QINGDAO - Chinese scientists will begin testing the country's self-developed underwater gliders and autonomous unmanned submersible in yet another maritime scientific expedition.

The equipment -- 12 gliders, one submersible, and a Raman spectrometer -- was loaded on the research vessel "Kexue" (Science), which left Qingdao in east Shandong Province Monday.

The program's lead scientist Sun Song said such devices demonstrate China's strong maritime research capability.

Sun said scientists would use the equipment in research of deep-water cold seeps in the South China Sea.

Cold seeps are located at the sea floor where hydrocarbon-rich fluid seepage occurs. Sun said the whole ecosystems at the cold seeps, where sunlight can not reach, is supported by hydrocarbons.

A deeper research into the cold seeps may reveal the secrets of the evolution of life on Earth, which could trace to the earliest ecosystems formed by microorganisms, Sun said.

From the South China Sea, the research ship will sail to Yap Trench for marine organism and ecology survey. It is scheduled to return to Qingdao in late September.