Danau Baikal

Polly terbangun pada pagi kelima dan dunia telah menjadi air.

Polly woke up on the fifth morning and the world had become water.

Kereta api itu melaju di sepanjang pantai selatan Danau Baikal. Danau itu memenuhi seluruh jendela: bukan sekadar danau, lebih seperti laut, kecuali ketenangan sempurna dan kejernihan warna yang mustahil, biru yang tampaknya dimulai dari jauh di bawah permukaan dan naik ke atas.

The train was running along the southern shore of Lake Baikal. The lake filled the entire window: not a lake so much as a sea, except for the perfect stillness and the impossible clarity of the colour, which was a blue that seemed to start somewhere deep below the surface and rise up.

Igor, si nelayan, sudah bangun selama dua jam. Dia berada di jendela dengan buku catatan kecil.

Igor, the fisherman, had been awake for two hours. He was at the window with a small notebook.

"Baikal," katanya. "Ini adalah danau terdalam di dunia. Seribu enam ratus empat puluh dua meter di titik terdalamnya. Ini juga danau tertua. Dua puluh lima juta tahun. Kebanyakan danau terisi sedimen seiring waktu. Baikal berada di lembah retakan yang masih tumbuh. Dasarnya turun lebih cepat daripada sedimen bisa mengisinya."

"Baikal," he said. "It is the deepest lake in the world. One thousand six hundred and forty-two metres at its deepest point. It is also the oldest lake. Twenty-five million years old. Most lakes fill in with sediment over time. Baikal is in a rift valley that is still growing. The bottom drops faster than the sediment can fill it."

Air di luar begitu jernih sehingga Polly bisa melihat batu-batu besar di dasar danau di area dangkal. Kejernihannya bisa mencapai empat puluh meter dalam kondisi yang tepat.

The water outside was so clear that Polly could see boulders on the lake floor in the shallow areas. The clarity is up to forty metres in the right conditions.

"Danau ini juga menyimpan," kata Igor, "dua puluh tiga persen dari semua air tawar yang tidak membeku di Bumi. Lebih banyak dari semua Danau Besar di Amerika Utara digabungkan."

"It also holds," Igor said, "twenty-three percent of all the unfrozen fresh water on Earth. More than all the North American Great Lakes combined."

Polly memandang danau itu. Tidak terlihat seperti dua puluh tiga persen dari apapun. Terlihat seperti satu benda biru yang tenang.

Polly looked at the lake. It did not look like twenty-three percent of anything. It looked like a single still blue thing.

Kereta berhenti di stasiun Slyudyanka. Igor turun. Dia menjabat ujung sayap Polly dengan dua jari, dengan serius. "Tiga hari memancing. Lalu pulang." Dia melambaikan tangan melalui jendela dan pergi.

The train stopped at Slyudyanka station. Igor got off. He shook Polly's wing tip with two fingers, gravely. "Three days fishing. Then home." He waved through the window and was gone.

Selama tiga jam lagi, kereta melaju di sepanjang pantai. Sekelompok anjing laut Baikal muncul di permukaan satu kilometer dari pantai. Mereka adalah satu-satunya spesies anjing laut air tawar murni di dunia.

For three more hours, the train ran the shore. A group of Baikal seals popped their heads above the surface a kilometre offshore. They are the world's only purely freshwater seal species.

Polly memikirkan tentang skala. Di bawahnya ada air yang lebih tua dari spesiesnya. Di dalam air itu ada udang kecil berwarna merah muda yang disebut Epischura yang tidak ada di tempat lain di Bumi. Udang ini menjaga danau tetap jernih. Sudah menjaganya tetap jernih selama dua puluh juta tahun.

Polly thought about scale. Below her was water older than her species. Inside that water was a tiny pink shrimp called Epischura that did not exist anywhere else on Earth. It kept the lake clear. It had been keeping it clear for twenty million years.