This project is a continuation of SNIC 2022/22-411 Sponges are the oldest animal group still living on our planet. Today, although often neglected, the sponge fauna represents one of the most diverse macrobenthic animal groups. There are ~9,600 species of sponges described today with 138 found on the Swedish west coast. One of the most abundant and iconic deep-sea Swedish species is Geodia barretti (fotbollssvampdjur), a massive white animal, which can reach 80 cm in maximum dimension and reach more than 38 kg. Continental shelves and slopes of the cold-temperate north Atlantic accommodate large populations of this species creating what are now called ‘sponge grounds’. We have recently sequenced and published the whole genome of this species that we would now like to use in a population genetic study (ddRADSeq) across the North Atlantic. The data is already sequenced and processed but analyses remain to be done.