Distressing sight at Moogerah Dam

[sporty1]

Went to fish Moogerah Dam yesterday. It was distressing to see the extent of a "fish kill" that is happening at the moment. Tens of thousands of fish are dead or struggling on the surface dying. The wind is blowing these fish into even more concertrations around the dam wall and from the gorge around to the the boat ramp and smell is overpowering.
Many of these fish look like "boney Bream" in the 15-25 cm range, but there are also numerous large eels, the occasional jewie, and a small number of bass and yellowbelly amongst them. I am not a biologist but it seems that rapid increase of water ( the level has risen from 3% to 8% in a matter of days) has causes the turbidity of the water to increase greatly also and water is now dark brown. The available oxygen in the water has decreased proportionally and as a result the fish are dying from lack of oxygen.
I hope this is the reason because if it is not and more sinister forces are at play then we might have a serious situation on our hands. As I stated it was a very distressing sight to see so many fish in the situation. I hope things settle down soon and we don't see bass and yellas and cod joining the death list.

We met up with 2 guys in a 5m Yatla Marine Hornet with a 100hp 4 stroke yammie on the back (sorry guys didn't get any names) and we both decided to head to Maroon to check out the situation there. On arrival it was obvious that although the water level had also risen it had not done so to the extent of Moogerah. We followed the Park Ridge boys to the sunken weedbeds further up the dam and watched as they proceeded to pull a fish every cast. Gerry and I struggled to land a fish. The Yatla Marine boys could not have been more helpfull in giving us a couple of plastics they were using some garlic scent and a lot of usefull tips and information. As a result we caught some fish and the knowledge we gained was invaluable. Thanks again guys for reinforcing the belief that fisho's are friendly fraternity that are only too eager to pass on help when needed.

I would suggest in closing that the situation at Moogerah be investigated by the relevant authorities just to ensure " a random act of nature" is causing this fish kill. Some form of a clean up of dead and decaying fish is required to avoid further ecological damage as the stench will be horrendous in the next week.
Even so the dam will take months or more to recover from this current situation and the stocking group will need to assess the impact before deciding on a course of action. Have a safe and happy Xmas all.

Murray

[FNQCairns]

Eels!, sad to hear of the kill, still simply the act of the water riseng should't be an issue, moogera from memory is not deep, BOD should be low, turbidity wouldn't be that bad, possible the drought had allowed some long time settled and accumulated nasties to be liberated from sediment ( lake bed) and overand runnoff (topsoil)-long bow though.

Much vegetation get consumed by the rising water, lots of tanin colour you say in the water?

This really shouldn't happen although it could depend on how much wate there was in the dam, could even be water temperature, BB can be a bit like canaries.

Hope the DPI/EPA can be bothered to inform the us of what is going on-really goig on.

cheers fnq

[sporty1]

Hi fnq

the water was a creamy chocolate brown not a tanin tea colour and visibility was zero. The fish were gluping in air on the surface. The water is still 30 feet deep at the deepest section and the level has risen up the bank considerably. The only vegetation covered was short grass on the banks. The dam was down to 3% so to rise to 8% is a significant increase for the previous level. I hope nothing was washed into the dam from surrounding areas. This would be unlikely as there is zero cultivated land upstream. How does one get in touch with DPI or EPA to inform them?

[tunaticer]

I think FNQ is on the money here.......rapid increases in water levels are a natural part of life in our drought and flood environment.

My suspiscion would be runoff contaminants. During the drought and receded waterlines a lot of country has dried out and fertile land become available for both grown produce and weeds. These weeds will have been controlled to an extent by local and state govt authorities in part of maintaining the dams. I suspect that some of these contaminants have accumulated over the prolonged drought and have been released with the 5% increase in volume. Ten years of drought can quite easily accumulate a substantial quantity of contaminants from a wide variety of sources as well as roadside runoff as well. How many contaminants are in an average vehicular crash?? especially when the fire brigade is involved.

