In regions of the ocean that are distant from deserts or that are not reached by dust-carrying winds (for example, the Southern and North Pacific oceans), the lack of iron can severely limit the amount of primary production that can occur.
Naquelas rexións oceánicas nas que non hai un aporte de ferro, como pode ser o caso do Pacífico Sur e Norte, a falta de ferro pode limita severamente a produción primaria.