Not only is it subject to a range of pressures from mining, agriculture, industry and urbanisation; but it is also home to internationally important shorebirds and wetlands.

To promote the international importance of the Hunter Estuary Ramsar wetlands, in 1994 Newcastle and Port Stephens councils signed a Sister Wetland Agreement, called the Kushiro Agreement, with six Japanese councils.

Last week, a mayoral delegation from northern Japan visited Newcastle and Port Stephens to renew the 21-year-old agreement that gives high priority to wetlands conservation.

Kushiro mayor Hiroya Ebina, who is president of the Kushiro International Wetlands Centre in Hokkaido, led the four-person delegation.

Preservation of wetlands is vital to the continuation of an extraordinary natural phenomenon - annual bird migrations between wetlands of Hokkaido and the Hunter estuary, a non-stop journey of 8500 kilometres.

The wetlands include areas designated under the Ramsar Convention as Wetlands of International Importance.

The municipalities share a shorebird species called the Latham's Snipe (Gallinago hardwickii), which breeds in the Kushiro wetlands and migrates to the Hunter Estuary over the Australian summer to avoid the harsh Japanese winter.

About 30,000 travel between Japan and Australia each year.

This demonstrates the importance of continuing this partnership, through which we have been able to increase local awareness of the international significance of the Hunter estuary; and encourage community involvement.

The Sister Wetlands Relationship was first signed in Newcastle in 1994 and renewed for the first time in Newcastle in 2004.