I SLAUGHTERED my fish - Poisoned them..?? CYANIDE

BuiDoi

..

More for the purpose of discussion and opinion..

In the previous post, I considered that I must have electrocuted my fish as there really was NO other obvious reason..
Vitals all good - I got shocks from the water = Electrocution -- just gotta be... :support:

Quote:

I SLAUGHTERED my fish - Electrocuted Them..

http://www.backyardaquaponics.com/forum/viewtopic.php?f=29&t=24824

the greatly appreciated opinion was that MANY here had encountered similar electric events, without killing their fish, and so whilst the theory of electrocution was plausible, it was not believable by most..

Replacing the failing pump removed the electricity source, and having added even more AIR, I felt - "There can't be any problem now"

Ten dead trout later, I knew the problem was still there.. :upset:

Then I read in a "Trout Manual" about Blue-Green Algae.. and I recalled what I had seen and dismissed..

DISMISS IT ALSO - AT YOUR PERIL

Here is a precis of events..

Quote:

I had a well running system with about 35 Silvers and six salmon..
Basic water cycle values all zero'ish..

I have three clay-ball beds and a raft bed preceded by a shallow bed growing duckweed..

I got some trout fingerlings and sought to add them to the salmon tank.
In anticipation I decided to add salt to 3.5ppt..

Now the theory.. prior to adding salt and the trout, I had seen some bright green powdery algae in the DuckWeed..
AFTER adding the salt, and later the trout, and after about a day, all the salmonoids were dead..
I was prepared to accept Anoxia, as one air stone had pretty much stopped working.. and about fifteen trout fingerlings were added to six salmon..

Next morning all the silvers were dead.. gaping mouthed and flared gills..

There was nothing obvious, but there was the coincidence that the bright green powdery algae was now a dull and dark green, and we had the Sydney cold snap..

I read that the algae was likely Blue-Green Algae.. and it clearly changed after salting and temperature change, and the thought, (found in a trout paper) - the algae died releasing cyanide..

The first lot of trout fingerlings was a small part of the lot from an isolation tank.. Not knowing the cause of death, I foolishly added another ten at lunch time.. at two they ate ravenously and at five, I heard banging as they smashed wildly against the IBC...
I removed then to another isolation tank with a small salt content and lots of air, and they lay on their sides gasping for air and wildly swimming to the surface, gasping air and sinking back to the bottom.. They were is severe distress and all but one died..

So there is my final analysis of what killed the fish.. Only an expensive water analysis would confirm..
but the facets of Algal-Bloom, and death are there and plausible.

Algal Bloom is not the problem - it seems it's their death that is the problem..

NOW - my next dilemma - What happens to CYANIDE.. Does it degrade to an inert substance, given the RIGHT??? conditions :naughty:

, or should the system be completely emptied.. :whistle:

Any Chemists have an opinion..
..
.

Colum Black-Byron

Quote:

gaping mouthed and flared gills

That says to me it was chlorine/chloramines based.

You said you did a major water change, did you treat the water at all? Or just straight tap water.

When I had my kill off with the Murray Cod, I salted too high, then tried flushing it out, dumping the salt, and replaced the water as fast as I could. I started with just pouring the dechlorinator, but it was at 10pm already, I ran out, and next morning, most of them were belly up. Gills wide open, mouths wide open.

We've got high levels of chlorine here, and I'm 90% sure that's what did it.

Also sounds more likely than cyanide.

Gunagulla

Quote:

... the algae died releasing cyanide

What sort of cyanide is formed, HCN aka Hydrcyanic acid?

You can read about it here: http://www.cyanidecode.org/cyanide-fact ... -chemistry

BuiDoi

..
The replacement water was RAIN water..

Gunna.... I have not yet read that reference fully, but ALL I know is what I read in the Trout Paper, declaring that Blue/Green Algae dies and created cyanide.. You could make a FAR better guess than I..
This is also indicated when you read of mass kills in rivers after an outbreak..

Clearly, I am clutching at straws.. I honestly doubt that too many will have experienced the event themselves.. OR.. were aware of it as a possible ..

