Shanghai Daily news

The city's largest wetland is limiting the number of visitors to protect its wildlife, especially migratory birds.
Chongming dongtan Wetland has been listed as an important nature reserve since 2002 in the Ramsar Convention on Wetlands, first raised in 1971 and then amended in 1982 under the direction of the United Nations Educational, Scientific and Cultural Organization.
The wetland is 241.55-square-kilometer and an important resting area for migratory birds moving from one hemisphere to another.
"The protection of Dongtan Wetland is the foundation of our county's development plan," said Wu Xiaofei, vice director from the communication office of the county government. "Without it, all of our eco-construction will be in vain."
The number of birds in the wetland fluctuates, affected mainly by tourism and fishing.
To avoid unnecessary disturbance, visitors are no longer been allowed to trudge through the wetland. Visitors are only allowed to take a look from a man-made viewing corridor outside the wetland.
Yan haiwei, director general from Chongming Dongtan Nature Reserve, said: "The wetland should be a scenic base for eco-education and not a tourist destination." According to Yan, the corridor has been built to satisfy people's curiosity. They will also provide research data for visitors that explains the function of the wetland's ecological system.
Since last year, anyone wanting to enter the wetland has had to apply for a permit stating the purpose of their visit. A permit is given only to ecological researchers.
Scientists applying for a permit need to provide a synopsis of their researching and a guarantee from their institution.
Moreover, photos need to be taken before ecologists start walking through the wetland.
The office declined to say how many researchers are given access to the area. It said the figure is based on changing conditions in the wetland.
Usually the number of birds peak between September and April. During that period, the wetland is only accessible to scientists with special assignments.
The county will also establish a 20-hectare research center at the end of next year that is devoted to the wetland's protection.
According to Yan, researchers will not only study Dongtan's migratory birds, but also the people living nearby.
Many inhabitants near the wetland operate fish farms. Yan said they are trying to prevent people from disturbing the birds, while preventing the birds from eating the farmers products.
He also predicts more natural resources in the wetland will be discovered and utilized for eco-friendly development.
Land available for farming and urbanization increased from about 600 square kilometers to more than 1,200 square kilometers in the past 55 years in Chong-ming. The increase was due to wetland areas being infringed upon for modernization.