According to a 2021 study in the Journal of Environmental Management by Micha Jackson and colleagues, smooth cordgrass was introduced to China in 1979 to turn tidal flats into dry land. Have you ever been on a long road trip, running on empty, only to find the rest stop you were counting on closed? Some birds that migrate along China’s coast face something like that.
The study says the grass reduces the feeding and resting space that shorebirds depend on.
It has spread rapidly since then.
The Jackson study says the grass reduces feeding and resting space, and may be most destructive where tidal flats have already been lost. The Jackson study notes that it grows mainly on bare tidal flats, and can gradually replace open mud with dense grass. Shorebirds rely on tidal flats for food . The Emu review makes a similar point, saying the spread has removed roosting sites and smothered feeding grounds.
Smooth cordgrass was introduced to Jiangsu Province in 1979, according to a 2016 review of the species in the journal Emu by David Melville, Ying Chen and Zhijun Ma. It said the plant had spread along more than 400 kilometers of coast. By the early 2000s, it had developed into bands up to 4 kilometers wide.
Not the only threat, and what comes next
The National Forestry and Grassland Administration said in February 2023 it aimed to bring the plant under effective control nationwide by 2025 and clear more than 90% in various provinces. The administration has since reported that its national clearing task of 1.46 million mu (about 97,000 hectares) was completed in 2025, and in 2026 it set a new goal of keeping the plant cleared nationwide through 2030. The 2021 study authors say there is an urgent need to stop further tidal flat declines and build a full control program for the plant.
China has also launched a special campaign to control the plant. Because of tidal flat loss from land reclamation and other processes, the Jackson study says several species have declined. The grass is not the only problem. The threats listed in the Emu review along China’s Yellow Sea coast include aquaculture, harvesting and pollution. So cordgrass is one part of a bigger puzzle.
Officials said they would strengthen monitoring, boost scientific and technological support and improve relevant laws .
