With rising concern about ocean degradation and the sustainable use of ocean resources, small island states must build scientific expertise that goes beyond their national needs and that benefits the oceans generally, a meeting of UN scientific experts has heard. Small island developing states (SIDS) are the “custodians” of vast ocean spaces that are important for global food security, biodiversity, natural resources and carbon sequestration, and broader sustainable ocean policies will in turn enhance their own economic development, say experts.