Native Fish Breeding for Mosquito Control

Viking Kayaks Present the Ozzie with Fishkit 

Stocking groups dabbling in a little fish breeding is nothing new. Some do it as an extension of their activities, some out of necessity to procure unavailable stock; all do it to produce fish for anglers to target, that is, until now.

The volunteers of the Pine Rivers Fish Management Association are well into their first full season of producing Eastern Crimson Spotted Rainbow Fish (Melanotaenia duboulayi), a small Aussie native fish which was widespread throughout the eastern fresh water drainages of south- east Queensland prior to the misguided release of the poorly named, Mosquito Fish (Gambusia holbrooki), in the early 20th Century.

The duboulayi or as they are affectionately known, “Doobies”, only average around 10cm at full size in the wild. So they certainly aren’t a good species to target with your favourite lure but what they are amazingly good at is controlling mosquitoes, unlike the poorly named, Mosquito Fish, which prefers consuming the eggs of our native fish and frogs.

Almost two years ago, at one of the first Bass releases on Lake Kurwongbah, the then Pine Rivers Councilor, David Dwyer, asked if the Bass fingerlings could help control mosquitoes. As David had been very helpful in the lead up to creating the new fishery at Kurwongbah, we felt he deserved a better response than our initial blank stares and we set out to research the answer.

The research highlighted a range of native species which do the job of controlling mosquitoes and the diseases they carry very well. It also highlighted that more than a couple are at risk due to pest fish and ongoing development. This led us to producing a full proposal to develop and staff a breeding centre for these species; with the fish to be used by Council’s pest control staff as an additional tool in their mosquito control arsenal.

Council provided space in an existing depot and a liaison officer with a passion for fish and a tremendous ability to appropriate and recycle used council equipment (the pre-politically correct term would be scrounging) and the Pine Rivers Council’s Native Fish Breeding facility was born and became fully operational towards the beginning of this year and even with missing much of the breeding season, still produced around 5000 fish.

Along the way, Pine Rivers became part of the new Moreton Bay Regional Council, adding more catchments and areas needing to be serviced by the facility. The new council has recognised the benefits of the project and has allocated resources to help it grow and meet this much larger role.

The centre is run on strict genetic and environmental guidelines, producing the appropriate sub form for each catchment and only distributing first generation progeny to private impounded water bodies. These areas are economically unfeasible to treat with chemicals and while the native fish aren’t quite as an effective control as insecticide, once established they continue doing the job year in, year out.

By now, you may be thinking the volunteers from PRFMA are a great bunch of community minded and environmentally sound folk and you would be right. Alternatively, you may also be wondering, “what the hell has this to do with fishing?”

Almost every one of these ponds, dams or lakes in which the small natives are released, can potentially drain into a water storage facility which has a corresponding fishery managed by us or our compatriots at Caboolture. At each distribution day we get to meet the owners of these water bodies, face to face and educate them about the nasty pest weeds and fish which can ruin their dam and possibly be flushed downstream to our water storage facilities, potentially ruining the fisheries which we work hard to produce for your enjoyment.

So in their own, small way the “Doobies” and other species we will produce, are not only helping protect the residents and visitors from mosquito born diseases, they are also helping protect our fresh water fisheries into the future.

Author – Shayne Dumma