The Memorandum of Understanding (MoU) for the Conservation of Cetaceans and their Habitats in the Pacific Island Region is a Multilateral Environmental Memorandum of Understanding concluded under the auspices of the Convention on Migratory Species of Wild Animals (CMS), also known as the Bonn Convention, and in collaboration with the Pacific Regional Environment Programme (SPREP). The MoU provides an international framework for coordinated conservation efforts to improve the conservation status of the Pacific Islands Cetaceans and came into effect on 15 September 2006.

The sei whale is a baleen whale. It is one of ten rorqual species, and the third-largest member after the blue and fin whales. They can grow up to 19.5 m (64 ft) in length and weigh as much as 28 t. Two subspecies are recognized: B. b. borealis and B. b. schlegelii. The whale's ventral surface has sporadic markings ranging from light grey to white, and its body is usually dark steel grey in colour. It is among the fastest of all cetaceans, and can reach speeds of up to 50 km/h (31 mph) over short distances.