PALEOCORE TREC : Sedimentological data for palaeogenomic studies along European coastlines

All data and results produced in this study were generated as part of the TREC (Traversing European Coastlines) project, which is linked to the BIOcean5D European project (PI: R. Siano, Ifremer). The TREC expedition began in April 2023 and concluded in July 2024. During this period, researchers collected biological samples and environmental data at 115 land-sea transects along the European coastline. In this context, the Geo-Ocean research unit (UMR 6538) participated in collecting sedimentological cores and analysing all the sediment cores collected from 15 European project sites [1]. The sediment cores collected from the TREC sites mainly cover estuarine environments with very shallow waters and complex hydro-sedimentary dynamics. These combine tidal and storm influences from the sea and river catchment areas with anthropogenic pressure from economic development and polluted runoff. The coring equipment is an interface gravity corer (Ronenberg), operated by Geo-Ocean at the following sites: Roscoff, Lorient, Bay of Brest, Bay of Veys, Thau Lagoon, Bilbao and Barcelona. An Ifremer hand interface corer was used at La Tremblade, and various other corers were used at other sites by European labs associated with the TREC project. If the sediment is muddy and not too compacted, the Ifremer interface corer can recover samples of up to 85 cm, while preserving the internal structure of the sedimentary layer and its interface with seawater. The TREC strategy was to obtain five 'good quality' cores from each site (with a GPS accuracy of approximately 5 to 10 metres), each of which was assigned a name code and a letter (from A to E). The letter E indicates that the core was intended for geological analysis (e.g.  TREC-RO-IS03-CORE_E for Roscoff). The Ronanberg corer head is equipped with a GoPro camera and a spotlight to check for smooth operation on the seabed.
[1] https://www.youtube.com/watch?v=AgLvobGzgQY