ACCRA (Reuters) - Logging of a Ghanaian forest submerged 40 years ago by a hydroelectric dam could point to an underwater timber bonanza worth billions of dollars in tropical countries, a senior Ghanaian official said on Monday.

Exploiting submerged rot-resistant hardwoods such as ebony, wawa or odum trees in Lake Volta, the largest man-made lake in Africa, can also slow deforestation on land and curb emissions of greenhouse gases linked to burning of forests.

“Logging will start in October,” Robert Bamfo, head of Climate Change at the government’s Forestry Commission, told Reuters on the sidelines of a U.N. August 21-27 climate conference in Accra. “This will reduce the pressure on our forests.”

“The project aims to harvest 14 million cubic meters (494.4 million cu ft) of timber worth about $4 billion,” he said.

Logging will be led by a privately owned Canadian company, CSR Developments, which says it aims to invest $100 million in Ghana. Cutting equipment can be mounted on barges, guided by sonars to grab trees below water.

“There are very similar circumstances in numerous countries around the world including Ivory Coast, Cameroon, Brazil, Surinam, Malaysia and others,” Bamfo said of forgotten forests swamped by hydroelectric dams.

“The potential is there -- they are awaiting to see the outcome of the Ghana project,” he said.

He told the conference there were estimates that there were “5 million hectares (12.36 million acres) of salvageable submerged timber in the hydroelectric reservoirs in the tropics with the potential to supplement global demand for timber.”

“The trees are still strong,” Bamfo said, even though they had been under water since construction of the Akosombo Dam in the 1960s. Harvesting would cost more than on land but was still commercial because of the value of the timber.

BOAT COLLISIONS

In some shallower parts of the lake, covering an area of 850,000 hectares (2.1 million acres), thousands of trunks jut several meters out of the water. The lake is 90 meters (300 ft) deep at its deepest with a mean depth of 19 meters.

“Boat collisions with submerged tree stumps cause many fatalities every year,” Bamfo said.

In the 1960s, no one saw a need to fell the trees as the lake rose. “Maybe at the time we thought we had enough timber in our forest estates to sustain us. Now, because of the decline, we need to diversify.”

Ghana is being deforested at a rate of about 1.9 percent a year.

The U.N. conference is looking at ways to slow deforestation, blamed by U.N. surveys for emitting almost 20 percent of greenhouse gases from human activities. Trees soak up carbon dioxide as they grow and release it when burnt or when they rot.

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