Deep lessons in ecosystem

RUSSIA is preparing to send two manned submarines to the bottom of the world's deepest lake in an attempt to learn more about its unique ecosystem, the expedition's organiser said.

The two small submersibles will descend more than one mile to the bottom of Lake Baikal, where they will conduct a host of geological and biological tests.

Lake Baikal is home to more than 1700 species of plants and animals.