The Port Noarlunga Reef and Onkaparinga Estuary Aquatic Reserve is South Australia's most intensively-used and best known Aquatic Reserve, with an estimated 170 000 visitors each year, conducting a wide range of aquatic activities, including SCUBA diving, snorkelling, boating, swimming and recreational fishing. In particular, Port Noarlunga Reef provides a major focus for snorkelling activities and SCUBA diving training in South Australia, with regular summer aquatic education classes conducted by the Port Noarlunga Aquatic Centre (Department of Education), and an estimated 6000 SCUBA divers visiting the reef each summer.
Established in 1971 to specifically protect the reef life and adjacent river estuary, the Port Noarlunga Reef and Onkaparinga Estuary Aquatic Reserve provides a range of estuarine and marine habitats. The wide range of activities conducted within the reserve, and the high level of accessibility, however have led to considerable conflicts between user groups, particularly snorkellers/SCUBA divers and recreational fishers. There is also evidence that high visitor use may be having significant impacts on the marine life of the reef. Despite this very high level of aquatic activity however, many visitors remain unaware of the reserve status of the area, particularly the regulations and the natural features of the reserve, and importantly, the role of Aquatic Reserves in protecting and managing marine environments.
In 1993 the South Australian Research and Development Institute (SARDI) received Commonwealth funding under the national `Ocean Rescue 2000' Marine Protected Areas Program to establish an underwater interpretation trail at Port Noarlunga Reef, specifically to raise community awareness of the Aquatic Reserves and the need to protect the marine environment. This proposal developed out of a feasibility study conducted by John Papple (University of South Australia), commissioned by the former SA Department of Fisheries, which identified Port Noarlunga Reef as an ideal site for establishing a underwater marine interpretation trail and increasing the community's awareness of the marine environment.
As recommended in the feasibility study, the development and establishment of the underwater trail was overseen by a Consultative Committee, convened by the SARDI (Aquatic Sciences) and comprised representatives from government and local community stakeholders groups, including the Port Noarlunga Primary School and Aquatic Centre, Noarlunga Council, Tourism SA, Southern Diving Centre and the Adelaide Skindiving Club.
Establishment of the trail involved the design, construction and establishment of 12 underwater trail markers (with interpretative plaques), and shore-based signage and pamphlets on the underwater trail and the Port Noarlunga Reef and Onkaparinga Estuary Aquatic Reserve. Fisheries regulation changes within the Aquatic Reserve were necessary to reduce conflict between snorkellers/ SCUBA divers using the trail and recreational fishers, and also, to reduce public legal liability. As such, existing regulations within the reserve permitted line fishing immediately adjacent to the proposed site of the underwater trail. Changes to the fishing regulations in the reserve were achieved through formal consultation with recreational and commercial fishing interests and resulted in the extension of the `non-fishing’ areas on North Reef from, within 25m to 100m of reef. The boundaries of the reserve were also extended to include the adjacent limestone reef of Horseshoe Reef.
The establishment of an underwater interpretation trail at Port Noarlunga Reef represents the first underwater marine education trail in South Australia. As such, the trail represents a major marine education and interpretation initiative in South Australia, which both, promotes community awareness and understanding of the marine environment and also, the important role of Aquatic Reserves in protecting and managing marine ecosystems.
A report summarising both the technical, planning and administrative processes that were followed to establish South Australia's first underwater marine interpretation trail, and also, outlining a framework for addressing future monitoring and management needs and responsibilities is available from SARDI.