Greater than half of Tamar River wetlands misplaced since European settlement, examine reveals

Greater than half of Tasmania’s largest wetland system in kanamaluka / the Tamar River has vanished since European settlement, new analysis from the College of Tasmania has revealed.

The examine, printed in Estuaries and Coasts and offered on the Tamar Discussion board on 23 October, reveals that 1,157 hectares of wetlands within the Tamar estuary have been misplaced since colonization—a 52% decline from 2,231 hectares to simply 1,074 at present. The sample mirrors a nationwide story, with a few of Australia’s city estuaries shedding greater than 70% of their wetlands over the identical interval.

The Tamar wetlands as soon as fashioned a pure buffer between land and sea. Throughout Tasmania’s 2016 floods, which prompted virtually $180 million in harm, lots of the hardest-hit areas have been as soon as wetlands that had absorbed floodwaters and filtered sediment earlier than improvement claimed them.

The examine, commissioned by the Tamar Estuary and Esk Rivers (TEER) Program, was undertaken by a staff of researchers from the Faculty of Geography, Planning, and Spatial Sciences, led by Joshua Briggs and wetland ecologist Dr. Vishnu Prahalad.

To chart how the estuary has modified, researchers turned to sketches, early survey maps, and environmental information, evaluating them with Tasmania’s first aerial pictures from the Nineteen Forties. The result’s what Dr. Prahalad describes as a “time machine” of the panorama earlier than European interference.

“The size of loss is staggering,” he mentioned.

As soon as residence to Tasmania’s largest tidal wetlands, the Tamar estuary supported huge populations of fish, waterbirds and migratory species touring from as far-off as Siberia and Alaska. The examine offers the primary detailed report of how this ecosystem has modified since colonization.

Working with nature

The analysis additionally highlights options. In California’s Napa Valley, authorities opted to revive wetlands relatively than construct flood obstacles, gaining each pure flood safety and thriving tourism and recreation areas.

“This analysis offers a scientific basis to establish the place restoration might be focused and the place safety might be strengthened to help river well being,” Dr. Prahalad mentioned.

A trial wetland restoration undertaking is now underway on the North Esk River. If profitable, it may function a mannequin for related work throughout the Tamar and different catchments.

“Launceston has a novel alternative to steer in wetland restoration and grow to be the wetland capital of Australia,” Dr. Prahalad mentioned. “We now have a transparent image of the place the wetlands was. The query is whether or not there’s sufficient neighborhood and political help to carry them again.”