SHANGHAI, Aug. 6 -- A GOVERNMENT clean-up project for an area of the East China Sea has been hailed as a success with a marked improvement in water quality and nearly twice as many species of marine life now being found there.

The 1.5-square-kilometer zone is within the Hangzhou Bay of East China Sea, near the beach of the Jinshan District.

"We have improved the marine ecology in the sea area and will maintain the standard," Chen Yaqu, a researcher of the East China Sea Marine Institute which is in charge of the project, said yesterday.

He said the water quality of the sea in the zone has been upgraded to level two, up from level four last year.

The city's water quality regulations set level one as the premium with level five the minimum standard.

As well 159 marine species have been identified in the zone - last year at the same time only 77 marine species were found.

Among the newly found species were fish from other areas including a type of perch never found close to the city before.

He said during the past year, the institute researchers, together with the Jinshan District government, conducted extensive studies on the water quality in the zone near the Jinshan beach.

The researchers introduced different marine plants - such as reeds and seaweeds - and other fish species to encourage the restoration of the ecological balance.

The project is part of the district's moves to improve the beach. Jinshan officials have not said how much has been spent on the project.

Despite the success with the sea, the city still faces severe environmental challenges in its rural rivers.

Several rural rivers have been reported as being "severely polluted" because of industry and agriculture.

In June, two tributaries of the Huangpu River in Pudong were reported to have "fish-killing pollution."