From the Pew Charitable Trusts: (see also Sargasso Sea)

The Bermuda Blue Halo scheme proposes turning much of the sea within a 200-mile radius of the Island — covering an area the size of the British Isles and encompassing about 180,000 square miles of ocean — into a “no take” zone, severely limiting all activity there.  In order to protect the habitat and species within, marine reserves are typically no-take areas where there is limited human interaction. This allows overfished and overused areas to revert back to their naturally pristine state. There is scientific proof that in marine reserves fish stocks increase, the fish tend to grow larger and there is a “spill over” effect into areas outside of the reserve.  ​With this in mind, the reserve around Bermuda will have an inner and outer ring. In the inner ring (the area that is closest to Bermuda), current activities will not change. The idea is not to impede Bermudians who earn their livelihood through marine activities (both commercial and recreational). The outer ring, however, will encompass the reserve. Government said on April 10 that the results of the public consultation on Blue Halo were still being reviewed and would go before Cabinet soon.

Bermuda—the oldest and most populous of Britain’s Overseas Territories—is located in the North Atlantic Ocean, almost 1,000 kilometers (700 miles) from the East Coast of the United States. Its islands are made up of limestone formations that sit on the largest of three volcanic seamounts formed more than 110 million years ago. Globally important seagrass meadows, coral reefs, mangrove swamps, diverse marine life, and an extensive network of underwater caves are found here.

The warm waters of the Gulf Stream (a powerful Atlantic Ocean current) enable Bermuda’s shallow near-shore waters to support the northernmost coral reef system in the world. Approximately 4,600 of Bermuda’s more than 8,000 species are found in its blue waters. Thirty-six of these marine species are recognized as threatened by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, including the green turtle and oceanic whitetip shark. Sixteen species of whale, seven of dolphin and ten of sharks are known to live in Bermuda’s waters.

Bermuda and its surrounding waters lie within the Sargasso Sea, an enormous mass of water that is driven in a clockwise direction by strong ocean currents. Floating on its surface are large mats of unique seaweed known as Sargassum, which support a unique variety of marine life. Scientists have documented that eel species from European and North American rivers migrate here to spawn. Their young then make their way back to live in these rivers. The Sargasso Sea also plays an important role in the life cycle of the porbeagle shark, which is considered “vulnerable” by the IUCN Red List of Threatened Species. Recent research has found that the Sargasso Sea serves as critical birthing grounds for the shark species. Given this highly productive ecosystem, scientists, Bermudians and others are concerned about protecting this area from emerging threats, such as proposals to harvest Sargassum for biofuel.