The first step was to find somewhere quiet to lay my fish trap down. Not too far away from the Ormiston College sporting grounds, I found this peaceful little tributary of the main creek in Doug Tiller Reserve, which was perfect.
|Hilliards Creek tributary|
Baiting a mesh cage with vegemite sandwiches (leaving one left over for my lunch), I lowered the trap into the water and left it there for half an hour while I ate. Sitting on a waterside log in the canopy-filtered sunlight was pleasant, and the birds kept me company. I was particularly entranced by an Eastern Yellow Robin (Eopsaltria australis) that fluttered down to the leaf litter periodically to snatch up an insect or grub. I also watched a Striated Pardalote (Pardalotus striatus) dig a nest hole into the stream bank ahead of me, just behind the palm frond seen in the above photo.
|Creek birds - clockwise, top left: Striated Pardalote, Darter, Torresian Crow and Eastern Yellow Robin|
When it was time to pull the trap up, only one fish had swum inside, but I was nevertheless pleased to see it was a native variety and not one of the many exotic species that have infested Brisbane's waterways. A quick consultation of my guide book pointed out the identifying features of a Western Carp Gudgeon (Hypseleotris klunzingeri).
|Western Carp Gudgeon|
Despite being a somewhat plain fish at the moment, male Gudgeons undergo a spectacular transformation during the breeding season, when their scales turn black and their fins become a fiery red. This change presumably aids the female fish in choosing the correct partner for herself, as many Gudgeon species look quite similar otherwise.
A quick sweep of the area with a dip net revealed many Indistinct Shrimp (Caradina indistincta) and a single Mosquitofish (Gambusia holbrooki). As its name suggests, the latter creature is a predator of mosquito larvae, and was introduced from the USA in 1925 to reduce mosquito numbers in urban areas. Overall, the fish has failed to satisfactorily perform its assigned duty and has instead gone on to decimate native fish and frog populations by eating their spawn. I was pleased that a day spent dip-netting and trapping only produced one of these fish, though I'm sure plenty more live in the creek.
Moving on to a section of the creek that resembled an open-ended lagoon, I reset the fish trap hoping to find some different species. Instead, all I found were more Carp Gudgeons, perhaps because I was reluctant to throw the trap too far out from the shore due to snags. Disappointed, I pulled the trap in and threw the remaining bread bait out into the water, only to see schools of small Sea Mullet (Mugil cephalus) arrive and begin to devour each piece.
|Open waters along Hilliards Creek. INSET: Sea Mullet|
Sea Mullet are somewhat misnamed as they can also live in freshwater, as these young fish show. They only reproduce in saltwater however, and huge schools of adults migrate out of the rivers and estuaries each winter to breeding grounds along the coast. The Aboriginal people of Moreton Bay could predict when these migrations would occur, but knew to net the fish only after they'd spawned, thereby ensuring the future sustainability of their harvest.
Our fishing practices are not so wise. On the way back through the reserve, I came upon two young men throwing firecrackers into the water, each one exploding with a loud boom. Because sound travels further underwater, the noise of the explosion can kill every fish along that stretch of water by sending them into severe shock. Disappointed by this total lack of regard for such a beautiful natural area, I reported the incident to the local Police, who will hopefully keep an eye on the area. Having wildlife share our suburbs with us is a privileged occurrence, not a guaranteed certainty, and we must have zero tolerance for such wilful and mindless destruction.