Poster Presentation 12th Australian Streams Management Conference 2026

Monitoring soil hydrology for giant Gippsland earthworm (Megascolides australis) on a streamside bank in Gippsland, Victoria (#8)

Michael Aberton 1 , Stephanie Phillips 2 , Elsa Burnell 3 , Bertrand Salmi 4
  1. Waterways and Ecology, Water Technology, Ballina, NSW, Australia
  2. Waterways and Ecology, Water Technology, Wangaratta, VIC, Australia
  3. Waterways and Ecology, Water Technology, Melbourne, VIC, Australia
  4. Living Lands and Water, Water Technology, Auckland, New Zealand

The Giant Gippsland Earthworm (GGE) Megascolides australis “GGE” has been identified by the Federal Government as a Saving Native Species (Priority Species). It is threatened and at risk through changes arising from altered soil hydrology from a variety of sources.  

In a pilot study over 21 months; we monitored soil hydrology in habitat of a healthy colony (determined by counts of audible “gurgles”) and in adjacent uncolonized land at Arawata, Gippsland. Soil moisture probes monitored soil moisture and soil temperature to 80cm depth and soil oxygen at 30cm.   

  • Gippsland had below average rainfalls for many months during the project duration.
  • Soil moisture closer the surface showed high variability with sharp increases after rain and rapid decreases during dry periods. As the soil depth increases the variability of soil moisture and temperature was more stable than weather dependant surface soils.
  • With the decline in soil moisture there was also a reduced number of “gurgles” heard.
  • Revegetation (small Eucalypt saplings) appeared to have a rapid decrease of soil moisture at depth in summer as a result of drawdown.

The decline in gurgles is a result of the conditions becoming less favourable for movement as habitat dries out. The project supports planting in zones to ensure soil water uptake by small trees and shrubs doesn’t occur near colonies. These results are important as they provide an insight into GGE that if soils dry out for whatever reason, the mobility of GGE declines and the species is at risk.