The SA coast is important for its unique biodiversity and high socio-economic values. The wide range of coastal landforms and marine habitats with biological richness and unique plants and animals have been shaped by millions of years of geological isolation, an extensive continental shelf, an exceptionally long east–west extent and low-nutrient waters.
Important features of the SA coast are 2 large tidal gulf ecosystems (Gulf St Vincent and Spencer Gulf), temperate inverse estuaries with warm, progressively hypersaline waters and a high degree of variability in sea temperatures. They shelter large areas of temperate mangrove, seagrass and tidal saltmarsh.
Periodic wind driven upwellings of cool nutrient-rich waters into coastal regions on the west coast and the southeast drive marine productivity and support numerous fisheries, particularly through the largely unspoiled Great Australian Bight.
South Australia’s coastal natural assets include estuaries, wetlands, reefs, cliffs, rocky shores, sand dunes, sandy beaches, mudflats, saltmarshes, mangroves, seagrasses and macroalgae. These provide habitat for invertebrates, fish, reptiles, birds and mammals. Many of these natural assets are afforded formal protection in the network of marine parks and reported on in a series of trend and condition reports.
The 2013 SOER provided condition assessments of key environmental assets for each of the 8 bioregions. These form part of the EPA’s comprehensive aquatic ecosystem condition assessments that encompass all of the state. Each assessment provides a physical description of the particular section of coast, assesses its current condition, identify key pressures, and explain the management actions undertaken in response.
A 1998 report, Conserving Marine Biodiversity in South Australia – Part 1 – Background, Status and Review of Approach to Marine Biodiversity Conservation in South Australia, provided the first comprehensive description of SA’s marine biodiversity.
The SA Government’s 2017 marine parks status report, which consolidates detailed baseline reports for the 19 marine parks in SA, provides more recent evidence of the environmental and socio-economic values of the SA marine environment.
The SA Government has prepared coastal conservation assessments for the mainland coastal areas extending from the low-water mark to the inland extent of coastal features. These assessments consolidate existing information about the conservation values and threats for coastal areas providing a baseline to update in future as necessary.
Socio-economic value of the coast
In addition to its critical role in supporting rich biological diversity, the coast is also of important social and economic value.
While conservation and economic values are interdependent, they can be in conflict, for example, coastal development and its impacts on seagrasses in the form of runoff. Adequately understanding the links between ecosystems and societal and economic values can help our understanding of potential tradeoffs considered in planning and policy decisions, improving transparency and equity in decision making.
For example, an estimate of the increased juvenile fish numbers resulting from restoring seagrass habitats showed a strong positive return on investment in seagrass restoration efforts. Another study measuring willingness of Adelaide households to pay for improved water quality found that restoring 25 days per year of water clarity, increasing seagrass area from 60% to 70% of the original area and restoring 5 reef areas were considered to be worth $67.1 million to households.
A number of SA businesses, industries and jobs are either reliant on the ecological values of the coast or use the coast. This includes tourism, shipping, aquaculture and fishing. The coastline harbours significant cultural and Aboriginal heritage, and Aboriginal communities have a strong spiritual connection to the coast and its natural resources.
Proximity to the coast generally has a positive impact on property values and opportunities for employment, tourism and recreation. More than 5 million people visit SA coastal areas annually from interstate and overseas. Other socio-economic benefits of the coast include transport and infrastructure, aquaculture, recreational fishing and commercial fishing.
South Australia’s total seafood production, including flow on economic impacts, was valued at more than $1,547 million a year in 2016–17, of which aquaculture contributes about 40% and wild-catch fisheries 60%. Tuna makes up half of the aquaculture share and also provides tourism opportunities such as swimming with tuna.
Southern Rock Lobster makes up approximately one-third of the fisheries share. The SA fishing and aquaculture industries support an estimated 6,059 jobs with the majority of these in regional SA. South Australia’s fishery and aquaculture production made up 17% of the gross value of Australia’s total production value from these sectors in 2015–16.
As far back as 1996, the State of the Marine Environment Report for Australia estimated the economic value of coastal and marine tourism, fisheries, marine transport and offshore petroleum to be worth about $17 billion per year. The capitalised value of goods and services of coastal ecosystems was also assessed in a subsequent research paper as equalling or exceeding the total value of the assets of the Australian market economy. The annual environmental goods and services from coastal assets were also estimated to exceed the value of Australia’s GDP.