For more than 25 years, the Association for Nature, Environment and Sustainable Development Sunce has been working to protect nature and the environment, advocating for positive changes locally, regionally, nationally and in Europe for the sustainable development of communities. As a non-governmental and non-profit organization, its mission is to advocate, educate and inform about environmentally responsible solutions based on professional and research work. Sunce's vision is a Croatia with preserved natural values, sea, coast and communities that base their development on sustainability and a circular economy.

The Association's areas of activity include environmental and nature protection, sustainable development, human rights, education, science and research, international cooperation, health and democratic political culture. Sunce has been investing significant efforts in the preservation of the Posidonia meadow, and has been monitoring this habitat in marine protected areas and ecological network areas for many years, as well as pressures on it. They advocate for better regulation of anchoring in Posidonia and the establishment of ecological anchorages. Sunce has mapped more than 500 km2 of the Adriatic seabed and coordinated the development of management plans for 27 coastal and marine protected areas and 70 ecological network areas, which have been officially adopted. So far, more than six tons of marine litter have been removed in environmental actions organized by Sunce, and more than 17,000 participants of all ages have attended Sunce's educational activities. By producing expert documents, studies, advocacy campaigns and implementing projects, in cooperation with EU partners, Sunce is becoming one of the leading organizations for nature and environmental protection in Croatia.