This chapter identifies eight elements of the principle of common heritage of mankind (CHM) in the context of DSM, which exhibits a delicate balance between development and conservation. Environmental protection is an integral and inherent restrictive element of CHM. The chapter reflects preliminarily upon environmental protection in DSM at the conceptual and operational levels. At the conceptual level, it argues for an erga omnes character of international environmental obligations. Such a characterization would make a big room for innovative practices with respect to a more informative, inclusive and transparent model of global environmental governance of DSM as well as have legal implications on the question of who is entitled to invoke liability of the contractor, the sponsoring State and the ISA for environmental damage. At the operational level, it highlights the significant role of marine sciences and the fact that the great gaps of current marine scientific knowledge constitute a fundamental restraint to the development of DSM as well as the environmental protection in DSM.

This chapter addresses the question of how the International Seabed Authority (ISA) discharges its environmental mandate in DSM. First, answer to this question hinges largely upon the composition, powers and functions and decision-making procedures of its organs and subsidiary bodies, in terms of both law and practice. Then, it identifies six categories of powers and obligations of the ISA relating to its environmental function. Namely, the powers to adopt rules, regulations and procedures, issue technical and administrative guidance to contractors, ensure compliance of the contractor while administering activities, issue environmental emergency order to the contractor for preventing (risk of) serious environmental damage, as well as the obligations to apply the precautionary approach, and encourage and promote marine scientific research. It argues that the ISA has changed to results-based environmental regulation. Finally, this chapter comments on the drafting work of Exploitation Regulations by the ISA and suggests ways for the LTC to assess the current state of marine scientific knowledge on a continuing basis.