The marine environment is subject to many legal regimes, some applying only within defined regions. In the cases of the Arctic and the Antarctic, significant regional initiatives include the regimes created by the 1959 Antarctic Treaty and its 1991 Environmental Protocol, as well as those adopted under the 1991 Arctic Environmental Protection Strategy and the 1996 Arctic Council. Beyond such regional regimes, there exists a sizeable body of international law which applies globally: legal regimes which set out to impose obligations upon all states, in principle covering all parts of the earth.

Developments in international environmental law during the past three decades have seen the emergence of several core principles which provide a framework of customary environmental law. These principles include: the obligation of all states to conserve the environment and its natural resources; the obligation upon states to assess potential, and monitor actual environmental impact; the obligation upon states to conserve the environment both within and beyond areas of national jurisdiction; and sustainable development.

This list is not exhaustive; it may well be possible to identify other principles which are in a state of development, or which have particular application for specific environmental problems. These principles of international environmental law, emerging from state practice as well as incorporated in international environmental instruments, provide the underlying framework for marine environmental protection globally, thus including the polar regions.