Izumi Washitani is not only a professor of conservation ecology at the top-flight University of Tokyo, she's also a committed activist who applies her studies to restoring threatened biodiversity.

One of the threatened species she has researched is the so-called floating-heart plant (Nymphoides peltata) in Kasumigaura, Japan's second-biggest lake, which straddles Ibaraki and Chiba prefectures.

Washitani, 57, and her fellow scientists have monitored the plant for the Red Data Book compiled by the Environment Ministry. What they found, among many other things, was that in 1996 it covered some 99,497 sq. meters in the lake — but by 2000 it was down to 10,081 sq. meters.