Sooty grunter threat to endangered Mary River cod

[Fitzy]

Qld DPI&F Press release
11 June 2004

Sooty grunter threat to endangered Mary River cod and lungfish

A native north Queensland fish, the sooty grunter, has been captured near Kenilworth on the Mary River, raising fears local populations of endangered Mary River cod and Australian lungfish could be threatened.

Department of Primary Industries and Fisheries biologist Dr Michael Hutchinson said the presence of sooty grunter in the Mary River system was of concern.

He said that the capture of the large sooty grunter specimen followed recent reports of other sightings of the species by anglers fishing near Gympie and Tiaro.

“Sooty grunter are a north Queensland freshwater fish species and are not native to the Mary River,” Dr Hutchinson said.

“It is illegal to stock them both into the river and into farm dams in the catchment.

Dr Hutchison said sooty grunters were an aggressive predator and might compete with lungfish and Mary River cod for food, or even prey directly on juveniles of local species.

The Mary River is part of a recovery program for the endangered Mary River cod and Dr Hutchinson believes unwanted introductions such as this could threaten cod recovery.

“Sooty grunter prefer habitats which juvenile Mary River cod favour as a nursery habitat and lungfish favour for spawning,” he said.

“We don’t know if sooty grunter are able to breed in the Mary River. If they don’t and there are no subsequent illegal stockings of sooty grunter, then they will eventually disappear.

Dr Hutchinson said public waterways could not be stocked with any fish species without a permit.

People wishing to stock farm dams must comply with the freshwater fish translocation policy to prevent accidental escape of non-native species and non-local species into waterways.

Information on which fish species can be legally stocked into farm dams in the Mary River Valley and other areas can be found on the DPI&F Fishweb website at http://www.dpi.qld.gov.au/fishweb/1261.html


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Further information: Dr Michael Hutchison 07 3817 9540
Media Officer: Mark Dawson. Ph: +61 7 5430 4951, Mob: 0407 756 859
Department of Primary Industries and Fisheries Media Unit
PO Box 5165 Sunshine Coast Mail Centre 4560. Ph: +61 7 5430 4911 Fax: +61 7 5430 4994
DPI&F Call Centre 8am-6pm weekdays on local call 13 25 23

http://www.dpi.qld.gov.au/news/NewsReleases/15445.html

[Fitzy]

Just to add to the above, if anyone happens to catch a sooty grunter in the Mary River or any feeder creeks, please destroy it.
I cant think of any other fish native to that system that resembles a sooty grunter however if you're a regular angler there & are not sure what they look like, please look at the pic below for an idea.


Cheers,

Fitzy..

[DRJ]

Fitzy

This is not good news.

Having seen what a small sooty will do in a tank to anything else in it (no matter what the size) then the cod need to watch out.

Hopefully it is only a few renegades that have been released by some fool and they haven't bred (they need at least 25 degrees and rapids to spawn) and that they all get caught before too much damage is done.

Sooties are a great fish - but in the right environment.

Regards
Darren

[flotsum]

This is not the first time these fish have been caught in the Mary River. There have been a few over the years. I was told about five or six years ago when two were caught around Gympie, that a farmer, that I will not name, released a couple of hundred into Yabba Ck in the 70s. A marine biologist I spoke to last weekend says that they seem to be just surviving and will probably die out. It sounded like a boffins reply to me. If these are from the release in the 70s they must be breeding. I don't think they live that long.

[DRJ]

For breeding purposes sooties need a water temp of at least 25 degrees and fast running highly oxygenated waters that create a turbulence - eg they need rapids with higher water temps. These conditions only need to exist for 24-48 hours. They do not guard their eggs once laid so predators could clean a fair number up.

I don't know the Mary but like most rivers or streams in QLD I am sure these conditions would exist somewhere on the river so I would suggest they will breed. The survival rates, growth rates etc may be much lower than up here in the North however if those few fish do enough damage to the cod population you could wipe it out.

If you catch one in the Mary - kill it!!!! Sooties don't just come in black, they can be a light tan through to jet black

If you would like to try some fantastic sooty fishing then try Eungella Dam.

Regards
Darren

[pilgrim]

While I do agree with all that has been said, sooty's shouldn't be there, but I find it a little odd that the Dpi, fisheries would then happily stock Lake Baroon and Borumba with Bass, which are just as predatory as the sooty. While the Mary is at the very upper limit of Bass's natural range, it worries me a little that especially in Baroon where downstream of the dam is one of the last known natural populations of Mary river cod. Don't everybody scream murder at me, I'm not saying we shouldn't stock them there. I just find it a little hypocritical that's all.
The point I am making is A few sooty's in the system is far from the real problem. Clarence River cod do just fine living with the Bass in the Clarence and it's tributary's. As does the Murray Cod as it shares it's habitat with Golden and silver perch, and in some impoundments Redfin. I'ts time we addressed the real problem, and that is siltation of the holes that cod spawn in due to land clearing, building dams in the head waters which reduces the flows and temperature rises necessary for cod to breed. Take a look at the Mary river now, It is a shallow sandy river with very few places for Cod to breed let alone live. Is it any wonder why the few places that they do survive is in places that are difficult to farm, or were locked up as forestry's where the streams still run deep and clean.
I'm not attempting to point a finger at anyone, just saying lets address the real problem.