The Sulu-Sulawesi Marine Ecoregion (SSME), as the apex of the Coral Triangle, is considered the center of the center of marine biodiversity where the highest number of colorful reef and marine fishes, various sizes of corals and shells, myriad shapes of algae, and protective mangrove forests are found. The SSME's marine aquarium is not only a delightful lure for tourists but is also the source of food and a natural capital for livelihoods among coastal communities. To address threats to SSME's diversity and productivity, an ecoregion conservation plan was forged collaboratively by Indonesia, Malaysia, and the Philippines in 2004. As the management framework to address threats to its diversity and productivity, the SSME Ecoregion Conservation Plan has spurred the development of three comprehensive action plans for 2010-2012. These plans are implemented by the subcommittees on Migratory and Threatened Species, Marine Protected Areas and Networks, and Sustainable Fisheries, and guided by the SSME's Tri-National Committee. This publication includes business plans and cost estimates to implement the three action plans—-providing useful guide on costs and activities for governments, prospective donors, and investors; valuable information from cost-benefit analyses; and lessons learned from past conservation efforts.