It turns out, bird guano is amazingly rich with these sources of fixed nitrogen and phosphorus.

结果表明，鸟粪中含有相当丰富的固态氮和磷。

In the 19th century, settlers mined the island for bird guano, leaving the place mostly barren, hard coral.

19世纪，移民们在岛上开采鸟粪，留下了很多贫瘠坚硬的珊瑚。