Environmental DNA Marine France Evhoe 2021

Environmental DNA complements scientific trawling in surveys of marine fish biodiversity (Dataset 2021) At the end of October and the beginning of November 2021, we selected 18 sites from the 2021 EVHOE survey for eDNA sampling. The French international EVHOE bottom trawl survey is conducted annually in autumn in the Bay of Biscay (BoB) to monitor demersal fish resources. All selected sites were located on the continental shelf at depths ranging from 30 to 230 m. At each site, we sampled seawater using an underwater pump equipped with two peristaltic heads (subspace), mounted on Ifremer’s Pagure sledge. We collected approximately 30 liters of water directly from the seabed at a flow rate of 1.0 L min⁻¹. For filtration, we used VigiDNA 0.20 μm filtration capsules (SPYGEN, Le Bourget-du-Lac, France) along with disposable sterile tubing. Each filtration device processed water along a transect, representing two replicates per sampling site. To prevent contamination during fieldwork, we adhered to strict protocols, including the use of disposable gloves and single-use filtration equipment. At the end of each filtration, we emptied the remaining water from the capsule and replaced it wit