Protect the Kakadu of the deep

Ninety per cent of the world’s oceans are unexplored and only a tiny 0.0001 per cent of the biology of the deep sea floor has been investigated, but the limited studies to date of these cold, deep, dark places find many wonderful surprises. Amazing new species, colourful luminescent life, cold water coral reefs 8,500 years old - 35m high, 40kms long and 3kms wide. Fantastical and beautiful.

Yet the mostly undiscovered worlds of the deep sea are already being destroyed by bottom trawling.

The most destructive type of fishing in the world, bottom trawling involves dragging huge nets armed with steel plates and heavy rollers across the seabed. The nets crush everything in their path, including ancient coral, and sweep up hundreds of bottom dwelling creatures along with the target fish species like orange roughy. The process is like clear-felling a forest.

Bottom trawling vessels are highly technological and operate on an industrial scale. Much bottom trawling takes place around seamounts - underwater mountains that rise 1,000 metres or higher from the seabed that are home to cold-water coral reefs and forests, sponge beds and hydrothermal vents.

Enormous quantities of plankton accumulate around seamounts, which in turn, attract a vast array of marine life. As feeding and spawning grounds for large marine mammals, including dolphins and whales, an extraordinary diversity of fish species and the birds that prey on them, exotic sponge ecosystems and microscopic bacteria, seamounts are among the world's greatest marine biological treasures.

The fragile deep-water ecosystems of seamounts and their coral systems are easily bulldozed by the heavy plates of bottom trawlers. In a few weeks bottom trawl fishing can reduce 1,000-year-old ecosystems to rubble. The possibility of re-generation is uncertain.

In short, bottom trawling is destroying our deep sea ecosystems, in many cases even before these wonderful deep sea worlds and their amazing deep sea creatures are discovered.

But the story need not be so bleak. In February 2004 over 1,000 marine scientists from 69 countries, including Australia, signed a statement asking the United Nations (UN) to halt bottom trawling in international waters.

Shortly afterwards the Deep Sea Conservation Coalition (DSCC) was established to aid the call for a moratorium on high seas bottom trawling. The DSCC wants to stop the current damage to allow time for scientists to assess and identify vulnerable areas of the deep ocean, and for the international community to implement governance measures for the sustainable management of the high seas. The DSCC is now an international alliance of over 50 primarily international organisations.

In November 2004 the UN recognised the problem and called on countries to “take action urgently to address the impact of destructive fishing practices, including bottom-trawling that has adverse impacts on vulnerable marine ecosystems, including seamounts, hydrothermal vents and cold water corals located beyond national jurisdiction”. It agreed to review the situation in 2006.

Unfortunately the recently released UN Review of “urgent actions” taken by nation states to address the impacts of bottom trawling found that “many fisheries are not managed until they are over-exploited and clearly depleted and, because of the high vulnerability of deep-sea species to exploitation and their low potential for recovery, this is of particular concern for these stocks. This raises the question of the urgent need for interim measures in particular circumstances, pending the adoption of conservation and management regimes”.

The United Nations has a chance to remedy this appalling situation - by agreeing a global ban on highly destructive fishing practices such as bottom trawling in all high seas areas at their next meeting in November.