Module 1

 Module 1 Home

The Nature, Purpose and Scope
of Coastal and Marine Studies

Reading 1 The Coastal and Marine Environment

Reading 2 An Overview of Coastal Ecosystems and Their Values





Reading 1

The Coastal and Marine Environment

Source: Adapted from Our Sea, Our Future: Major Findings of the State of the Marine Environment Report for Australia, Department of the Environment, Sport and Territories, Canberra, 1995; and Cocks, K.D. and Crossland, C. (1991) The Australian Coastal Zone: A Discussion Paper, Resource Allocation Program, Division of Wildlife and Ecology, CSIRO, Canberra.


Australian waters span almost 60 degrees of latitude from Torres Strait to Antarctica, and 72 degrees of longitude from Norfolk Island to the Cocos Islands (OHT 4). They include a great range of geographic, geological and oceanographic features. Australia's marine environment extends from the shores and wetlands along the coastline to the ocean depths, and from tropical coral reefs to antarctic packice. Coastal and marine environments are under increasing pressure from human activities in the marine, coastal and terrestrial environments (OHT 5).

The Coastal Zone

The coastal zone comprises components of land (catchments, wetlands, dune systems) and the sea (intertidal and subtidal regions of the continental shelf) (see Figure 1, OHT 6). Biologically, the coastal zone extends to the edge of the continental shelf. Legally, there are prescribed limits of responsibility determined by the Commonwealth and State authorities. Under international law, Australia is entitled to a 12 nautical mile territorial sea. Beyond territorial waters is the Australian Fishing Zone extending 200 nautical miles seaward and encompassing an area of about 3 million square kilometres. Because each State and Territory has title to the seabed of the territorial sea adjacent to it,

Australia's coastal zone lacks a unified definition and some sections are subject to many legislative instruments and regulations (OHT 7). For the purpose of the actions of the Commonwealth, the boundaries of the coastal zone are considered to extend as far inland and as far seaward as necessary to achieve its coastal policy objectives, with a primary focus on the land-sea interface. Thus any discussion of coastal matters must focus on the shoreline, coastal waters and islands, estuaries and other tidal waters, coastal wetlands and land adjacent to these features. Australia's coastal zone supports most of the nation's population and much of its economic and social activity. Therefore, sound management of the coastal zone is of profound importance to the maintenance of many of Australia's important ecological systems as well as to the socio-economic development of the nation. The challenge is to manage the use of the coast in such a way that undesirable impacts are eliminated, or, at least, minimised.

Coastal and Marine Ecosystems

Estuaries are meeting places of fresh and salt waters. They are naturally rich in nutrients, ecologically highly productive and important fish habitats. Australian estuaries have been the focus of urban and industrial development and are important for recreation. Australia has 783 major estuaries. Clearing of river catchments in eastern and southern Australia has resulted in land erosion, sedimentation of rivers and increased sediment and nutrient levels in estuaries and adjacent coastal waters. Sedimentation is a major problem in ports and shipping channels. The flows of many of Australia's rivers have been significantly altered by dams, barriers, land reclamation schemes and flood mitigation schemes. These changes affect the hydrodynamics and flushing characteristics of estuaries. Of estuaries that have been studied, 64% in New South Wales and 22% in Victoria are considered to have poor water quality.

Coastlines and shore communities
are the meeting place of land and sea. Australian shores include open coasts, rocky headlands, sandy beaches, and muddy and sandy tidal flats. Shores have a high diversity of specialised plants and animals. Shores are also the social gathering places for people. Beaches are the most popular areas for outdoor recreation in Australia. Threats to shore communities include over-harvesting of molluscs, crustaceans and sea urchins for food and bait, trampling, oil slicks and loss of habitat. In more populous areas urban development has placed significant pressures on shore communities. Shores are not usually well protected because management of intertidal areas is confused by overlapping responsibilities and lack of coordination.

are intertidal plant communities dominated by herbs and low shrubs. They are highly productive, key habitats that support many organisms. They are also a critical habitat for migratory birds such as the Orange-bellied Parrot. A major threat to saltmarshes in developed areas is land reclamation for ports, marinas, canal estates, urban development and industrial sites. Other threats include degradation by rubbish dumping, off-road vehicles, and invasion by weeds.

are tree and shrub species that are adapted to periodically inundation and salty conditions between tides. Mangrove forests are very productive ecosystems and are of major ecological and economic importance. They provide habitats that encompass nurseries for many fish species, form buffer zones from sediments and storm waves, are natural nutrient filters and are critical habitats for many birds and other wildlife. Significant losses of mangrove habitats have occurred around coastal cities.

Seagrass beds are ecologically important because of their high productivity, ability to trap sediments, importance as fish, dugong and turtles habitats. Australia has the highest diversity of seagrasses in the world. Australia's unique temperate grasses appear to be under particular threat from increased sedimentation and nutrient levels. The decline in temperate seagrasses is one of the most serious issues in the marine environment.

Reefs are important because of their high biodiversity and importance for recreational and commercial fishing. Around 80%-90% of the flora and fauna of Australia's temperate reefs are endemic. Australia has the largest area of coral reefs of any nation and the largest coral complex (The Great Barrier Reef). General issues affecting reefs include increased nutrient and sediment levels, tourism and recreation, fishing and the real threat of oil spills.

Coastal and Marine Studies

Many factors influence people's values (family, friends, media and personal experience) but it is education at schools, colleges and universities that gives people most of the formal knowledge and skills to make informed decisions and the ability to act on them. During their formal education every Australian student learns something about the sea in a variety of subjects from art to zoology.

The sustainability of coastal and marine systems also depends on Australians knowing about the marine environment, recognising the threats to it, wanting to care for it, and learning the skills to look after it. Therefore, coastal and marine studies are also vital for achieving the environmental awareness, values attitudes, and skills consistent with ecologically sustainable development. To this end, a long-term national coastal and marine education programme has been introduced to help develop:

  • an awareness, appreciation and understanding of the marine environment and of the need for its conservation;

  • environmentally responsible attitudes;

  • a commitment to work for a change that would promote the conservation of the coastal and marine environment;

  • a wide range of skills for successfully tackling coastal environmental problems;

  • the ability to actively contribute to planning and management processes; and

  • a high level of commitment to future management programs.