SAKAI, Osaka Pref. — After raising insects and fish as a boy, Akio Ueda moved on to a much bigger and more temperamental living organism: coral.
“I’ve mastered the knowhow of growing coral reefs” through trial and error over the course of five years, said Ueda, 41, who keeps different kinds of coral reefs in three large water tanks at his home.
Scientists and experts are struggling to save the world’s coral reefs, which are highly sensitive to the environment and are being damaged by global warming and pollution. They are notoriously difficult to grow artificially.
Ueda, a real estate firm employee, began keeping coral about a decade ago, although he was initially unable to keep it alive for more than a month. The advice of shop owners was of little help.
Ueda’s situation changed for the better around seven years ago, when he discovered “Reef Aquarium,” a technical book on coral written by American marine expert Delbeek Sprung.
“I was so astonished by the huge gap between what it says in the book and what was practiced in Japan,” Ueda said.
The book outlines a method known as the Berlin System, which teaches home growers to keep the water as close as possible to the coral’s natural environment.
To do that, home growers must regularly change the water, position the water tanks under bright lights that simulate sunlight and add chemical elements such as calcium to the water to help the coral grow. Keeping the water close to the coral’s natural environment enhances its natural activities.
Despite his enthusiasm, Ueda almost gave up his hobby a few years ago.
While he was away on summer vacation, his mother entered his room and switched off the air conditioning. In the stifling summer heat, the temperature of the water in the tanks rose as high as 40 degrees, nearly killing his coral reefs.
Although coral is found in tropical climates, it is important to keep it in water below 25 degrees, according to Ueda.
While Japanese experts at aquariums and other institutions have largely ignored the Berlin System, it has quickly spread over the Internet and been adopted by amateur coral growers.
Some aquariums have also come around, albeit slowly.
Osaka Aquarium Kaiyukan, for example, has adopted the Berlin System.
A Kaiyukan official said the employees there sometimes gain valuable knowledge from experienced and enthusiastic amateurs.
But Ueda is now looking for bigger challenges.
“Once you have acquired the method, it is not difficult to keep them,” he said. “I would like to try more difficult kinds.”