Disputes concerning the marine environment, which supports the vast majority of the planet's biological diversity, have been the subject of ongoing international judicial attention since the Bering Sea Fur Seals case was decided in the late nineteenth century. This litigation has intensified as the marine environment has faced increasing pressures. Among the most serious threats include climate change, pollution from terrestrial, marine, and atmospheric sources, and the unsustainable exploitation of marine living organisms. Disputes relating to several of these threats have found their way before international courts and tribunals, including the ITLOS which has come to play a prominent role in global efforts to protect ocean ecosystems.

This chapter examines this dynamic area of international environmental jurisprudence, from the earliest fisheries cases through to recent litigation under the compulsory procedures established by the LOS Convention. The first section of the chapter examines the plentiful case law relating to the exploitation and conservation of ocean resources. This section is in turn divided into two sub-sections, with one dealing with disputes relating to the limits of the jurisdiction of littoral states over fisheries and other marine wildlife in adjacent waters, and the other discussing cases concerning the exploitation of straddling and high seas fisheries. The second section of the chapter discusses the more limited collection of cases dealing with issues of marine pollution.