South Australia’s marine environment is unique. It has more diversity than the Great Barrier Reef, and about 85% of the organisms found there are found nowhere else (DEWNR 2013). Ocean upwellings, which bring nutrients to the surface, and deep canyons are important contributors to the biodiversity in this region (Nieblas et al 2009, Schmidt et al 2010, van Ruth 2010). There are also more than 100 offshore islands which are valuable conservation areas (Robinson et al 1996).
Some parts of South Australia’s marine ecosystem are stable and in good condition, but other parts are in poor condition and getting worse. This is partly due to pressure from fishing, aquaculture, shipping, and mining – all of which have management practices which could be improved (Government of South Australia 2012).
South Australia’s marine ecosystems have a high level of biodiversity. There are a number of reasons for this, including generally low nutrient levels and sixty five million years of geographical isolation. The coast of South Australia is made up of several different zones – including the Great Australian Bight, Spencer Gulf, Gulf St Vincent, the south east coast, and about 150 offshore islands. Most parts of the coast feature sandy beaches or rocky shores, which receive the full force of the Southern Ocean waves, but parts of the gulf regions host mudflats, seagrass beds, and mangroves (Lewis et al 1998).
Deep ocean upwellings bring nutrients to the surface along the Bonney Coast and south west of Kangaroo Island, contributing to high productivity in those regions. The deep sea Murray Canyons, thought to have been created by the ancient course of the Murray River, before sea levels rose, are also hotspots of biological activity. The mangroves, seagrass meadows, and mudflats of the gulfs and other areas of coast are highly productive and very important to South Australia’s fisheries industry (Lewis et al 1998, Nieblas et al 2009, Schmidt et al 2010, van Ruth 2010).
There are about 150 offshore islands in South Australian waters, all of which are valuable conservation areas, and most of which are either national parks of conservation parks. Some of those islands have not had a human presence for at least fifteen thousand years and are probably the least disturbed areas in the state – making them extremely significant in conservation terms (Robinson et al 1996).
Approximately 90% of the marine animal species in South Australian waters are endemic and only about 40% of the invertebrates have so far been described. South Australian waters are home to the world’s richest assemblage of sea squirts, the smallest starfish, the largest crab, one of the largest octopuses, one of the largest cuttlefish, and over 500 species of nudibranch (Lewis et al 1998).
Over 370 species of marine fish have been recorded, a number of which are rare or endangered – including South Australia’s emblem animal, the leafy sea dragon. There are 31 species of marine mammals, including some which are rare or endangered. Several whale species also inhabit South Australian waters, including the endangered southern right whale (Lewis et al 1998, Director of National Parks 2005).
Birds are also an important part of South Australia’s marine ecosystems. There are over a hundred sea and shore bird species either resident or visiting, including about thirty species which breed there (Lewis et al 1998).
Almost the entire population of South Australia lives within 50 km of the coast. Development and industry have had, and continue to have, significant detrimental effects on the marine environment. Of these industries, fisheries, aquaculture, mining, and tourism, along with urban development, have the greatest effect (Leadbeter 1996, Harvey & Caton 2010, von Baumgarten 2014).
Declining fish stocks due to overfishing has long been a concern. This can also be brought about by clearance of mangroves and seagrass beds, as well as by pollution. Other effects of fishing include changes to the sea bed and benthic habitats caused by trawling, changes in the composition of fish communities, waste and marine debris, and loss of non-targeted species in by-catch. By-catch can also be a threat to endangered species (Harvey & Caton 2010).
Tourism is economically important and provides a high proportion of jobs in coastal towns. However, its effects on the marine environment are significant. These effects include habitat loss due to badly planned development, as well as erosion and damage to coastal vegetation caused by off road vehicles and camping. Plant and animal populations can be adversely affected by disturbance and destruction of habitat, as well as by introduction of alien species (Harvey & Caton 2010).
Aquaculture generates waste which can produce algal blooms, it can change habitats, sediments, and water quality, and put pressure on species of fish used for food. Mining can cause coastal erosion and loss of wilderness areas, create noise and dust, affect coastal waters with fuel or oil spills, and lead to introduction of species and diseases. Even small coastal developments can have a rapid effect on ecosystems – the main effects are habitat destruction, erosion, sediment runoff, and the introduction of invasive species (Harvey & Caton 2010).
