Hope for Tuvalu in 'sand' that grows

The battle of rising sea levels versus the small Polynesian nation of Tuvalu may someday be won with natural building blocks that grow themselves.

Tuvalu's reef islands and atolls are under threat from rising sea levels triggered by global warming.

In a novel project, a team of Japanese researchers joined by Hajime Kayanne, a professor of coral reef studies at the University of Tokyo's School of Science, and the National Institute for Environmental Studies, aims to rescue the islets by taking advantage of the role of star sands, commonly found on beaches in Okinawa Prefecture, to form new land.

Atolls are formed by the accumulation of pieces of corals and seashells.

Star sands, just 1-2 millimeters in diameter, are a foraminifer, a species close to protozoa. They secrete their own calcareous shells and one star sand is believed to be capable of producing several hundred progeny.

According to research by the University of Tokyo, foraminifers accounted for 50 to 70 percent of the entire sediment of Tuvalu's atolls, a level higher than usual.

But the existence of foraminifers has noticeably diminished as a population surge in downtown areas has put strains on quality of nearby seawater.

The project involves breeding about 100,000 indigenous star sands and two other species of foraminifers ranging in size from 1 to 5 millimeters in four large tanks in Tuvalu.

The first challenge will be to determine the best conditions for mass propagation.

"If our project in Tuvalu proves successful, we want to make use of the technique in the Maldives and other island nations that are on the brink of being submerged," Kayanne said.