Giant Gippsland Earthworm
World's largest worm is endangered
The Giant Gippsland Earthworm, the world's largest worm, belongs to a family grouping known as Megascolecidae. It is found only in The Bass Valley and parts of the catchment of the Powlett River in Gippsland and can grow up to 3.7 metres long.
It typically has a length of 2 to 3 meters (up to 10 feet) and is about 2 centimetres (around ¾ inch) thick. The longest worm ever recorded was 4 metres (13 feet) long.
The skin is a pinkish-gray color and the head is a deep purple. They live close to the surface in red, gray or blue clayey soil often under stream banks. They need water to survive so they never leave their moist underground maze. If you stamp the ground near them, they make a gurgling sound as they hurry away through their damp tunnels as fast as they can. (It's not them making the noise, it's the sound of their bodies against the tunnel wall).
The Giant Gippsland Earthworm mates during the spring and summer seasons and lays brown colored egg sacs that measure 5 to 8 centimeters, (2 to 3 inches), long. The eggs take up to 1 year to fully develop and hatch. The baby worms are born with already an impressive length of about 20 centimetres (8 inches).
Giant Gippsland Earthworms are now a protected species because of the decline in population. It is so fragile that being dug up or handled by humans can kill it. It also can't stand the disturbance that agriculture and soil compaction by herds of animals. The use of herbicides and pesticides is also a leading cause of its disappearance since most of these are toxic to the worm when absorbed into the earth. As the worm tunnels through the ground, it ingests and absorbs nutrients (along with any chemicals we have put there). They keep soil healthy by decomposing organic material, recycling plant nutrients and improving soil structure.
Its habitat is very specific, which is why it is endangered. On top of the pressures placed on it by loss of habitat, agricultural practices and development, it is now identified as being at risk because of climate change. It needs forested land with blue grey or red clay soils along stream banks, gullies, soaks and some south or west facing hills.
With most of the native vegetation having been cleared, there's little wonder the worm is having a tough time. If the scientists are right about climate change, the GGE is probably headed for extinction.
Bass River flows
There has not been much survey work done on the Bass River over the years and the latest Regional River Health Strategy rates the river as 'low regional significance' It certainly deserves a higher rating than that because the Bass Valley is the source of potable for the whole regional - including Phillip Island.
People on Phillip Island often don't realise that without the Bass Valley they wouldn't survive - but we would get along quite happily without them.
Melbourne Water is currently undertaking an investigation into the environmental flow requirement for the river because of an application by Westernport Water to pump from the Bass to augment its water supply in the Candowie Reservoir. That study is being conducted with community input and should be completed in April or May this year.
Handling kills the earthworms
When the Giant Gippsland Earthworm was first discovered in 1878, it created quite a sensation and countless numbers were dug up. What wasn't realised for many years was that their skin is very delicate and easily damaged by handling. Simply holding an earthworm - such as in this picture - ensures that it will die within a few weeks. Live displays of the worms were set up much to the disgust of many ecologists who realised that these commercial enterprises had to dig up a constant supply to maintain their 'attraction'. It was totally incongruous that although the Giant Gippsland Earthworm was listed as an endangered species, it was OK to keep digging them up to replace the ones that died in display tanks. Thankfully that doesn't happen any more (at least we are not aware of it happening now).
The earthworm below is a species of segmented worm found in the Strzelecki Ranges. Its distribution and habitat requirements are unknown - in fact almost nothing is known about it at this stage!
It is found in rainforest areas - which is one reason for the importance of the creation of a reserve based on the 'Cores and Links' identified by Biosis Research. If unfettered logging continues, the earthworm and the Strzelecki Koala population are likely to become extinct.