Sudden increases in water and turbidity seldom ever have widespread detrimental effects on fauna.

Jack.

[MitchCalcutt]

A Popular cause for fish die off's when it rains is not poisons but something more natural. With a drought that went on for alot longer than usual, a larger build up of dead leafs, bark and everything else that falls off trees, gets washed into the dam in one big rush. Some barks contain the equilivant to soap in them. This takes the oxygen from the water. In a dam thats heavely populated with fish and such a low current % of liveable water in it, there will be casualties. That could explain why maroon hasn't been efected, it hasn't the fish population in it as Moogera.
Mitch

[bass54]

Hi Murry and Gerry,
You are welcome. I am glade to hear that you got some fish after we left. It was a strange bite as they didn't seem to take the soft plastics as much without the scent on it. We may see you out on the water again some time.
Cheers
Jesper.

[sporty1]

Cheers Jesper

catch you around again sometime, merry Xmas to all

[bdm56]

Yeah, was out there too and can say the dam levels have actually gone from 2.5% to 9% in one quick hit.

Very sad sight.

Photos attached.

[bdm56]

Better photos and yes most of the fish were bony bream. In among them were yella's up around 50cm. Very few bass and no large ones (that I saw).

I listen to Breeze FM radio from the Goldy while I travel and they said in news bulletins today that the DPI were warning people not to drink the water because of the health hazard.

Spoke with Robyn up at the caravan park and she said the DPI had already been out there the day before and dragged a lot of dead fish with nets (and that was before i took those photos.

[bdowdy]

holy sh.....t lets pray it doesnt effec t the bass

[Cammy]

so the dam was originally at 2.5% capacity, and then raised to 9%?? that sounds like a very small volume of water, to hold so many fish?

cam.

[bdowdy]

have now heard bass are dying, any one confirm this, fingers crossed that its not.cheers bdowdy..brett

[MitchCalcutt]

so the dam was originally at 2.5% capacity, and then raised to 9%?? that sounds like a very small volume of water, to hold so many fish?

cam.

I agree cammy, that dam has an over population of baitfish for its size. the preditors never could keep a sustainable level of food.
With all those dead fish the oxygen will be sucked out of the water in no time at all, not to mention the efect that disease will have.
Mitch

[tunaticer]

Ummm, 2.5% of the dam may still be quite an expanse of water none the less. Ive seen Glenlyon at 1.5% about 15 yrs ago and it still had a reasonable amount of water remaining to keep quite a large population alive until the rains came.

I still belive that this this magnitude of loss is more then likely a build up of some toxin being released from the incoming rains. Moogerah is still quite close to a lot of areas that could have been exposed to a lot of chemical with all the farming and major freeways closeby. Has anyone done a check on what chemicals have been on transport and involved in accidents on the highways there yet? Been lots of accidents since the last time it was full there.

Jack.

[Big_unit]

Here are some facts -

Typically dissolved oxygen or DO, readings of 2 mg/L or less are harmful and even lethal to fish.

The amount of oxygen that water can hold depends a lot on its temperature. The cooler the water, the more oxygen it can hold and the warmer the water, the less oxygen it can hold

Fish kills are a fairly routine occurence in lakes, dams & etc after inflows where sudden changes water temperature occur.

Nutrient influx can be bad, too many nutrients can cause certain species of phytoplankton to photosynthesize more actively and ultimately reproduce at more rapid rate. This means that the algae or other phytoplankton can block light from reaching further down in the water column. This prevents phytoplankton from living deep in the water column, they need light for photosynthesis. When the algae on the surface die and sink to the bottom, they are decomposed by bacteria. These bacteria consume a lot of oxygen. This limits the oxygen in the deeper waters. As a result of the oxygen depletion, fish and other organisms begin to die.

Nutrient influx can also cause some phytoplankton to produce toxins which cause death.

Its pretty involved once you really start getting down to the real reasons of how Mother Nature works.

Cheers
James