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Drifting Buoys Designed for the Iridium System

Traveling three thousand sea miles to meet their mothers!?—Where do you think Japanese eels hatch from eggs and grow into glass eels before coming back to coastal waters around Japan?
As a matter of fact, Japanese eels spawn in waters to the west of the Mariana Islands, which are located close to Guam Island, as shown in the map below. Larvae hatch from eggs in these waters and grow into glass eels as they are carried by the Kuroshio Current all the way from waters to the east of the Philippines. These glass eels, which have remarkable swimming ability, leave the Kuroshio Current, their cradle, as they approach the shores of Japan, in order to start new lives in rivers and brackish waters (zones where fresh water and sea water mix with each other).
Thus, glass eels are not born in coastal waters around Japan, but after being hatched from eggs travel a total of three thousand sea miles for four to five months before they reach the coast of Japan—i.e., they travel three thousand sea miles to meet their mothers!

We learned this interesting story from Professor Kimura at the Ocean Research Institute, the University of Tokyo, who is the authority on Japanese eels, when we received an order for drifting buoys designed for the Iridium System from Professor Kimura, who had high expectations about our newly released buoy model. Even more interesting than the above story is the question: How do parent eels travel to the spawning grounds in the first place? And here is Professor Kimura’s answer to that question: “That’s why we need so many of these drifting buoys (laughs).”

Between July 8 and July 10, three drifting buoys designed for the Iridium System, which had just been released in June, were launched in the spawning grounds of Japanese eels. These buoys are expected to be carried by the Kuroshio Current, along with glass eels, to coastal waters around Japan sometime in or after this fall.

Data sent from buoys drifting in waters thousands of miles away reach Japan in about a minute. We will apply the latest satellite communication technology to ocean monitoring sooner than any other company and will further develop our expertise in order to receive a high evaluation for our drifting buoys as a sturdy device that supports ocean monit monitoring.

視認風景