The original Friends of Nature Belize, now Southern Environmental Association (SEA Belize), was formed in 1993 when a group of Placencia residents, concerned about the inevitable impact of tourism on Laughing Bird Caye - a small and beautiful island about 12 miles offshore, decided to do something positive. Fishermen were camping there and at the same time tour guides were starting to bring tourists for snorkeling. The citizens formed a committee called Friends of Laughing Bird Caye to look after the island and lobby for its protection.

The committee made a major achievement in 1996 when Ministry of Natural Resources granted Laughing Bird Caye 'National Park'  status, and so an officially protected area. At that time FoLBC organized a very effective voluntary ban on fishing and camping in the park. Later in 1996 Laughing Bird Caye National Park became one of seven marine protected areas along the Belize Barrier Reef to be declared a collective World Heritage Site by the United Nations Educational, Scientific, and Cultural Organization (UNESCO).

During this time researchers and community members were also learning about an area on the reef called Gladden Spit, where thousands of fish were aggregating at predictable times to spawn. Fishermen had worked these aggregations heavily for many years. Whale Sharks were also visiting the area in noticeable numbers, apparently feeding on the fish spawn. Funding by the World Wildlife Federation (WWF) enabled the Fisheries Department and Friends of Laughing Bird Caye to conduct a series of consultations that led to the declaration of the Gladden Spit and Silk Cayes as a Marine Reserve in May 2000.

In 1998 another NGO, Friends of the Placencia Lagoon, was formed to bring attention to the fragile ecosystem of the lagoon, located west of the Placencia Peninsula. Many shrimp farms were being established on the shores of the lagoon, and there was concern about the effects of the generated waste disposal on the life of the lagoon.

In March 2002, dedicated members of these two very vital and ecologically important community groups officially registered the consolidated organization as Friends of Nature Belize, now SEA Belize. This new organization was soon charged with the responsibility of co-managing the Gladden Spit Marine Reserve and Silk Cayes Marine Reserve on behalf of the Belizean coastal communities of Hopkins, Riversdale, Independence, Monkey River, Maya Beach, Seine Bight and Placencia. In 2008, the new organization SEA Belize now encompasses the Sapodillo Cayes region in Southern Belize in its protected areas.

Among the major achievements since 2002 is a buoy program for Gladden Spit and Silk Cayes demarking these protected areas as a "No Take" zone. In the southwestern end of the reserve appoximately 5% of the total area, including the three Silk Cayes, also known as the Queen Cayes, thrives and offers some of the best patch reefs in Belize.

A conch restoration zone has been established on the back reef flats on the northeastern end of the reserve and, in an effort to reduce anchor damage to the fragile reef ecosystem, mooring buoys have been professionaly installed by Placencia Mooring Masters in the very popular Silk Cayes area, which sees thousands of visitors each year during the Whale Shark Watch season.