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Granite rocks are unique wetlands

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Aboriginal NRM

In 2008 the wetlands of the Wheatbelt were mapped by DBCA and Wheatbelt NRM.

6400 granite outcrops were mapped as wetlands. The granite outcrops that are such a dominating landscape feature are considered as wetlands due to the freshwater pools they support.

The wetlands of the Wheatbelt are home to over 1000 species of aquatic invertebrates and many are found nowhere else in the world. In fact, the species variety found in one water pool on a granite rock will be completely different to the species found in another pool on the same rock.

The invertebrate fauna of these pools are unique as they have adapted to the unpredictable and temporary inundation periods with short life cycles.

These granite rocks and pools are also important to Aboriginal culture. The rock pools are known as Gnamma Holes. Noongar Elder Kevan Davis told us in the Derdebin Gnamma Book that “Gnammas were life-giving sources of water for my Noongar ancestors for many thousands of years.”

Gnammas are sacred. They were guarded and regularly cleaned. Slabs of rocks were placed over some smaller pit gnammas to reduce evaporation and prevent wildlife from falling in and drowning.

Some Noongar stories say gnammas were created in the dreamtime by the Wargal, the spirit snake that also made the rivers, lakes and wetlands. Another dreamtime story says that the row of five pit gnammas in Trayning were dug by a nyingarn (echidna) digging pits as he migrated south.

These rocky pools were integral to the survival and culture of the Aboriginal community. Special habitats like ancient granite outcrops are just one of the reasons the Wheatbelt has such a rich variety of unique plants and animals.

Take an aerial tour of some of the most impressive and important granite rocks and gnamma holes in the Wheatbelt by following this link.