Rangelands NRM Blog, News & Resources

Knowledge of threatened cave dwellers increased

[January 2015]

Scientists have been undertaking work to increase their knowledge of threatened species living in underground caves in the north-west rangelands of WA.

Funding from Rangelands NRM is assisting the WA Museum to further develop understanding of the aquatic and terrestrial subterranean species found in Camerons Cave, south of the Exmouth townsite on the Cape Range peninsula.

The survey is being led by WA Museum’s Senior Curator Collections and Research, Dr Bill Humphreys, with assistance from Darren Brooks of KarstBioSearch.

Rangelands NRM Program Manager (Southern Rangelands) Jane Bradley said Camerons Cave is a recognised threatened ecological community which contains a number of threatened species of troglobionts (cave-dwellers).

This survey work, undertaken as part of the œProtecting Karst Cave Communities project, is collecting water quality data both in Camerons Cave and adjacent parts of the Exmouth coastal plain to further verify the nature of the hydraulic connection between Camerons Cave and the ocean.

According to Dr Humphreys from the WA Museum, the present knowledge of the Camerons Cave troglobiont fauna is based on a short period of collecting by hand and sometimes artificial environmental supplementation (litter traps) during the early-mid 1990s, and has been entirely focussed on terrestrial troglofauna.

Troglobiont fauna of the Cape Range are related to the fauna of wet forest floor litter communities.

“To attract these critters to a place where they can be recorded, it is necessary to modify small areas of Camerons Cave and other caves on the coastal plain with cave access that are accessible to humans, to provide the humidity and access to organic carbon that troglobionts require,” Dr Humphreys said.

In addition to the water quality sampling, sampling of stygofauna (groundwater-dwellers) is also being undertaken.

Dr Humphreys said although the sampling period to date has been short, a number of stygobionts were recorded from areas where they had not previously been recorded.

“These amphipod (shrimp-like) crustacean specimens from Camerons Cave are the closest known to Neds Well, the original collection site of the genus Nedsia but a site which has not subsequently been accessible,” he said.

The Camerons Cave material will serve to anchor the molecular studies on this genus of amphipods which is represented by many species in the Pilbara and Barrow Island.

The project runs for another six months during which a further Autumn sampling will occur.

“The year-long data set will add to existing knowledge of Camerons Cave and its cave dwelling critters,” Ms Bradley said.

Images

(Left): The amphipod Nedsia sp. from CC01; N. douglasi was originally described from the now defunct Neds Well on the Harold E. Holt military base north of Exmouth.

(Right): Fitting litter traps into CC02, one of the monitoring bores for Camerons Cave.

(Images: Humphreys 2010).