Tokyo

A Japanese research team is putting the finishing touches to a satellite-based whale-tracking system that looks set to fuel the international debate on whale conservation.

The system — the brainchild of Tomonao Hayashi, an engineer at the Chiba Institute of Technology — will use a satellite to probe the whereabouts of hundreds of whales.

Hayashi hopes the project will help to resolve the ongoing debate about Japan's whaling programme. Japanese researchers, mainly at the Institute for Cetacean Research (ICR) in Tokyo, say that whale stocks are sufficient to warrant hunting; the International Whaling Commission disagrees. To prove its point, Japan has been carrying out controversial 'research whaling', killing about 400 whales per year. “Both sides know too little about the whale's ecology to reach a conclusion,” says Hayashi.

The project will initially involve just one or two whales until it proves its merit internationally, Hayashi says. The education ministry has invested ¥300 million (US$2.3 million) in the plan, and the satellite will be launched as part of Japan's Advanced Earth Observing Satellite II (ADEOS-II) project.

Researchers will tag the whales by using an airgun to shoot a titanium pin into the blubber, a procedure that Hayashi describes as “minimally invasive”. A probe, attached to the pin by a two-metre rope, will send signals to the satellite.

Apart from allowing monitoring of migratory patterns and whale acoustics, the probes will record pressure and temperature, and take geomagnetic readings during whale dives, which can last for 10–30 minutes. Data will be relayed to the satellite whenever the whale surfaces. “Sperm whales are thought to dive 2,000–3,000 metres during this time, but no one could tell for sure,” says Hayashi.

Hayashi is developing a special generator to recharge the probe's batteries — a propeller-like machine that will derive energy from the whale's motion through the water. Although the whales will probably be stuck with the pin for life, Hayashi plans to attach the rope and probe with an iron fastener that will eventually rust away.

Seiji Ohsumi, director-general of the ICR, says the research will be “epoch-making”, adding that the project will help the institute to work on rational stock management.