In September 1492, Christopher Columbus, on his first voyage to the Americas recorded “much weed ... in some places so thick that it actually held back the ships”. Three years ago, I was fortunate to travel out from Bermuda to get some flavour of the Sargasso Sea myself after the launch of the Sargasso Sea Alliance, a partnership led by the Government of Bermuda to protect the “golden floating rainforest of the Atlantic Ocean”.Nowadays mats as big as those Columbus saw are rare but what remains is no less impressive. Teeming with wildlife and camouflaged creatures, I was amazed to see juvenile turtles, tiny marlin that looked like identical versions of their adult selves, and to learn of the endemic Sargassum frogfish which has adapted to climb its way through the thick Sargassum mats in search of prey. It is indeed a unique two million square mile open ocean ecosystem.The Sargasso Sea also serves as a major feeding and migration route for a number of threatened and endangered species including humpback and sperm whales, as well as for commercially important tunas and billfish. While eels may not be the most charismatic of species, this is the only place in the world where the American and European eels spawn, thousands of miles from the fresh water in which they live.This ecologically unique and important place is at risk — threatened by climate change and ocean acidification as well as more immediately by fishing and shipping pressures, and by the accumulation of plastic and other pollutants.Held in place by the currents of the sub-tropical North Atlantic gyre, the Sargasso Sea is the world’s only sea without coasts; only the islands of Bermuda have direct coastal frontage. Bermuda already has an outstanding record in the management and conservation of its marine areas; its coral reefs are among the best preserved in the world, its pioneering ban on fish-potting, and its stewardship of its inshore waters and resources are justly famous.In March 2014, the Government of Bermuda, as the leader of the Sargasso Sea Alliance, will be welcoming Ministers from about a dozen foreign governments for the adoption of the Hamilton Declaration on the Collaboration for Conservation of the Sargasso Sea. This Declaration will establish an international Sargasso Sea Commission, based in Bermuda, to be a custodian and steward for the future. We hope that the governments represented will include the US, UK, Portugal and the Azores, the Dominican Republic, the Bahamas, Trinidad and Tobago, South Africa, The Netherlands, Belgium and Ireland. They will pledge support for the initiative to protect the Sargasso Sea.Next year, the world will be watching Bermuda. The Hamilton Declaration is designed to demonstrate the leadership of Bermuda in international marine conservation. The current discussions about the establishment of a marine reserve offer a chance for all Bermudians to show the international community how you are continuing your legacy of leadership in marine conservation.Leadership on marine conservation has to begin at home.This is why the Sargasso Sea Alliance so strongly welcomes the current Government consultation and urges Bermudians to vote in favour of a marine reserve in Bermuda waters. You may have different views on the size and shape but please do support it.Dr Freestone is executive director of the Sargasso Sea Alliance, a partnership led by the Government of Bermuda, in collaboration with scientists, international marine conservation groups and private donors, who all share a vision of protecting the unique and vulnerable ocean ecosystem of the Sargasso Sea.