Long spared because of their remoteness, the high seas have become an important hunting ground for fish trawlers and oil prospectors, putting at risk many marine species that call these waters home.

Covering 64 percent of the oceans and half the Earth's surface, international waters have become the next frontier as fish stocks nearer to the coast run out and oil exploration ships are spurred on by high fuel prices.

The high seas, where no national laws apply and international rules are often vague, have become a "lawless zone" where prospectors operate "on a first-come-first-served" basis, oceanographic and marine law experts lamented at a conference in Monaco last week.

Policy makers from 184 countries meeting in Hyderabad, India until Friday in a bid to turn around the rate of biodiversity loss, will also examine ways to prevent the international waters becoming a deep-sea Wild West.

"International waters and seabeds are a vital part of the global ocean and planetary life support system, producing much of the oxygen and storing both CO2 and heat, (making) life on Earth habitable for us humans," Kristina Gjerde, of the International Union for Conservation of Nature, told AFP.

"They are also of vast importance for supporting a wide range of marine life, from tiny phytoplankton to blue whales, the largest creatures on our planet."

The threats are diverse.

With little supervision, trawlers are indiscriminately scooping up unsustainable numbers of fish, permanently harming species populations and damaging the ocean floor.

Alongside oil prospecting ships, they also cause chemical and sound pollution, disrupting species such as whales and dolphins that rely on sonar communication for socialising, hunting and mating.

In anticipation of global rules being adopted to better manage the exploitation of deep-sea resources, an issue discussed at length but without resolution at the Rio+20 environment summit in June, hopes are that the UN Convention on Biodiversity meeting in India will adopt some safeguards.

Officials, joined from Wednesday also by environmental ministers from more than 70 countries, were set to examine the findings of scientific reports that have identified more than 120 marine biodiversity "hot spots".

The reports were compiled by regional study groups examining all the world's oceans and measuring different indicators of species vulnerability.

"It is above all a scientific exercise aimed at cataloguing the zones to be protected," said Elisabeth Druel, marine law expert at the Institute for Sustainable Development and International Relations.

Adoption of the scientific reports would mark "a small procedural step, but a big one politically", added Jean-Patrick Le Duc, a member of the French delegation negotiating in Hyderabad.

"It will send a strong signal" in favour of the creation of protected marine areas on the high seas, which now enjoy little protection.

The global objective, adopted at the last CBD conference in Japan two years ago, is to have 10 percent of marine and coastal areas under conservation by 2020 -- up from two percent today.

At Hyderabad, certain countries, notably those with big fishing fleets such as Japan, Norway, Iceland and Greece, are not keen to see constraints imposed, observers have noted.

Daniela Diz, responsible for marine policy at green group WWF, said endorsement of the scientific reports was a necessary first step to the UN General Assembly finally approving the creation of deep-see protected areas.

"The point is that if the reports are not endorsed they won't be included in the repository or sent to relevant organisations, which means that all that fantastic scientific information produced in the workshops would be lost."