Why havent they stocked Somerset with Mangrove Jac

I am about to move out to Coominya which is right in amongst all the dams, I have been an offshore fisherman at heart. But wish to give the fresh water seen a go.

I have fished Awonga dam in Gladstone and the Barramundi are going very well, I think they have also stocked Mangrove jack. But why havent they stocked local Brisbane dams with Mangrove jack ?

I can understand the temperature restrictions with Barramundi, but just the introduction of Mangrove jack or even Sooti grunter would be a great help to promote the fresh water seen.

Its a possibility for the future. They are conducting stocking experiments in the northern lakes at present. Given Tinaroo was/is stocked with them there is absolutely no valid reason to believe Wivenhoe and other SEQ dams won't be. We will have to wait for the experiments to finish before anything takes place down south, probably 4 years. Even then it could be another 4 years before breeding is up and running at 100%, add in another 1-2 years for growth.

It will be awesome when they do arive but it will probably be 10 years before anything happens. 5 at the earliest.

which dams have been stocked with jacks? ???

There only one private hatchery that can currently spawn MJ's and for our more southern impoundments brood stock would have to be obtained from water ways which derive from those impoundments. As far as sooties are concernd im afriad it just wont happen becuase of they just never belonged here indemicly, so if u want sooties im sorry but you might just have to move a little farther north.

or do what i did, turn your old swimming pool into a fish tank and catch sotties and bass wenever you want!!

bobby

p.s. the swimming pool is surrounded by glass and shade cloth so the fish cant get out in floods. ill try and post some pics soon.

do yourself a favour and figure out an efficient way of cleaning it. Did the same thing filled it with bass silvers and barcoo grunter. After a year or so the algae grew to much and we had a serious fish kill, ie all of the buggers. A regular pool filter isn't enough, we used a marine safe flocking agent which kills the algae and sinks it to the bottom, problem is this acts as more food for the next algal bloom and so forth, so basically you have to find a way to physically get the muck out of the water.

There are a number of diferent filter method you could use but the key unit would be a biological filter witch is basically a seperate tank filled with a suitable material such as shade cloth to act as surface area for bacteria to grow and deal with the waste. Algae can be good and bad as the process of photosynthesis and respiration can have an effect on your dissolved oxygen levels, maintaining a Ph of 7-8 is important as it can effect your water chemistry turning amonia into amonium as well as your nitrate - nitrite shifting capacities, stay away from chemical quick cures as these can be toxic to fish and humans. and be warned of the waste managment issues involved. as far as pools are concernd especially heated ones your looking at one of the most ineficient mothods of aquaculture.

so your saying i need a tiny bit of algae in there but not too much? me and my dad wer thinking of buying one of those giant algae plecostimus catfish in there, but i think he might get attaked. maybye my only option is to drain the pool, elaocate the fish temporarily and start again. also, we have just introduced mullet into there, will they help keep the algae down?

thats the jist, i also tried making a biofilter but to no avail. I'm not to sure how effective the catfish will be cause all its going to do is eat the algae and crap it out again leaving almost the same amount of waste.

Have you tried watering your lawn with the hose sucking of the gunk from the bottom? might need motorised pump. old water out, new water in.

Yes draining the pool\pond is required every 9 months ideally, but u could probably get away with once a year and doing so around summer would probaly be better as the nutrients collected during the year would create an algae explosion in the warm weather and might get a bit on the nose. If you can remove the benthic matt, the layer of gunk off the bottom regularily with a modified creepy crawly or such and remove a majority of the physical waste then this will put less pressure on the filter. Maintaining a respectfull amount of turbidity ie suspended particles which in this case is algae achieves a number of things mainly, 1) it provides a means of waste management as it grows it uses nutrients and 2) Keeps the fish calm and less flighty, if you cant see them they cant see u. You can make a simple tool called a secchi disk which is bassically a broom stick marked with 1cm intervals and a white ice cream container lid which u paint black in 2 quadrants of the lid (Like the checkerd pattern on a chess board) Nail the lid to the bottom of the pole so that when u submerge the device lid first you r looking at the checkers, then by slowly lowering the pole till the point where you're unable to differenciate between the black & white contrast you look at the pole to determine youre sechi depth. you ideally want to maintain a reading of between 25-45 cm to suit youre needs. any thing over 50cm and you might want to consider doing a 50% water change. if you have a bit of land at your dissposall with a bit of gradient might i suggest building an artificial wetland below your pool that way you can just syphon the waste water into the wetland where it can naturally be dealt with.

Sorry, I ment to say under 25 cm do A 50% water change, any thing over 50cm Is great.

.

One early thing coming out of the research from Tinaroo is the restriction of where Jacks can be stocked.

There will most probably be an altitude component in where they will be allowed to be stocked.


Richard

i heard that tinaroo is producing legal size mangrove jacks now!!?? can anyone confirm on deny this?

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Originally Posted by Kuhlia_R

There only one private hatchery that can currently spawn MJ's and for our more southern impoundments brood stock would have to be obtained from water ways which derive from those impoundments.

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Dont go betting money on your statements. Any hatchery CAN spawn jacks, I know of several who have, nothing that hard about it. And for broodstock having to be sourced locally (not that that is a problem), well that all depends upon genetic variation, if theres none, then the need in not there.

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As far as sooties are concernd im afriad it just wont happen becuase of they just never belonged here indemicly, so if u want sooties im sorry but you might just have to move a little farther north.

