MUROTO, Kochi Pref. -- At first glance, it is hard to see what the following products have in common: bottled water, miso paste, bread, snacks and skin lotion.

The answer is that they are part of a legion of nearly 40 products that contain seawater taken from a depth of 374 meters in the ocean off the Muroto Peninsula, on the southeastern tip of Kochi Prefecture.

Products containing deep seawater have become something of a hit in the last few years, as the liquid is touted for its purity and high mineral content.

It remains to be seen, however, whether this new business will evolve into a major income generator to help revitalize Muroto's economy, as other local governments and private firms are intensifying market competition amid rapidly changing consumer tastes. he city of Muroto is determined to prevent the use of deep seawater from becoming just another passing health fad. It is promoting scientific study of the seawater and its effects in the hope of discovering properties that will make it a more lasting commodity.

"Although studies so far have found that deep seawater is rich in minerals and very pure, we don't know, for example, the mechanism behind its acceleration of the fermentation process," said Masao Niiya, deputy mayor of Muroto and a key figure in the seawater project. "I think it is important to conduct basic scientific studies to nurture the business into a major industry."

Although Niiya was involved in the creation of a framework to promote businesses that use deep seawater while he was at the Kochi Prefectural Government between 1995 and 1998, he said he is surprised by the recent deep seawater product boom.

The prefectural government had been conducting deep seawater studies at its research institute in Muroto since 1989, after it was designated by the central government as a model site for such research. Because no major findings were made, the prefectural government decided to allow private companies to use the water and provided them with access to one of its two water-intake pipes in 1995.

Major cosmetics firm Shu Uemura Cosmetics Inc. then triggered the current deep seawater boom when it launched a skin lotion containing the water in August 1998.

Following this, various products using deep seawater have been marketed and have sold well. According to the city, around 100 companies now produce deep seawater-related products using water from Muroto.

Last year, sales of such products totaled 3.9 billion yen, up from 180 million yen in 1996, according to the prefectural government. More than 100 jobs have been created in the prefecture in the wake of this success.

Initially, the prefectural government had been providing companies with deep seawater after studying their applications for the water's use. Effective control of the Muroto water shifted to the city, however, after the opening of the municipal government-run Muroto Aqua Farm on Cape Muroto in April to sell deep seawater to businesses and individuals.

The farm sells natural deep seawater at 400 yen per ton for city residents and 500 yen for those living outside the city. Desalinated water is sold for 5,100 yen per ton to those living in the city and 6,500 yen for nonresidents.

According to Aqua Farm, some 13 million liters of deep seawater was sold in November alone. Aqua Farm also has a facility in which products are displayed and deep seawater is explained.

Prospects for the deep seawater business are not, however, as bright as local officials would like to believe. Other prefectural and municipal governments -- as well as private companies -- have begun jumping on the bandwagon.

A third-sector company set up by the Namerikawa Municipal Government and some private businesses in Toyama Prefecture not only sells bottled mineral water but also runs a facility for so-called thalassic therapy. The Shizuoka Prefectural Government meanwhile plans to pump up deep seawater in the city of Yaizu in April, while some cities and towns in Hokkaido and Okinawa also have similar projects.

Whether consumers remain interested in deep seawater products is another issue. Hyogo Prefecture-based Ako Kasei Co., which sells cosmetics and salt, was the first company to begin selling bottled mineral water using deep seawater from Muroto in June 1999.

Although its sales marked a steep increase in the last year following a TV program that featured its health properties, a company spokesman admitted that the boom appears to be receding.

The large influx of various deep seawater products onto the market has also highlighted the need to differentiate between products containing Muroto deep seawater and those that do not, and also to certify that a product really contains Muroto seawater as its manufacturer claims.

As a first step toward solving these issues, in October the Muroto government succeeded in inviting biotechnology experts to Kochi University of Technology's newly opened life and environmental engineering section.

As a means to help finance the research, which is currently being funded by businesses, the municipal government will introduce a system next October in which firms that manufacture products using Muroto deep seawater pay royalty fees.

In return, the firms will be allowed to use a logo that will certify that the water is from Muroto. As part of this certification system, the city will also draw up criteria in order to define what exactly can be called Muroto deep seawater.

"We have received favorable responses to the idea from businesses, even though we have yet to decide how much we will charge (for the use of the Muroto logo.) This is probably because companies for their part also want more detailed scientific data to keep their business going," Niiya said.

"If more (about the water's properties) is known, it may lead to new businesses in such fields as medicine. . . . My hope is to make the deep seawater business grow as a national project."