The DuckWeed was VERY dense in that pond.. I had RINGS with holes to feed Mountain Cloud fish (Now all dead).. the bright green powdery growth was easily scooped out, but I was putting it back into the pond..

I have today thrown a canary in the mine.. I released a trout into the FT..
I could think of no other way of testing what looks magically pristine water..

MurrayH said three parts salt was WAY too high and he only ever used that in an isolation tank and then for up to an hour.. I was sure that trout paper said 3 to 5 was good. and many here think three is good..

Indeed, we are in a post-mortum stage and may never know, save having a frozen fish tested..
..
.

Colum Black-Byron

You can send off a sample of water to have it tested. I'm sure there will be a few around you. No idea about how much it'll cost though.

I'd trust the official trout paper for salting, aren't they supposed to be like salmon that can survive salt and freshwater?

BuiDoi

Quote:

Following the stressor, administer a 1-2% salt flush to the system, In this case, the volume
of the pond is calculated and the appropriate amount of salt deposited at the water inlet of
the pond and permitted to dissipate (usually 1-2 hours are required). The major effect of
this act is to reduce the blood ammonia levels via the increased sodium levels being taken
up across the lamellar membrane.

Quote:

Once the problem is defined, i.e., the major causal factors identified, the next step is to "re-balance" the system.
This is best accomplished by first withholding feed for 3-4 days, if the fish are of sufficient size to permit this.
This will
(1) reduce the oxygen demand of the fish, (2) reduce the ammonia-nitrogen generated by the fish, and (3) reduce the fecal and uneaten solids in the system.
Second, administer sufficient salt (as granulated NaCI) to the system to obtain a 1-2% solution. This will
(1) reduce the blood ammonia/nitrogen levels,
(2) stimulate mucus secretion,
(3) and have an astringent effect on the gill tissues.
Third, reduce the population density to approximately one-half the oxygen-related carrying capacity of the system. This should be accomplished without unduly stressing the fish.

Quote:

The primary clinical sign is, as the common name implies, brown blood. The gill tissues are quite brown, rather than their rich, red color. A blood sample is also quite brown. Methemoglobin levels exceeding 25% are considered clinical, with lethal levels exceeding 50%.
The suggested treatment is 1-2% sodium chloride, followed by high dietary levels of ascorbic acid.
Hypoxia is the clinical term for a reduction of the partial pressure of dissolved oxygen below 90 mm

It must have been something else that suggested 3 to 5 was good, but the above clearly sets a limit at 2.... :oops:

..
.

Gunagulla

Quote:

clearly sets a limit at 2....

That's not 2 ppt, 2% is 2 parts per hundred, or 20ppt!

Also, I think high salinity reduces the amount of Oxygen you can dissolve in water.

joc

Hi Peter, sorry to quash your latest theory about cyanide. Blue-green algae (BGA), or cyanobacteria, do not produce cyanide or release cyanide when they breakdown - it is a misconception due to their name. The 'cyano' in their name is used to describe the blue pigments that they produce and have nothing to do with 'cyanide'. These blue pigments are masked by the green chlorophyll while the algae is alive, just as red and yellow pigments are in leaves only become apparent when the chlorophyll breaks down in autumn. A breaking down BGA scum has some amazingly beautiful blue and purple colours, but the stench is horrendous (rancid butter, smelly armpits, anaerobic sewage - makes me shudder with the memory).

As a water quality scientist I worked extensively on outbreaks of blue-green algae in inland and estuarine waterbodies throughout Victoria and the Murray-Darling Basin in the 1980s & 90s. They can produce neurotoxins which affect the nervous system, hepatotoxins which affect the liver, and skin irritants, even to the point of causing death if ingested in high enough levels either directly through drinking the water (or licking off fur in the case of animals) or eating fish or crustacea which have accumulated the toxins in their systems (it doesn't seem to affect the fish). I have never seen a fish kill associated with toxins from a BGA bloom, however the oxygen deficit from a bloom crashing could potentially cause a fish kill in a confined waterbody. BGA have an advantage over regular green algae in low nitrogen conditions as they can fix nitrogen from the atmosphere, and some species can control their buoyancy taking advantage of limited light in turbid conditions. Normally, if there is high N in the water, green algae will out compete them.

