The tidelands of Isahaya Bay, Nagasaki Prefecture, were home to the largest number of migrant birds in Japan in 1996 -- a year before a controversial reclamation project cut it off from the bay's life-giving waters with a gate, the Environment Agency said Sept. 8.

For the first time since it started research in 1988, the agency has compiled a list of domestic wetlands that accommodate birds during their seasonal migrations in an attempt to designate key sites in need of protection.

According to a report released by the agency Sept. 8, 73 wetlands throughout 13 areas have been listed as vital accommodations for migrant birds. In each of those wetlands, over 5,000 migrant birds were found after a single counting. Wetlands that are home to endangered species of migrant birds are also on the list, agency officials said.

Among the 73 locations, the tideland in Isahaya accommodated a record 9,424 birds in May 1996, followed by the wetlands downstream of the Shonai River, Aichi Prefecture, that hosted 6,950 birds the same month. More than 11 species, such as the Gray Plover and the Kentish Plover, were confirmed at the Isahaya tidelands, while at least 14 species, including Gray-Headed Lapwing and Bar-Tailed Godwit, were spotted on the Shonai, the report said.

In Isahaya, the number of birds has decreased considerably since April, when the tideland was completely separated from the sea by a water gate built into an embankment cutting across the bay.

Meanwhile, the Tazu tideland in Tokyo Bay, which enjoys the protection of the Ramsar Treaty of 1971, ranked fifth, with 5,120 birds confirmed in April 1989. The list includes some locations where development projects are planned or have already been launched, such as the Wajiro and Sone tidelands in Fukuoka Prefecture.

Although the report is not binding and has little authority to stop ongoing development projects, the officials said the agency and 18 concerned prefectures will hold a conference in October on wetland protection. In Japan, 10 areas are protected under the Ramsar Treaty. More than 100 countries have signed the treaty and a total of 62.53 million hectares of wetlands in the world are under international protection.