Protecting the Giant Gippsland Earthworm
Understanding colony locations and habitat requirements
Endemic to south-west Gippsland in a triangle roughly bounded by Loch, Korumburra and Warragul, the Giant Gippsland Earthworm is one of the largest earthworms in the world, growing up to 100 cm long, 2cm wide and weighing up to 200g. Through this initial project, earthworm colonies on 10 properties were studied with the intention of providing landholders with guidance on planting to protect habitat.
Project 1 description
In 2021 GTSAG, in partnership with Bass Coast Landcare Network, South Gippsland Landcare Network and Trust for Nature, received a grant from the Federal Government awarded under the Environment Restoration Fund-Threatened Species Strategy Action Plan-Priority Species Grants.
The project is entitled ‘Enhanced Knowledge and Protection of the Giant Gippsland Earthworm.’
This enabled the identification of Giant Gippsland Earthworm (GGE) habitat on farms and provided recommendations on habitat management. The project builds on the GGE National Recovery Plan (2010) recommendations by permanently protecting GGE colonies and habitat with two Trust for Nature Covenants and nine non-perpetual landholder agreements.
The project also conducted botanical assessments of GGE habitat and established long-term monitoring sites to produce refined Ecological Vegetation Class (EVC) species lists more suitable for GGE habitat.
Project 2 description
In 2024, GTSAG was awarded a further grant for the Giant Gippsland Earthworm (GGE) project from the Federal Government’s Saving Native Species (Priority Species) Program.
The project will increase the knowledge of colony locations, habitat requirements, communicating knowledge to landholders on appropriate land management that will protect colonies, and increase our knowledge of soil hydrology requirements for GGE.
Alteration of the water table and natural drainage patterns, exacerbated by climate change, is one of the most serious threats to GGE populations yet is currently poorly understood. Surprisingly little is known about soil and hydrological parameters for suitable habitat and the threshold for GGE tolerance to hydrological change. This project could reveal vital information on soil hydrology and GGE survival in the long-term.
This project will work with Water Technology hydrogeologists to undertake a pilot study to accurately measure soil moisture, temperature and oxygen levels in thriving GGE colonies in comparison to adjacent habitats not supporting GGE. Hydrological changes in the water table and ground water profile will be monitored over the life of this project and beyond.
Image: Installation of soil probes, Arawata. Photo by Dr Michael Aberton, Water Technology.
Project 3 - ‘A census of Giant Gippsland Earthworm distribution in South and West Gippsland’
This project aims to address gaps in distribution status and trends for the Giant Gippsland Earthworm (Megascolides australis).
The Giant Gippsland Earthworm is listed as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and has been recognised as a priority species under the Threatened Species Action Plan 2022-2032.
Giant Gippsland Earthworms are found in south and west Gippsland in Victoria, mostly on private land with limited connectivity between populations. They rely on high soil moisture almost year-round to keep their burrows suitably wet and are facing threats from climate change and other activities that reduce soil moisture or cause chemical disturbances to soil. This GGE Census is also funded under the Federal Government’s Saving Native Species (Priority Species) Program.
Project objectives
This project will provide much-needed information on species distribution and population size. It will update and expand on a previous population census to fill knowledge gaps that limit conservation planning and management and help support efforts to improve the trajectory of the species. The objectives of the project are to:
- Digitise and consolidate historical and contemporary records and conduct analysis to identify the expected population distribution.
- Work with and survey landholders to locate populations, and conduct on-site verification, where appropriate, to determine baseline data on current population distribution and size.
- Analyse and map distribution data and conduct analysis to improve our understanding and identify any change in distributions or population size from historical data.
- Develop an online open-use application for users to capture location data on future Giant Gippsland Earthworm sightings.
*The Enhanced Knowledge and Protection of the Giant Gippsland Earthworm project is supported through funding from the Australian Government.