BGA, just like algae, duckweed and other plants respire at night, meaning they use up oxygen and produce carbon dioxide - this can cause an oxygen deficit at night. But it would seem that this is not the situation you are dealing with due to aeration and timing.

Had a random thought - saltwater chlorinators work by electrolysis of chloride ions in the water converting them to chlorine. They run salt concentrations of 3000 to 5000ppm (3-5ppt) which is what you salted your system to, but I am not sure what charge is used - obviously sub-lethal if it is a pool system. Colum suggested that the symptoms looked like chlorine or chloramine poisoning... It is a long shot and I am not sure how plausible it is.

Any luck with finding out if neighbours have had the pest controllers in?

Gunagulla

They would have to be using DC for electrolysis, and I think BD measured AC only... did you flick the MM over and check if there was any DC? - however, I'd think it would be unlikely unless using a DC pump.

joc

Gunagulla wrote:

They would have to be using DC for electrolysis, and I think BD measured AC only... did you flick the MM over and check if there was any DC? - however, I'd think it would be unlikely unless using a DC pump.

Gordon, I bow to your knowledge of things electrical :notworthy:

- definitely not my field

BuiDoi

Quote:

Hi Peter, sorry to quash your latest theory about cyanide. Blue-green algae (BGA), or cyanobacteria, do not produce cyanide or release cyanide when they breakdown - it is a misconception due to their name.

All we, collectively, can go on, is what we read, learn, experience or are told....

I must admit that I would be rather disappointed if CYANO referred to color and not chemical..

the paper was prepared by...
GEORGE W. KLONTZ, M.S., D.V.M. Professor of Aquaculture
Department of Fish and Wildlife Resources University of Idaho Moscow, Idaho 83843

http://aqua.ucdavis.edu/databaseroot/pdf/troutman.pdf

Anything is possible.. I am completely open to ANY possibility, if it means that I and others can learn and avoid such dramas..
I am aware that my situation is complicated by various aspects, most of which Gunna knows about..

Man - it gets confusing with all the terminology PPM PPT %.. anyway - we know that it was 3620PPM on a pool salt meter... and 3.5PPT ( based on 3.5kG / KLtr ) by my expectation (not allowing for what remained in the system from start up salting..

FWIW.. my aqua-canary is swimming around looking for friends..

Thanks for all the different thoughts...

PS - no.. did not test for a DC component...

BTW - 3ppt Salt - that seems to be a NoNo according to the developing opinion...
I know that it smashed the Apple Cucumbers badly..
..
.

BuiDoi

Quote:

“Blue-green algae” describes a large and diverse group of simple, plant-like organisms found in salt water and some large fresh water lakes.

Blue-green algae products are used for many conditions, but so far, there isn’t enough scientific evidence to determine whether or not they are effective for any of them.

Blue-green algae are used as a source of dietary protein, B-vitamins, and iron. They are also used for weight loss, attention deficit-hyperactivity disorder (ADHD), hayfever, diabetes, stress, fatigue, anxiety, depression, and premenstrual syndrome (PMS) and other women’s health issues.

Some people use blue-green algae for treating precancerous growths inside the mouth, boosting the immune system, improving memory, increasing energy and metabolism, lowering cholesterol, preventing heart disease, healing wounds, and improving digestion and bowel health.

Blue-green algae are commonly found in tropical or subtropical waters that have a high-salt content, but some types grow in large fresh water lakes. The natural color of these algae can give bodies of water a dark-green appearance. The altitude, temperature, and sun exposure where the blue-green algae are grown dramatically influence the types and mix of blue-green algae in the water.

Some blue-green algae products are grown under controlled conditions. Others are grown in a natural setting, where they are more likely to be contaminated by bacteria, liver poisons (microcystins) produced by certain bacteria, and heavy metals. Choose only products that have been tested and found free of these contaminants.

