Port Waratah is very proud to be a partner in the development of seven new artificial ‘cluster’ ponds established within the Hunter Wetlands National Park on Ash Island near Kooragang which will enable endangered green and golden bell frogs located on the north and south of Ash Island to mix more easily.

The series of ponds will help connect two groups of endangered green and golden bell frogs located on the north and south of Ash Island and provide breeding habitats and refuges in dry periods to help rebuild frog numbers.

The project is in partnership with NSW Parks and Wildlife Service, Trees in Newcastle, Hunter Local Land Services, The University of Newcastle (UoN) and Newcastle Coal Infrastructure Group (NCIG).

Monitoring by UoN and the NSW Government’s Saving our Species Program in 2023-24 found low numbers of green and golden bell frogs on Ash Island, including in the Hunter Wetlands National Park, probably due to lower than predicted rainfall during the breeding season. The information helped the team understand that artificial sources of freshwater regularly spaced across the island could likely help the frogs survive dry years, plus allow them to move more easily across the island.

UoN also realised there was very little movement between the smaller northern bell frog subpopulation and the larger southern subpopulation, so the recommended placing of artificial ‘cluster ponds’ across the island would help the frogs mingle while providing drought-resistant breeding habitat.

The ponds were designed with input from the UoN, the Saving our Species Program and local industry partners, including Port Waratah, that monitor green and golden bell frogs across the Kooragang wetlands.

The design builds on trial ponds first constructed by Port Waratah in 1997 and supplements the artificial pond features incorporated by Hunter and Central Coast Development Corporation as part of remediating and managing the former Kooragang Island Waste Emplacement Facility.

Each new ‘cluster pond’ has one large, 1.5 metres deep circular tank-pond to provide permanent fresh water and a shallow three-chamber trough to provide preferred breeding habitat. Frogs can enter the lower ponds or hop up rock-basket ramps to access the large tank for a deeper dive.

The wired-together rock ramps also provide hidey holes in cracks and crevices, in which the frogs can heat-up in a “frog sauna” from the sun-warmed rocks. Heat can help the frogs shed the deadly chytrid fungus, which is one of their biggest threats. The ponds are also raised above ground-level, preventing tiny, introduced tadpole and egg-eating fish called Gambusia from washing into them after heavy rain.

In November, a dozen Port Waratah employees together with volunteers from the project partners planted native plants and vegetation around the cluster ponds helping to connect the frog populations previously isolated in the north and south of Ash Island. The frogs use the foliage to safely move across distances and easily access the newly installed ponds.

There is potential to build up to 20 more ponds at strategic locations across Ash Island over the next four years. The project is supported by funding from Port Waratah, NCIG and the NSW Government.