After providing an introductory overview of the major land-based threats to the marine environment, this article focuses upon the specific global and regional efforts to address land-based marine pollution and activities through a four-part survey. The main international initiative is first described, namely, the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities (GPA). Progress in GPA implementation is next assessed with an emphasis on the documentation and results from the Second Intergovernmental Review Meeting on Implementation of the GPA held in October 2006. Major challenges constraining GPA implementation are then summarized, including limited national participation, limited financing, and limits of a non-legally binding approach. Finally, regional agreements and initiatives to counter land-based marine pollution and activities are reviewed. Progress and challenges in GPA implementation at the regional seas level are highlighted.