Look who’s just moved in at Mount Burr Swamp!

In some exciting news, the nationally threatened Yarra Pygmy Perch has found its way into the Mt Burr Swamp Restoration Reserve. This has been several years in the making and was given a final push thanks to funding from the Wettenhall Environment Trust.

It’s almost 20 years ago that efforts were set underway to try and protect Yarra Pygmy Perch in the Limestone Coast region through the establishment of refuge populations. Their decline in Mosquito Creek during the Millenium Drought and downward trend across other known locations meant that drastic action had to be taken to avoid the species disappearing from the region entirely. As it stands there are now less than a handful of sites where the species still occurs in the wild, in the Limestone Coast region.

During my time at the (then) Department for Environment and Heritage, Scott Slater and Mike Hammer worked to set up a number of captive populations with local schools and also owners of farm dams. There was always the view that these could be used to seed new populations if the hydrological fortunes of the region took a more positive turn. Whilst that hasn’t happened, wetland restoration at Mount Burr Swamp has bought some some suitable habitat for the species back on line.

With this in mind, we have spent the past 2 years revisiting refuge sites to get a handle on whether these populations have held on, specifically through the incredibly dry period we have just experienced. The good news is that one of these sites is still doing OK.

We also detected a male Yarra Pygmy Perch at Piccaninnie Ponds, which was the first time the species has been seen in this location and the first time we have seen them in the wider Piccaninnie Ponds/Pick Swamp complex since 2015. So aside from knowing we still have some refuge populations going strong, there are also some wild populations hanging on too.

The upshot of this recent dry spell is that it has been an ideal time to really test the resilience of aquatic environments for fish, specifically to check if they remained wet enough for fish to survive. Across the Mount Burr Swamp Restoration Reserve, most of the wetlands dried up last summer, including the main wetland, but there is a dam on the property which didn’t dry out. It is connected to the wetlands during wetter years so if we can establish the species in this drought refuge, they should go forth and prosper across the wider reserve in wetter years. We know from our experience across the border, at Long Swamp, that if you can increase areas of wetland inundation that the species can respond favourably and quickly.

The dam occurs in an area of the reserve still agisted for cattle so there was a little bit of work to get it up to scratch and suitable for holding native fish. This included erecting a cattle proof fence and also planting some vegetation. The fringing areas have responded really well since the cattle have been kept out and we have also planted some water ribbons (Cycnogeton procerum).

With site prep completed, we collected 300 fish from a refuge site nearby and released them into the dam. We will have a better idea on their fate when we re-survey this coming Spring, however we envisage repeated releases over the next couple of years to really cement their ongoing persistence. The funding provided by the Wettenhall Environmental Trust has been instrumental in allowing us to undertake this important first step in what promises to be a positive journey forward for this important and charismatic little fish, that is a feature of NGT’s work in multiple regions of SA and Victoria.

This project was made possible thanks to the Wettenhall Environment Trust