You may have been told that blue-green algae are an excellent source of protein. But, in reality, blue-green algae is no better than meat or milk as a protein source and costs about 30 times as much per gram.

NO - It does not sound like there will be ANY cyanide there if it's used medicinally..

How could a scientist make such a stupid mistake..

Quote:

Sickness Caused by Blue Green Algae
Last Updated: Jan 25, 2014 | By Jessica Bruso

Blue-green algae can be either toxin producing or non-toxin producing, depending on the type of blue-green algae. However, you can't tell whether blue-green algae is toxin producing just by looking at it. Consuming water containing toxin-producing blue-green algae can make you sick, as can consuming blue-green algae supplements that contain toxins.
Blue-green Algae in Water

Blue-green algae grows in freshwater that is slow moving, including ponds and lakes. Avoid contact with water containing this type of algae to limit your risk of illness. Depending on the type of toxin produced by the algae, you could get ill from inhaling, swallowing or touching water containing these algae. You should not swim in this water, or use it for drinking, cooking or bathing, according to the Florida Department of Environmental Protection.

Hmmm... confusing - now WHY do they say some may be toxic

and then...
[url]http://www.environment.gov.au/water/quality/publications/factsheet-blue-green-algae-cyanobacteria-and-water-quality[/url]

Quote:

What are the effects of a blue-green algae bloom?

The main effects of blue-green algae blooms are deterioration of water quality and production of toxins by some species. Exposure to algal toxins has been linked to fatalities of livestock, wildlife and pets.

Decaying algae can reduce dissolved oxygen levels in the water column which can severely degrade aquatic ecosystems and lead to the death of aquatic organisms and hence, a decline in biodiversity.

Outbreaks of blue-green algae may have economic consequences from restrictions to the consumptive use of water and recreational activities due to health and aesthetic concerns. Some species of blue-green algae can produce neurotoxins, hepatotoxins, allergens or irritants to the skin and eyes, as well as compounds that affect the taste of water and produce unpleasant odours. In severe cases, the toxins can cause damage to the liver and nervous system and there have been human deaths associated with non-routine exposure to algal toxins through dialysis.

When a bloom is detected, alternative sources of water should be sought for human consumption and domestic purposes until specialised treatment processes can be introduced. Boiling water does not destroy algal toxins and can, in fact, release more toxins as the blue-green algae are killed.

Oh no- so sorry.. Flip a Coin guys... That last was Australian Data... November 2012
..
.

Gunagulla

Algal blooms in lakes and rivers in Australia typically occur in water with lots of fertilser (superphosphate) run-off, and will kill animals due to the toxins and fish due to de-oxygenated water when it all dies off. It is quite common in regional areas around here. One of Tamworth's water supply dams had a bad bloom a few years ago and swimming in it was not allowed for quite some time. I see these cyanobacterial blooms in farm dams quite frequently too, but if your FT didn't look like pea soup, I can't really see it being the cause of the deaths. A few small patches of it amongst the duck weed are, IMHO, not likely to cause a mass die-off.

BuiDoi

..
So... the literature suggests 1TO2% OR 10to20ppt..
Experienced APers say 3ppt sustained, would be hazardous
So it was not the salt level :naughty:

Some literature declares BG algae as edible and healthy, and others say some is really toxic..
So even in a small system, with proportionally small BG algae, could do nothing..?

Some say an electric shock that is significantly unpleasant to us, could be lethal to fish.. others say a full blown circuit to earth would have no effect to the isolated fish..

If only the fish could talk..
..
.

Charlie

I ran my systems at 3ppt for years.

I had a look over your system thread and the first thing that pops out is your stock density. Looks like you have about 400L of wet media and you had 57 fish, 22 of which were oxygen hungry poo machine salmonoids. Unless you have additional filtration I can't see in your pics I'd say you have exceeded your systems capacity by about 30 odd fish. The BOD would have been too great and trout can be finicky in not so perfect conditions and when one dies usually a bunch follow.

Backyard Aquaponics A place to discuss aquaponics

I SLAUGHTERED my fish - Poisoned them..?? CYANIDE

Backyard Aquaponics
A place to discuss aquaponics