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Theres endemic soots in the Mary River system & some in the goldy region apparently.

fitz

you wouldnt happen to know any exact locations would you fitzy?

l ;D

Fitzy,
I wouldn't go betting on your statement either mate re: endemic sooties in either the Mary or Goldy region - if they are there its due to the midnight stocking brigade and that would not make them endemic (= restricted to a particular region /range) - scientific data re sooties naturally in either of these systems is non-existent, and these regions have been better looked over than most.

Regards - Jim

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Originally Posted by Jim_Tait

Fitzy,
I wouldn't go betting on your statement either mate re: endemic sooties in either the Mary or Goldy region - if they are there its due to the midnight stocking brigade and that would not make them endemic (= restricted to a particular region /range) - scientific data re sooties naturally in either of these systems is non-existent, and these regions have been better looked over than most.

Regards - Jim

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Hey Jim,

ENDEMIC: Native to or confined to a certain region Native CAN mean native to a country or region. A sooty is a native Oz fish, but not natural in the Mary R for eg.

Once a fish is established in a location it may be deemed to be endemic. eg Tilapia are now endemic in Lake Wivenhoe although they are non-native, a pest fish & listed as noxious.

Not implying soots are "native" to the mentioned locations, rather that they are there & are reproducing/sustaining populations. How they got there is another matter, however finger pointing (without evidence) will almost certainly lead to court proceedings as has been seen in the past.

fitz..

yep jacks are getting caught in Tinarro above legal size. The March Fish & Boat showed a beauty cover page, check it out.
Cheers, Mark

Fitzy,

endemic is still the wrong word as your own definition cites 'ENDEMIC: Native to or confined to a certain region' - the word confined pretty well says it - tilapia are not endemic to Wivenhoe - as they are neither native or 'confined' to that region. Certainly know in the scientific sense (or other uses of the word) that sootys are not endemic to the Mary or Gold Coast catchments.

Regards - Jim

Jim do you happen to know a bloke name Kerry.
you and he would get on like a house on fire. ;)
Cheers cloud 9

Kerry who?

and the basis for our relationship would be??

Mangrove jack spawning isn't difficult, but there is a slight problem with actually keeping the juvenilles alive in the very early stages. i think early means about the first 7 days or so. Food is the problem,(possibly because jacks spawn at sea, inshore food sources are not the same) and at present less than 8-10% survival rate of juvenilles is common. "please don't quote me on that figure". Grow out ponds are used in places like Indonesia( i think) where millions of jack larvae are released in hope to gain decent survival rates. the Indonesians produce good numbers of mangrove jack, but from absolute masses of jack larvae. That 10 % figure is similar in their practises.
Once a juvenille jack passes that 7,8 or 9 day age barrier, the survival rates from that stage are much, much better. To gain similar numbers to that of barramundi fingerlings produced at this 10% survival rate of juvenilles(jack), mass projects would need to be undertaken to produce any numbers of jacks to stock our waterways unless the "BREAKTHROUGH" comes soon. Mangrove jacks mature at quite large sizes, and quite often anything smaller than 2 or 3 kg isn't sexually mature. So if broodstock fish need to be collected, i feel "the sooner the better" if projects need to get off the ground. most inshore jacks aren't sexually mature(not always) due to the size and age factor and the fact that the offshore movement of larger fish is evident.
Possibly fishing groups could start a project along the coast , and collect broodstock mangrove jacks and have these fish available to government groups/hatcheries/universities and to make it a priority project. There is a massive call for mangrove jacks in impoundments, and personally i reckon if we produce the broodstock now, they will have time to mature in captivity and be ready for use in the coming years. I have helped kick start the Gladstone Hatchery with jack, many other fisherman have since added to the collection. This has allowed broodstock to be available to fulfill hatchery needs. Some of these fish are now well over 6 kg. Awoonga has had about 8 or 10 000 jack released(locally spawned) compared to over 2 million barra fingerlings. Its a far cry i know, but jack have been caught in Awoonga from these past releases.
NOT 100 % SURE ON THE FACTS/FIGURES I PRODUCED
, BUT I'M SURE YOU WILL FIND IT IS QUITE CLOSE TO THE TRUTH!
Reguards
John Mitchell,
Gladstone
FEEDBACK WELCOME......

um excuse us
but i thought mangrove jacks could only live in salt water
so can they live in fresh water and adapt a bit like the bream up around colleges crossing upper brissy river

thanks :D

Yes Tinaroo and Aplins Weir in Townsville have legal Jacks - Twin Cities Fishstocking Society in Townsville have a permit which is held by DPI to stock 6,500 mangrove jacks per year for 3 years

I'm currious to know if the jacks would ever be able to take hold out at Wivenhoe these days?

Fork-tailed catfish appear to be in plague proportions and some of them are quite large fish?

Would the catfish quickly eat up any small Mangrove Jack fry that were released?

What is everyone's opinion on this?



Louis

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Originally Posted by Louis

I'm currious to know if the jacks would ever be able to take hold out at Wivenhoe these days?

Fork-tailed catfish appear to be in plague proportions and some of them are quite large fish?

Would the catfish quickly eat up any small Mangrove Jack fry that were released?

What is everyone's opinion on this?



Louis

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Yes there are forkies in Big W, but the bass dont seem to have any problems growing & surviving in the place.
No there isnt as many bass as its sister lake, Somerset, but it is over twice the size & since the underhanded way that SIP funds were chanelled away from larger lakes, it is never going to get the stocking density it deserves. In saying that, there is still lots of bass to be found in Big W, just gotta work out where they are.

Jacks would be far better in Big W, both for a greater reward for the angler who puts in the effort & Jacks grow bigger & would eat more tilapia, forkies, banded grunter .......... ;)

Here's a pic from the BASS electric convention recently.

http://www.sweetwaterfishing.com.au/...BASSConv05.jpg