A perspective on the potential of using marine organic fertilizers for the sustainable management of coastal ecosystem services

Agricultural production is predicted to double during the next century. To ensure food security in response to global population growth is a challenge and will require strategies that mitigate associated environmental damage in ways consistent with United Nation’s Sustainable Development Goals. One possible approach is to utilize organic fertilizers from marine sources to improve soil structure by enhancing activities of soil organisms and restoring essential plant nutrients to the soil. Here we identify opportunities to develop organic fertilizers from two types of materials of marine origin: seagrass wrack and jellyfish biomass. Seagrass wrack often occurs as undesirable waste material on beaches. In many coastal areas around the world jellyfish bloom presents a nuisance because of negative impacts on marine ecosystem productivity. Several investigations have reported that organic fertilizers produced from seagrass and jellyfish could enhance coastal ecosystem services by reducing pollution, and by improving soil health and quality. Recent research indicates that seagrass litter improves soil water holding capacity and the nutritional value of crops; moreover, it can be used as multi-functional fertilizer, due to its content of valuable macro- and microelements. The application of jellyfish fertilizer increases soil contents of organic matter, nitrogen, phosphorus and potassium and enhances the growth and survival of seedlings significantly. In this overview we describe novel approaches regarding the utilization of seagrass and jellyfish as sources of fertilizer, and experimental studies on the influences of marine organic fertilizers on soil restoration, and implications for coastal management.