This project is very interesting, since they are taking advantage of an element that is harmful in the sea, such as sargassum, to turn it into something beneficial and productive, such as what you describe (compost, dune reconstructor, element that prevents beach erosion, etc.). It would be ideal to know the results of this project in the medium and long term, although since it lacks experimental character, it will surely have a good impact on the ecosystems in which it is developed. Good post, interesting idea. Best regards.