The argument has now relocated to Abbot Point near the town of Bowen. The tone of this debate has sharpened markedly since mining companies’ recent attempts to open up the Queensland coast to coal exports.ĭredging at Gladstone harbour has been extremely controversial, with critics claiming that a rushed, botched process saw sediment spill across the ecosystem, causing fish and crabs to develop lesions and die.Ĭonservationists and recreational fishers have blamed dredging for killing fish at Gladstone, although a government report blamed floods, rather than dredging, for washing harmful nutrients into the area.

Some activists want dredging to be banned completely, blaming it for releasing toxic chemicals, increasing water turbidity and littering harmful metals throughout the food chain. The federal government requires dredging companies to obtain a permit to dump sediment, stating that fragile areas need “a high level of protection and/or management”.ĭespite the regulatory framework around dredging, environmentalists claim oversight has been lax, causing damage to marine creatures. Sediment can smother seagrasses, which are the key food source of dugongs and sea turtles, and damage corals. Removing large parts of the seabed and dumping it elsewhere can have a major impact on the ecosystem, particularly sensitive areas such as coral reefs and fish nurseries. The coal, extracted from the Galilee Basin in central Queensland, will be sold to overseas markets such as China and India. Greg Hunt, the environment minister, has approved dredging for three new port terminals, to be operated by a selection of Indian and Australian mining companies.Ī total of 3m cubic metres of seabed will be removed to allow vessels to access Abbot Point, with up to 300m tonnes of coal shipped annually by 2020. In the case of Abbot Point, dredging will be used to expand what is essentially a simple jetty jutting out into the sea into one of the world’s largest coal ports. The debris collected is usually a mixture of sand, mud and rock.

Sometimes the sediment from dredging is used to “renourish” onshore areas, such as coastal areas subject to erosion.

Large vessels require water of a certain depth to access these routes, so dredging is used to ensure they don’t run aground. Various Australian waters have been dredged in the past, most notably Port Phillip Bay, overlooked by Melbourne, and, more recently, locations off the Queensland coast such as Gladstone harbour.ĭredging is mainly used to either maintain the depth of ports or create new shipping channels.

Dredge mining pros and cons