Stygofauna

What are they?

Stygofauna are subterranean aquatic animals that live only in groundwater, perfectly adapted to life in permanent darkness. Mostly invertebrates and rarely more than 5 mm, they include water mites, molluscs, insects, fish and more.

Stygofauna can be found in rock types such as karst (limestone), fissured rock like granite and porous rock like alluvium. They’ve been recorded in several areas of Western Australia including;

The calcrete and alluvial aquifers in the Pilbara and Yilgarn plateau;
Cape Range Peninsula;
Carnavorn Basin;
Swan Coastal Plain;
Leeuwin-Naturalist Ridge;
The Nullabor Plain; and
The sandstone and limestone of the Kimberley.

Conservation issues

The biology, life cycles, reproduction, feeding, survival strategies, longevity and endemicity of stygofauna species are little known although their importance for the quality of ground water is now being recognised.

Stygofauna depend completely on the conservation and maintenance of the groundwater aquifer system including the areas above the aquifer where food resources are derived and carried into the cavities (groundwater zones) by rainfall.

As such, stygofauna are extremely vulnerable to artificial disturbances such as;

Clearing (which increases the sediment in groundwater);
Modification to groundwater recharge areas;
Groundwater pollution;
Groundwater abstraction;
Salinisation (post mining); and
Direct excavation.

These activities may influence the connectivity or flow rate of aquifers and affect the capacity for exchange of organisms between areas and/or populations, which leads to an overall decrease in diversity and disrupts stable ecosystems. As such identifying the composition of stygofauna communities has become an essential part of Environmental Impact Assessments and project approvals.

Capabilities

At Ecologia Environment, our team of industry-leading invertebrate zoologists specialise in the survey, identification and management of Stygofauna. Our team of specialists are well regarded in this field; maintaining good rapport with regulators and members of academia.

Read about Ecologia's Stygofauna Environmental Management