Jacinda Ardern welcomes godwit protection plan

Godwits are one of our most treasured shorebirds, but they're in decline.

Now, an international deal involving China could help by making their annual migration safer. 

Godwits are among the world's most remarkable travellers, making an epic journey each year from the Southern Hemisphere to Alaska and back again.

They make a vital stop along the way in the Yellow Sea, between China and Korea.

"They arrive there having used all their resources and they need to refuel again and that's why the Yellow Sea's so important," says Pukorokoro Miranda Shorebird Centre manager, Keith Woodley.

"And then from there to its various breeding grounds it's only a few thousand kilometres, so they can arrive on the breeding grounds in good shape."

But a lot of the mudflats they rely on to feed in the Yellow Sea are gone - which is what's believed to be causing a decline in numbers of shorebirds.

Godwit populations have been declining by 2 percent a year for the past 10 years, and the red knot species even faster.

On Monday, Prime Minister Jacinda Ardern and Conservation Minister Eugenie Sage welcomed news that parts of China's Yellow Sea will become a World Heritage site.

"It's the recognition of the importance of retaining mudflats so that they're not reclaimed for development," Sage says.

"There's been the loss of about two-thirds of the mudflats in that area but now China is committing to their protection."

An agreement signed in May will see the Department of Conservation work with China's National Forestry and Grassland Administration to protect these important stopover sites for migratory birds.

"It means that we may be able to stabilise some of these populations," Woodley says.

"We may be able to hold the line so there's no further habitat loss and if we can do that, these birds might have a future."

And New Zealand's doing its part too, with work being done to protect habitats on this side of the Pacific, helping to secure their long-term survival.