Coastal management

Introduction

In comparison with many countries of the world, Australia possesses an enormous continuous coastline. Including islands, Australia's coast stretches for about 60 000 kilometres and comprises over 10 000 separate beaches. About two-thirds of the population live in the towns and cities that have been built to take advantage of the many benefits the coastline brings. Coastal management refers to the use and protection of this vast area, which is made up of marine (saltwater) and estuarine (meeting point of fresh and saltwater) ecosystems. In a constant state of evolution, these areas are naturally affected by rainfall, wind, ocean currents, waves and tidal movements.

Key human impacts and resultant environmental issues

Our coastal zone houses great potential in terms of its use for commercial, recreational and settlement purposes. It also holds many social and cultural values for both Indigenous and non-Indigenous Australians alike. Sadly, human use and enjoyment of the coast over the past two centuries have greatly disrupted the processes which form its intricate ecosystems.

Human activities have also reduced the biodiversity of our coastlines, which helps them to maintain their health. Small organisms in coastal ecosystems are often the first link in large food chains. The impact of their population reduction or extinction inevitably reverberates throughout the entire chain. The most significant ways in which humans have impacted upon Australia's coastline are outlined below.

Housing and development

The construction of houses around lagoons and swamps, the use of wetlands for landfills and the development of sand dunes for 'prime' real estate and recreational purposes have all had negative effects on Australia's coastal areas. The removal of vegetation has seen a significant reduction in biodiversity and also disrupted the natural processes which form intricate coastal ecosystems. See image 1

Ports and marinas

In order to enhance the navigational potential of our coastline, natural channels are often widened or deepened by removing earth from the bottom of waterways (a process known as dredging). This destroys the habitats of benthic (bottom-dwelling) organisms that live in the sediment that is removed. Stone breakwaters stretching far out to sea are also constructed around ports and marinas to reduce the impact of waves and tidal fluctuations. This has the negative consequence of hindering natural erosion and mineral deposition processes, similar to those described above.

Stormwater run-off and pollution

Vast areas of land covered in concrete and bitumen, particularly in large cities, generate an enormous amount of contaminated stormwater and rainwater run-off. This pollutes our waterways and damages fragile coastal ecosystems. Added to these contaminants are petroleum-related pollutants emitted from motorboats, ferries and large ships, which account for about 20-30 per cent per cent of all marine pollution.

Sand mining

In some parts of Australia particularly Queensland, northern New South Wales, parts of Western Australia and South Australia, certain minerals found in beach sand are mined for the production of paints and industrial tools. These sand minerals include zircon, ilmenite and rutile. In some areas of WA, calcareous sand beneath seabeds is also mined for the production of limestone and cement. Australia has the world's largest Economic Demonstrated Resource (EDR) of these mineral sands and they are an important source of export earnings. Their extraction, however, requires the quarrying of beaches, which disrupts the natural cycles that form sand banks and destroys the habitats of many plants and animals.

Recreation and tourism

Australians have also utilised the coastline for recreational and tourism purposes. The construction of high-rise resorts, shopping esplanades, playgrounds, golf courses and beach car parks are a few common examples. While this development has undoubtedly enhanced the lifestyles of residents and the holiday experiences of domestic and overseas tourists, it has caused significant damage to Australia's precious coastal areas. Even in less-frequented areas, the use of sand dunes for recreational purposes (the now popularised four-wheel driving a prime example) damages sand dune formation and scares away wildlife. See animation 1

Sustainable coastal management

The protection of Australia's coastline depends on our capacity to implement sustainable coastal management initiatives. This will need to include such considerations as balancing competing uses of the coast, increasing the amount of protected marine and estuarine reserves, restricting further development in coastal areas and conducting research into making the most of coastal areas in an ecologically sustainable manner.

One factor which has hindered the protection of Australia's coastline in the past has been a lack of tight regulations placed on private sector developers. Another is that different levels of government in Australia manage separate areas of the coastline. Broadly speaking, responsibility for the coastline within three nautical miles (nm) of the shore rests with the local, State and Territory governments. The federal government is responsible for the management of waters for 200 nm beyond this. This division of powers can complicate matters because the environmental impacts of activities undertaken in coastal zones do not follow this jurisdictional division.

On a positive note, in 2003 the federal government endorsed the 'Framework for a National Cooperative Approach to Integrated Coastal Zone Management'. This initiative has been a key milestone in addressing the need for coordinated efforts and tighter monitoring of development in the area of coastal management.