Edgbaston Goby

Think central Queensland and Longreach, and perhaps the home of Qantas comes to mind. You may even recall it as the area where that most Australian of folk songs, Waltzing Matilda, was written.

Odds are you won't have heard of the critically endangered Edgbaston Goby, found in only a handful of artesian springs and one of Australia’s most endangered fish.

It lives in just a handful of artesian springs on our Edgbaston Reserve in central Queensland, in a spring on neighbouring Myross Station and further downstream in the Pelican Creek catchment, in a bore drain (artificial habitat) on Ravenswood Station.

Artesian springs

Artesian springs are often only a few centimetres deep. Tussocks and many endemic plant species grow in the small, shallow, clay-bottomed pools. The springs are fed by the Great Artesian Basin, a vast subterranean reservoir of water that stretches through Queensland, the Northern Territory, New South Wales and South Australia.

Scientists have called Edgbaston Reserve, which was formerly a cattle station “the most significant natural springs for global biodiversity in the entire basin”.

As well as the goby, the reserve is home to an equally endangered fish, the Red-fin Blue-eye.

Daytime temperatures in the springs may fluctuate up to 21º in a single day. The goby can tolerate seasonal temperature variations between 3º and 39º. Mature gobies are known to live on the bottom of the springs, with young fish preferring shallower areas. During the day they shelter under vegetation.

Edgbaston Goby behaviour

All gobies are similar, with the brightly coloured males featuring a blue, black and white splash on their dorsal fins. During courtship, the male extends its fins and swims with a jerky motion around the selected site. Male Edgbaston Gobies select a site for the females to lay their eggs. This is often a cave beneath a rock or vegetation. Males guard the egg patch until the eggs hatch.

The male guides the female to the site and spawning occurs at night and lasts about an hour. The fish lay between 40 and 100 eggs, which are attached to the roof of the cave or rock. Hatching happens after about 10 days and usually lasts two or three days. The process occurs year round but is less common in winter.

Gobies grow to no more than about 6cm. They seem to disperse between springs during rainfall events. Otherwise the springs are very stable environments little changed by drought, and stable population sizes reflect this.

The Edgbaston Goby is one of five related goby species. It and the Elizabeth Springs Goby (found 400km to the south west) have been ecologically marooned. The other species are distributed through South Australia and the Northern Territory.

Threats to Edgbaston Goby

The chief threats to the goby are livestock, feral pigs and the mosquito fish (Gambusia holbrooki).

Pigs and livestock trample the springs, leading to their degradation, while the Gambusia compete with the goby and the Red-fin Blue-eye, harassing and excluding them from their natural habitat.

Other threats include:

• introduced plants choking the springs
• enlargement of the springs to cater for more watering of stock
• diminished spring flow from water extraction.

The goby is listed as critically endangered on the IUCN Red List of Threatened Species . It’s endangered in Queensland (Nature Conservation Act 1992) and vulnerable nationally (Environment Protection and Biodiversity Conservation Act 1999).

What’s Bush Heritage doing?

In 2008, Bush Heritage bought the 8,000 hectare Edgbaston Reserve, about 40km north-east of the town of Aramac. It had been used as a grazing property, with a pastoral history extending more than 100 years.

Bush Heritage has introduced different types of fencing to control the mosquito fish, pigs and livestock. In May 2016, five volunteers helped us install the first of many mosquito fish exclusion fences.

The fences stop the mosquito fish swimming overland during flooding and invading springs in which gobies live. This fencing is an evolution of older fence styles and is stronger and more durable. As well as protecting gobies, the fences help the Red-finned Blue-eye.

Protective fences surrounding artesian springs help to keep out livestock and pigs.

Without this protection, livestock walk through springs to access the water and eat the plants. As well as trampling the fish habitat, they often defecate where they stand and dig up the ground.