Fertilization by iron Iron is a so-called limiting factor for algal growth in Antarctica. If there be more iron in the waters, then more algae would come to bloom (and die) they would capture more carbon, and maybe store more carbon on the bottom of the ocean. This has brought daring entrepreneurs in the past to the hypothesis that artificially fertilizing the Southern Ocean with extra iron, would cap more carbon and thus solve a little bit of the climate crisis we’re in.