After a long campaign, that started in the early 1990s, Cabbage Tree Bay (Shelly Beach, Manly) was finally declared a marine sanctuary in 2002. It is Sydney’s only “no-take zone” to date. In consultation with various community groups, DECCW NSW (the Department of Environment, Climate Change and Water) subsequently developed a management plan to protect the bay’s marine life and make it a safe place for leisure activities.

The Manly Environment Centre decided to put on an event on the Saturday closest to Earth Day (Sat, April 24th) to get the local community involved. The event was called "A Day at the Bay: An Earth Day Celebration" and ran from 10am to 4pm on Saturday, April 24th, 2010. The main area was Shelly Beach but there were also activities along Marine Parade, leading up to Manly Beach.

The Manly Environment Centre (MEC) managed to get a number of environmental organisations and locals on board, such as DECCW NSW, National Parks and Wildlife Service, Department of Industry & Investment NSW (Fisheries), North Head Sanctuary Foundation & Threatened Plant Nursery, Eco Divers, Manly Council, National Parks Association, involved locals, experts and Local Artists.

Activities during the event included:

• Opening of the event with an Aboriginal smoking ceremony and a speech by the mayor of Manly Council
• Children’s art project: colouring-in banner portraying marine life of the bay, designed by an intern from Southern Cross University
• Free rock platform walk guided by a Fish Care volunteer from nearby Long Reef Aquatic Reserve and free nature trail walk guided by an author and a wildlife photographer
• Free guided snorkeling tours every half hour by Eco Divers
• Interpretive signs/panels along Shelly Beach and Marine Parade, explaining the local fauna and flora (told like a fairytale with colorful photos),  developed by a team of interns from Southern Cross University
• Information stalls by all groups involved
• Separate stall for people to make submissions, make themselves familiar with and knowledgable about the management plan
• Local artists, painting 'en plein air'
• The event relied heavily on the involvement of volunteers, students and passionate residents, the “friends of Cabbage Tree Bay” - people who have been involved in improving the protection of the Bay. The event attracted a high number of visitors and more than 200 submissions to the Draft Management Plan were made on the day, plus more electronically later. The stand-out result was “the great sense of belonging and community, etc ...”