Tomorrow marks World Oceans Day, the idea for which was originally conceived 20 years ago at the 1992 Earth Summit in Rio de Janeiro. With the UNCSD Rio+20 just weeks away, the issue is of particular importance in the context of building a ‘Green Economy,’ as well as for food and nutrition security. While the Landscapes Blog has not devoted considerable attention to oceans or the marine environment, they are obviously critical to the well-being of people, the production of food, and the health of natural systems. In fact, with 71% of the Earth’s surface covered by oceans, the health of terrestrial agricultural landscapes and seascapes are inextricably linked.
Actions on land have considerable impacts on the health of marine systems. In the United States, for instance, nutrient pollution from nitrogen and phosphorous fertilizer use in the “corn belt” has contributed to a hypoxic environment in the Gulf of Mexico. Coastal dead zones, where the oxygen in the water column has been consumed and marine life can’t exist, make up an area of around 250,000 square km around the world, particularly where major rivers meet the sea. Land management practices have direct impacts, where actions taken in agricultural and forestry systems to reduce erosion and runoff can have positive consequences for downstream ecosystems. 
Coastal communities rely on marine fisheries for food, nutrition, and their livelihoods. Oceans provide around 16% of animal protein for the world and are a vital source of food for coastal communities. Approximately 40% of the global population lives within 100 km of a shoreline, making the likelihood of relying on marine ecosystems in some way very strong. Ocean fisheries also form the primary basis for over 250 million people’s livelihoods. [2, 3]
Ecosystems at the interface of land and sea protect both people and nature. For example, mangroves, found along tropical subtropical marine coastlines, serve as nurseries for many aquatic species, include fish that contribute both to food security and economies. At the same time, these ecosystems protect the coastlines from extreme weather events, mitigate against the impacts of rising sea levels, and reduce the vulnerability of those human communities. However, 35% of mangroves globally have been lost of converted, largely for coastal development or aquaculture. [2, 4]
World Oceans Day inspired the exploration of a topic off the beaten agricultural landscapes path. We welcome comments, particularly about the role of marine and coastal zones in integrated landscape approaches.
 World Bank. 2012. The Little Green Data Book 2012.
 UNEP. 2012. A Green Economy in a Blue World.
 IPCC. 2012. Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change [Field, C.B., et al (eds.)]. Cambridge and New York: Cambridge University Press.