Managing the ocean and coastal areas to prevent the problems caused by these environmental pressures is complex and challenging, but it is essential if we are to avoid continued degradation of those ecosystems. Integrated coastal and ocean management (ICOM) attempts to unite governments, industries, and the community to ensure sustainable use of marine resources (Harvey & Morcom 2002, Foster et al 2005). The focus of this approach should be on managing human activities which affect ecosystems, rather than managing the ecosystems themselves (Harvey & Caton 2010).
Australia’s Oceans Policy (AOP) put Australia at the forefront of integrated oceans management in 1998. AOP featured regional marine plans and integrated ecosystem based management, taking into account multiple uses of the marine environment. However, although the policy has had some success, attempts at integrating marine management seem to have largely failed (Foster et al 2005, Vince 2013).
South Australia’s Marine Parks Act 2007 incorporates the principles of ecologically sustainable development and attempts to “integrate both long term and short term economic, environmental, social and equity considerations” to protect and preserve a comprehensive, adequate, and representative network of marine ecosystems (Government of South Australia 2007). However, implementing marine parks in South Australia has met with a certain amount of opposition from commercial and recreational fishers (Novak 2014).
While state and federal government policy initiatives in the field of ICOM have improved considerably on management systems which preceded them, funding is required for research, monitoring, and compliance. However, in the current political and economic climate, sufficient funding is not always available (von Baumgarten 2014).
South Australia’s coastal and ocean ecosystems are spectacular and globally unique. However, the demands of industry and urban development are placing them under increasing environmental pressure. World leading coastal and ocean management policies have been implemented in Australia, but there is not always sufficient funding available for them to achieve their maximum potential.
DEWNR 2013, Marine park science, Department of Environment, Water and Natural Resources, Adelaide, SA. Retrieved from http://www.environment.sa.gov.au/marineparks/Learn/Marine_park_science on 15/9/14.
Director of National Parks 2005, Great Australian Bight Marine Park (Commonwealth Waters) Managment Plan 2005 – 2012, Australian Government, Canberra, ACT.
Foster, E, Haward, M, and Coffen-Smout, S 2005, ‘Implementing integrated oceans management: Australia’s south east regional marine plan (SERMP) and Canada’s eastern Scotian shelf integrated management (ESSIM) initiative’, Marine Policy, 29, 5, 391-405.
Government of South Australia 2007, Marine Parks Act 2007, Australasian Legal Information Institute, Sydney, NSW. Retrieved from http://www.austlii.edu.au/au/legis/sa/consol_act/mpa2007135 on 22/9/14.
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Lewis RK, Edyvane KS, and Newland N 1998, The state of Our Seas and Coasts, Government of South Australia, Adelaide, SA.
Nieblas, AE, Sloyan, BM, Hobday, AJ, Coleman, R, & Richardson, AJ 2009, ‘Variability of biological production in low wind-forced regional upwelling systems: A case study off south eastern Australia’, Limnology and Oceanography, 54, 5, 1548-1558.
Novak, L 2014, ‘Opposition MP Michelle Lensink introduces legislation to downgrade fishing restrictions in South Australia marine parks’, The Advertiser, June 18 2014.
Robinson, T, Canty, P, Mooney, T, and Rudduck, P 1996, South Australia’s Offshore Islands, Australian Heritage Commission, Canberra, ACT.
Schmidt, S, de Deckker, P, Etcheber, H, and Caradec, S 2010, ‘Are the Murray Canyons offshore southern Australia still active for sediment transport?’, in P Bishop and B Pillans (eds) Australian Landscapes, Geological Society, London, UK.
van Ruth, PD, Ganf, GG, and Ward, TM 2010, ‘Hot-spots of primary productivity: an alternative interpretation to conventional upwelling models’, Estuarine, Coastal and Shelf Science, 90, 3, 142-158.
Vince, J 2013, ‘Marine bioregional plans and implementation issues: Australia’s oceans policy process’, Marine Policy, 38, 325-329.
von Baumgarten, P 2014, ‘Assessing, regulating and managing coastal environments for production, conservation and amenity’, seminar presented at the University of Adelaide, 10th September 2014.