These data are outputs of a spatio-temporal model inferring fish distribution. The maps are based on high-resolution catch data (VMS-logbook). They have a montly time resolution and a 0.05° spatial resolution. Four demersal species of the Bay of Biscay are available in the dataset: common sole (Solea solea), megrim (Lepidorhombus whiffiagonis), anglerfish (Lophius spp) and thornback ray (Raja clavata). Maps are provided for year 2008 to 2018 ; they were produced in the context of the MACCO project (https://www.macco.fr/en/accueil-english/), an Ifremer project that aims at proposing alternative management strategies for the mixed demersal fisheries of the Bay of Biscay.

The observation of ecosystems by Ifremer's Fisheries Information System (SIH) is based on a network of sea cruises. It aims to assess the state of stocks of the various species fished in France and Europe. It also enables the characterisation of the marine ecosystem in which the populations evolve. 23 scientific cruises take place each year at sea, enabling data to be collected for more than 30 years for the oldest. Thanks to the use of standardised fishing gear, the data acquired each year on board scientific vessels or professional fishing vessels contribute to the calculation of the index of abundance, with thousands of fish taken during timed trawls. The fish are measured and their age is assessed by measuring their otoliths (small bones located in the inner ear of the fish).