guano

CNNが簡単な歴史をまとめています。

guanoは 「鳥糞石、人工肥料」（"a fertilizer containing the accumulated excrement of seabirds or batst"--Webster）で、燐酸肥料に利用されるとのことです。（UG）

One question hanging over territorial claims is whether the disputed islands are islands at all, according to maritime law. If they're not islands, then territorial claims don't apply.

Both sides say they have a history of economic use of the islands. China points to a 1893 decree by Dowager Empress Cixi, giving the island to a Chinese medicine-maker for use in cultivating herbs. Japan points to 19th-century use on the island to collect seabird feathers and guano.

Tokyo Gov. Shintaro Ishihara says a Japanese family claims to own four of the five disputed islands, and that it has documents showing the islands' Japanese ownership dating to 1890.

http://edition.cnn.com/2012/08/19/world/asia/japan-china-island-dispute/index.html?hpt=ias_c1