Chapter 8 considers the regulation of seabed activities within and beyond national jurisdiction. First, the legal framework for seabed activities within national jurisdiction is examined, highlighting the central role played by coastal States, the basic rules that apply by virtue of UNCLOS, and the opportunities for supplementary global or regional rules to improve marine environmental protection. The chapter undertakes a case study of the development of rules and standards relating to the hydrocarbon industry. The chapter then turns to the regulation of seabed activities beyond national jurisdiction. In this context, UNCLOS confers significant legislative and enforcement powers on the International Seabed Authority, which acts on behalf of the international community to regulate deep-seabed mining. The chapter analyses the way in which environmental protection has been integrated into Regulations to date, and discusses future challenges remaining in this respect.