Feral fish & fencing at Yourka

Guest bloggers
Published 19 Dec 2019 
by Peter Johnson 
about  Yourka Reserve  
Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.<br/> Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.
Herbert River on the reserve boundary. Photo ANGFA Qld.<br/> Herbert River on the reserve boundary. Photo ANGFA Qld.
Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.<br/> Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.
Most of Sunday Creek is dry at this time of year, but a few reaches still hold water. Photo ANGFA Qld.<br/> Most of Sunday Creek is dry at this time of year, but a few reaches still hold water. Photo ANGFA Qld.
Glass perchlets (Ambassis agassizii) from Sunday Creek. Photo ANGFA Qld.<br/> Glass perchlets (Ambassis agassizii) from Sunday Creek. Photo ANGFA Qld.
Feral Tilapia from Sunday Creek. Photo ANGFA Qld.<br/> Feral Tilapia from Sunday Creek. Photo ANGFA Qld.
At Good Gully electric fences have been erected to keep feral pigs and stray cattle out of the waterholes. Photo ANGFA Qld.<br/> At Good Gully electric fences have been erected to keep feral pigs and stray cattle out of the waterholes. Photo ANGFA Qld.
Jet, Noah (Pete’s son) and Pete (L-R) with the repaired fence.<br/> Jet, Noah (Pete’s son) and Pete (L-R) with the repaired fence.

I’ve had the privilege of visiting Yourka reserve three times over the last five years. The first was in the winter of 2015 for an overnight visit to celebrate the establishment of a nature refuge over Yourka and funding for a set of projects to help Bush Heritage with managing the reserve.

The second was in the spring of 2016 to undertake some informal aquatic surveys of Yourka’s beautiful wetlands and waterways.

Most recently my son and I spent a week volunteering which, for mid-November, felt a lot more like summer than spring.

Over the years the results of the Bush Heritage commitment to practical land management have become more evident. Stands of weeds like Lantana and Siam Weed have been removed or subdued. Feral pig numbers have been steadily reduced and the impacts of stray cattle brought under control. The reserve manager, Paul Hales, has laboured hard to maintain a network of tracks and firebreaks so that controlled burns are well managed and the risk of wildfire, especially during such a hot, dry start to the season, are kept in check.

Native grasses have recovered from grazing and flocks of finches take advantage of the return of seed throughout the reserve. By day cockatoos, rosellas, and lorikeets add splashes of colour to the canopy and at night the calls of Curlews, Nightjars, and Tawny Frogmouths fill the air. In my most recent stay we were lucky enough to see a Rufous Bettong near Sunday Camp and a Freshwater Crocodile in Rocky Waterholes (they’d previously only been seen in the Herbert River on the reserve boundary).

I have a personal interest in fish and wetlands. As a kid I spent a lot of my spare time with my feet in the mud.

Yourka has beautiful Eastern Rainbowfish, Purple Spotted Gudgeons, and Spangled Perch throughout its waterways, as well as Flyspecked Hardyheads, Olive PerchletsMidgley's Carp Gudgeons, Sooty Granters, Hyrtl's Tandan and probably others in some locations.

Also among the fish at Yourka are some ferals, noxious Gambusia (AKA Plague Minnow) and Platies. Both of these feral species occur in the lower and mid reaches of Sunday Creek, especially where there was evidence of long-term disturbance from pigs and cattle removing aquatic vegetation.

A year after my second visit to the reserve I got a call from Paul describing a fish he’d seen for the first time in Rocky Waterholes. Unfortunately I had to tell him the description matched Mozambique Tilapia a noxious fish that's become widespread in eastern Queensland.

Last year Tropwater confirmed that Tilapia had spread further through the Herbert River. Unfortunately, during my visit this year we found Tilapia had also invaded the lower and mid reaches of Sunday Creek. As with the Gambusia and Platies, Tilapia showed a strong preference for disturbed wetland areas.

Surprisingly, despite the invasion of another feral fish, even the waterholes with the most Tilapia had seen an increase in the diversity of native fish. Paul’s efforts in reducing the impacts of pigs and cattle could be seen in the recovery of the wetland vegetation that provides habitat for native fish.

During this visit we worked with Paul and Jet (another volunteer) to modify the electric fence that helps protect waterholes in Good Gully; we built and fixed fences and flood gates near the boundary of the reserve to make it easier for neighbours to muster their stray cattle; and we helped with daily checks of feral cat and pig traps.

It’s very easy to get caught up in pictures of cute and cuddly wildlife but some of the most important work the Bush Heritage staff do is the day-to-day protection of the reserves and habitats that wildlife is dependent on. It’s not glamorous work, and sometimes it’s hot, dirty, and just plain hard. If however, if you're able and you get the chance, giving some of your time to an organisation that’s protecting nature for the future of all Australians can be extraordinarily rewarding.

Herbert River on the reserve boundary. Photo ANGFA Qld.<br/> Herbert River on the reserve boundary. Photo ANGFA Qld.
Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.<br/> Craterocephalus stercusmuscarum (Flyspecked Hardyhead) and Melanotaenia splendida splendida (Eastern Rainbowfish) from the Herbert River. Photo ANGFA Qld.
Most of Sunday Creek is dry at this time of year, but a few reaches still hold water. Photo ANGFA Qld.<br/> Most of Sunday Creek is dry at this time of year, but a few reaches still hold water. Photo ANGFA Qld.
Glass perchlets (Ambassis agassizii) from Sunday Creek. Photo ANGFA Qld.<br/> Glass perchlets (Ambassis agassizii) from Sunday Creek. Photo ANGFA Qld.
Feral Tilapia from Sunday Creek. Photo ANGFA Qld.<br/> Feral Tilapia from Sunday Creek. Photo ANGFA Qld.
At Good Gully electric fences have been erected to keep feral pigs and stray cattle out of the waterholes. Photo ANGFA Qld.<br/> At Good Gully electric fences have been erected to keep feral pigs and stray cattle out of the waterholes. Photo ANGFA Qld.
Jet, Noah (Pete’s son) and Pete (L-R) with the repaired fence.<br/> Jet, Noah (Pete’s son) and Pete (L-R) with the repaired fence.