Cold-water corals are found throughout the world’s oceans, with some species, such as Lophelia pertusa or Desmophyllum dianthus, being found in every ocean around the globe. So when animals, like corals, are sessile (firmly attached in one place) how do they get from one ocean to another? This is where their reproductive strategies come in. Though the corals themselves do not get up and move around, their larvae can be carried in strong ocean currents from one place to another, sometimes covering many hundreds of miles before settling down turning into adult corals anchored in place. Once these corals are grown and produce their own larvae, the next generation can then be taken another great distance away, thus hop-scotching across the world’s oceans, spreading and creating new populations, that may later form new reefs and mounds.
For more information on the reproduction of cold-water coral, you can read about Rhian Waller's work on coral spawning.