What does it mean to pollute the World Ocean? Earth is different from any other planet we know about because it has a large amount of water, and about 97 percent of this water is found in the World Ocean. The World Ocean is that ensemble of interconnected oceans and seas. Most of the world’s habitat is found in the World Ocean because not only does this ocean take up more than 70 percent of Earth’s surface, it has a depth – the water column – that harbors life throughout. Indeed, most “ecosystem services” come from marine systems (Costanza 2000). Ecosystem services are direct and indirect benefits to human societies that spring from the functions of ecosystems (Hassan et al. 2005) and they can fall into four categories: provisioning, regulating, cultural, and supporting services. The ocean provides fish for us to eat (see Chapter 36), it regulates the climate (see Chapter 28), provides the cornerstone of the entire hydrologic cycle that brings freshwater to us, and provides spiritual, educational, economic, and recreational opportunities for people around the world. Finally, and perhaps most importantly, the World Ocean provides supporting services in cycling nutrients and elements, such as carbon, that then provide the grounds for all the other services.