“Damage to wetlands there could threaten migratory bird populations in the East Asian-Australasian Flyway,” Wong Suet-mei, a conservation officer at the Hong Kong Bird Watching Society, said.

The flyway is one of the major migratory routes for birds in a span from New Zealand to Alaska. It supports 50 million migratory birds a year, including 32 threatened and 19 near-threatened species.

Other activist groups involved in the campaign to protect the site include the Conservancy Association, Green Power, Greenpeace and World Wide Fund for Nature.

The proposal to earmark 627 hectares of land in the city’s northwest to establish an innovation and technology hub and provide more than 50,000 homes was put forward by the Development Bureau last month.

About two-fifths of the San Tin Technopole, 248 hectares, is regarded as biologically sensitive, with areas such as wetlands, fish ponds and water catchment zones.

‘Land granted under Hong Kong technopole cannot be left vacant, sold arbitrarily’

Then chief executive Carrie Lam Cheng Yuet-ngor said in 2021 that the Northern Metropolis would include three wetland conservation parks covering a total of 1,220 hectares, including a 570-hectare site in Sam Po Shue, in Yuen Long.

Wong added that the wetlands in the proposed technopole had a “close ecological connection” with the Mai Po Inner Deep Bay Ramsar Site, a nearby nature reserve designated in 1995 for migratory bird and mangrove conservation.

The Agriculture, Fisheries and Conservation Department last August launched a feasibility study on establishing a wetland conservation park system in the Northern Metropolis. The department’s report is expected to be published in December.

The Development Bureau in the meantime announced the San Tin Technopole proposal in May and started a three-month public consultation programme.

The Development Bureau earlier said the San Tin Technopole would affect only 90 hectares of wetlands and fish ponds.

Don’t build I&T hub on Hong Kong wetlands without conservation park plan: experts

But Wong said research done by the green groups identified 205 bird species in the proposed development area, which was also home to 19 critically endangered and endangered species.

She added that the black-faced spoonbills found in the area were 30 per cent of the city’s population and 1 per cent of the global total.

The United Nations Convention on Biological Diversity ruled a wetland should be considered of international importance if it regularly supported 1 per cent of a population of a single species or subspecies of waterbird.

Kristy Chow Oi-chuen, a campaign officer for the Conservancy Association, said about 141 hectares of the Sam Po Shue wetland conservation park overlapped the proposed San Tin Technopole site, which raised concerns about the integrity of the protected area.

“The Development Bureau proposed the San Tin Technopole plan before the Agriculture, Fisheries and Conservation Department released the complete ecological science survey results,” she said. “It is in contrast to the planning intention of a wetland conservation park.”

In response to a Post inquiry, the Development Bureau said it would avoid affecting the migratory birds’ habitats and flight corridors for the proposed technopole, and that the acquired fish ponds would be used in a “rational” manner.

“Of the 248 hectares, 159 hectares are brownfields, filled fish ponds and other lands of low ecological value,” a spokeswoman said. “About 90 hectares of the remaining fish ponds are proposed to be filled, half of which have not been used for aquaculture or have been abandoned for many years.”