The shipping industry, with its associated substantial infrastructure (ports, harbours, shipping lanes, coastal support), is the major transportation link between Australia and other nations, and provides important linkages between regional Australia and the cities. Ports and shipping are a key component of the economic activity of Australia, with 99% by weight and 74% by value of our international trade carried by sea. Seventy commercial ports around the Australian coast deal with international shipping, and there are hundreds more smaller facilities providing critical infrastructure for a range of activities. In 2008–09, approximately 800 million tonnes of cargo were moved through Australian wharves by 4200 vessels that made 26 700 port calls.57 In 2002, more than 3000 foreign commercial ships made more than 18 000 separate calls at Australian ports.2-4 In Dampier (Western Australia) alone, in 2006, there were more than 3000 vessel visits, mostly from overseas ports, and these vessels discharged 42 million tonnes of water.58
The continuing development of regional Australia is resulting in many new ports and expanding and upgrading of existing ports. To service these developments, there is always a backdrop of coastal infrastructure, some of which is new, creating further demand on coastal land and recreational facilities in marine systems. Many of these new and upgraded facilities are developing to support the growing mining industry in Queensland, the Northern Territory and Western Australia.
Shipping lanes traverse some of the most ecologically sensitive marine areas, and regular groundings and accidents at sea place additional pressure on the marine environment. Also of increasing concern is the frequency of ship strikes on marine mammals, many of which occur in open waters and pass unreported.
The increase in shipping traffic is also increasing the risk of introductions of foreign marine species, and there is a risk that some of these will turn into serious pests in our waters. Many hundreds of introduced marine plants and animals have already hitchhiked to Australian waters on vessels of all types, from yachts to commercial ships, carried on their hulls and in ballast waters (water carried in tanks to maintain stability when a ship is lightly loaded). Some of these species have taken over habitats from our native species, changing our coastal areas and damaging our fishing, aquaculture and tourism industries.
Once marine pests are established, eliminating them is virtually impossible. Where conditions suit, they may multiply quickly and force out native species. Some (such as toxic algae) can pose a threat to human health as well as ecological health. The Australian, state and territory governments, along with marine industries and marine scientists, are implementing a National System for the Prevention and Management of Marine Pest Incursions to identify and respond to marine pests. This system aims to prevent new pests arriving, respond if a new pest does arrive, and minimise the spread and impact of pests that are already established in Australia. The system accepts that, where they have become established, marine pests will not be able to be eradicated, so ongoing management and control of introduced marine pests will be required.59