In a boost for Pacific Islands such as Tuvalu under threat from rising seas, Commonwealth nations agreed on Saturday that a nation's maritime boundaries should remain fixed even if climate change causes small island states to be submerged.
The 56 countries with roots in Britain's empire issued the Commonwealth's first Ocean Declaration at the end of a summit of the group in Samoa.
The declaration says the Commonwealth leaders "affirm that members can maintain their maritime zones" under the law of the sea and that the rights that flow from them continue to apply, regardless of physical changes connected to climate change related sea level rise.
Fixing maritime boundaries means atoll nations can continue to reap the economic benefit of vast fishing grounds, even if much of the population must migrate as its dry land area is significantly reduced.
The Commonwealth move follows a campaign by Tuvalu, where 60% of residents live on an atoll scientists predict will be half submerged by tides by 2050, to secure statehood in perpetuity under international law.
The U.N. International Law Commission, which will issue a report on sea-level rise next year, in July flagged its support for a “strong presumption” that statehood would continue where a nation’s land was totally or partially submerged by rising sea levels caused by climate change.
Of the Commonwealth members, 49 have a coastline and 25 are small island developing states.
Commonwealth Secretary-General Patricia Scotland said the declaration "will give real hope to many who are frightened and are feeling no one's watching".
Samoa Prime Minister Fiame Naomi Mata'afa said the first ocean declaration by Commonwealth countries had been adopted in a region of the world where climate change is the greatest threat to security.