taken depending on the sector.

The data produced is "public" and therefore usable. It is therefore necessary to mention the partnerships and projects that enabled their acquisition.
The data were acquired as part of the "NourDem Douarnenez 2018" project. This project was financed by the French Agency for Biodiversity, the Parc Naturel Marin d'Iroise (PNMI) and Ifremer. Ifremer was the project manager, with the PNMI acting as assistant to the project manager.

All requests for campaign data should be made to Ifremer's Harmonie desk at the following address harmonie@ifremer.fr