Mining firm Nautilus Minerals is exploring high grade copper, zinc and gold deposits in the waters outside Papua New Guinea, while Neptune Minerals has prospecting licenses outside New Zealand, Papua New Guinea and Micronesia.

Nautilus has said its startup has been delayed three-to-six months after the collapse of a plan to have a vessel to ship the ore to shore built by Belgian dredging firm Jan de Nul.

"We have been building these things for 20 years," Noel Pille, director of the offshore department of Jan de Nul, said.

"Now they (Nautilus) will build it for the first time...I don't think they realise the details," he said.

He added that the rock Nautilus must cut into demanded some special equipment, which was viewed as being too expensive.

Nautilus's share price has been hard hit since the cancellation, down 40 percent to trade at 142.5 pence (US$2.89) per share as the project has lost time. But the company says it is still going ahead.

"We are saying that production could start in 2010 instead of the end of 2009," chief executive David Heydon at Nautilus said.

"The costs will change -- capital and operating costs -- all of that will come out by mid-October," he added.

THREE MONTHS DELAY

In New Zealand, severe weather has caused a three months setback of the exploration schedule for Neptune.

"We are three months behind because of bad weather that destroyed our equipment," CEO Simon McDonald said.

Equipment failure on the remote-operated vehicle used for sampling mineralisation delayed the assessment and definition of the mining zone until September, he said.

The firm's share price on London's Alternative Investment Market has risen to 36 pence, up by 12.5 percent since June.

TRIBAL OPPOSITION

Another problem the firms face is opposition from tribal communities living close to the exploration sites and some environmental experts are concerned about the impacts from seabed mining on the flora and fauna in the deep seas.

In Papua New Guinea, the Bagabag Community Development Association is concerned about environmental disturbance and damage, including water pollution, the group said in an email.

"As islanders, we depend for our entire livelihood for sea protein," the group's spokesman Paul Daing said.

Neptune targets inactive seafloor massive sulphide (SMS) deposits and these sulphide deposits support aquatic life, Cindy van Dover, Director of the Duke Marine Laboratory at Duke University in the United States.

"Until it can be demonstrated that there is no major loss of diversity or ecosystem service resulting from mining activities, the decision to permit commercial mining should be postponed," van Dover said in an email.

Both of the mining projects are located within territorial waters of the countries which have issued the prospecting licences. As a result, local laws, and not international conventions, apply.

"Nautilus appears to have been very responsible...but they really have only done environmental work just over the area where they want to mine," said Paul Tyler, Professor of Deepsea Biology at the University of Southampton in Britain.

Tyler said the dispersion of material could cause severe damage to flora and fauna in the area around the mining site.

Assistant Professor at the Department of Geology Jochen Halfar at the University of Toronto said if the first seabed mining project was successful more were likelty to follow.