I don't know how to review this book and do it justice, but it's a wonderful, beautiful and extremely saddening read. If everyone could just read it, and if it could be compulsory reading in schools, maybe we might just learn something and be better custodians of the planet.
It's superbly written, and if you've any heart at all it will stay with you for a very long time. Clarke's understanding, and descriptions, of the the natural processes all living things go through, their irresistible drives, their delicate and critical inter-dependencies (and heartbreakingly how easily, carelessly and ignorantly they're all destroyed by man's parallel activities) are wonderfully and beautifully brought to the page. He avoids sentimentality or mawkishness, he doesn't take a side, he simply writes about what goes on in one fictional stream - and he writes it in such a way that you are drawn in and spellbound.
It's a short book, but with massive impact. Both a joy and a sadness to read. If you can read it and be the same person at the end that you were at the beginning, you have no heart or soul.
Read this book. Pass it on. Recommend it.