A meizanologist's diary (136)

2 April: sailing south by boat, riding north on horseback (nansen-hokuba, 南船北馬) is a four-character expression that describes the urge to madly rush about. This being precisely the impulse that overtakes me when a Japanese Rail Pass is about to expire, I let the Hokuriku Main Line waft me down to Kusatsu.

Although it may seem off-script for a meizanologist to visit a museum dedicated to a lake, an exception has to be made here. As a geological phenomenon, Lake Biwa is remarkable not just for its size – the largest freshwater expanse in Japan – but for its age. Most lakes fill in quickly, yet Biwa-ko has endured for four million years, helping it to sustain sixty or so endemic plants and fish.

An exhibit in the endemic Lake Biwa Museum explains why. The reconstructed site of a geological fault line shows how the lake’s rocky floor has kept sinking over time, at roughly a metre every thousand years. 

I’m reminded of the folk tale that a Godzilla-like giant Daidarabotchi excavated Lake Biwa, all in a single night, and piled up Mt. Fuji from the left-over spoil-tip…

Back in the museum, a diorama takes us into the deep past, when elephants roamed through forests of metasequoia and crocodiles lurked at their watering holes. 

One of the elephants later caused a sensation. In 1804, when people found its fossilised bones on the lake’s western shore, they thought at first they’d found a dragon.

From geology, we move into historical times. In the feudal era, long maruko-bune plied the lake, moving as elegantly if not quite as fast as a modern N700. 

There’s also a typical lakeside house, set up as it was in 1964, when water came from a stream and the nightsoil went straight onto the vegetable patch. In his Japan Journals, Donald Richie recalls how this latter practice led in the late 1940s to what he wryly calls a reverse Occupation…

After an hour or so among the cultural exhibits, I decide to make shorter work of those on insect and plant life.

After nodding to a giant dragonfly, I follow the children who are tugging their parents in the direction of the museum’s famous aquarium. 

Somehow I manage to miss an encounter with a giant catfish, the so-called lords of Lake Biwa.

This may be because I’m distracted by a friendly seal, who seems to be inspecting his visitors as curiously as they are inspecting him. Surely he can’t be an endemic? But, no, the seal is a Russian émigré, imported from Baikal, presumably a Twin Lake. I hope he isn’t missing the depths and ice sheets of his native waters.

Patrons should note that there is only one bus an hour from the museum back to Kusatsu station. Before catching it, I stroll out onto the outdoor viewing platform. A brisk spring breeze is whipping up white-capped waves out on the lake.

Under the clear sky, I start to appreciate Lake Biwa's size. It seems entirely reasonable that scooping it out would leave you with a Mt. Fuji-sized spoil-tip. How sad that the volumes don’t match up. No, not at all – the savants have calculated that you’d need to dig out something like fifty Lake Biwa basins to pile up just one 3,766 metre-high mountain. Now even for a Daidarabotchi, that sounds too much like hard work...