why did all my fish die?

Question

today around mid-afternoon my fish all started swimming at the top of the pond almost sticking their heads out of the water, I thought it was strange but I couldn't do anything about it, in a few hours most of the fish died and now all of them are dead. why?

Answer 1

Yu have gotten some really good answers so far. Ammonia poisoning and pesticide run off are two or the top choices.

Added to that is the possiblity of a problem called "roll over" This occurs during times of rapid heating and cooling and when the top layer of water gets cooler than the bottom layer. When the temperature causes them to flip and then mix, it drops the dissolved oxygen so low the fish cannot survive. This is rare in smaller ponds but a serious problem in ponds over about 1/5 acre. I would recommend calling the county extension service and ask what services they can provide to you in assisting you in finding the problem. They can usually sample and test the water on site for little or no charge.

Best of luck finding and correcting the cause.

MM

Answer 2

you do have a number of good reasons here. More than likely it was from nitrogen poisoning.

When ice off in the spring on ponds starts the breakdown of the leaves and algae that had accumulated from the fall and even winter. The water temperatures are cold which inhibits the rotting of the leaves. When the temps warm in the spring the leaves and dead debris begin to rot. Spiking the nitrate in the pond.

Spring maintenance, even thoughthe water may be really cold is always a good idea. Once the filters are kicked on the pond should be cleaned. Not drained but cleaned of leaves that have found their way into the pond over the winter.

Also, is your pond anywhere near a sidewalk which over the winter was cleared? Salt and salt substatutes could be another culpret here. Unless your pond is where teh runoff from the yard can get to it fertalizers are really not the problem.

Also, over the winter, your fish could have also had little ones prior to hybernating.

Another cause can be, in the fall when the water temps drop below 55 you need to stop feeding these fish completely. Once the temps drop below 50 (water temps not air temps) the fish enter a state of hybernation. Any foods left in their bellies will start to rot slowly building up toxic gasses. When the water warms up in the spring these gasses kill your fish. there is no saving them at this point.

I have been thru all of these when starting my ponds years ago.

I have also gone thru a falty filter. A becket 750 in my 700 gallon pond "leaked" some type of oil or grease into the pond killing most of my Koi within a day. I froze the fish and contacted Becket. The water was professionally tested and in fact the filter was to blame for the fish's death. I had to actually send them the fish and filter as well. They reimbursed me for the cost to replace my fish and gave me a new filter. This is a one in a million shot, but check your pond for anything that looks like oil floating on the surface.

Also, dont bother calling your local fish offices. they will not come out to a personal pond or lake unless you know someone. They will tell you they are busy and it is not their responsiblity. I've tried that too (And I KNOW someone!) Any testing will cost you dearly (around $50 - $100 for a water sample) You are better off finding an independant lab. Personal ponds and lakes are just that personal. Even if the outflow goes into a major stream. Even the fish authorities have no jurisdiction over them.

If I can be of further assistance please feel free to email me.

Sorry to hear about your fish.

Answer 3

You did say pond,I think. The coming to the surface symptom could mean low oxygen content,high bio-chemical oxygen demand,(lots of rotting stuff),high ammonia content,(something killed or overloaded the bacteria),or this time of year a lot of ponds are wiped out by lawn chemicals running into water systems. What sort of aeration do you have? The nitrifying bacteria need oxygen to operate. Have the water tested before adding more fish,and give the pond some time to cycle.----Good luck finding the cause,--------PeeTee

Answer 4

I think I have read somewhere that if that happens the fish might not have been getting enough oxygen in the water....was all the aeration equipment working properly?

Answer 5

This happened to me when a neighbor fertalized her lawn. The chemicals washed off the grass into my pond and killed all the fish.
Same thing happened to a friend of mine when they had the yard sprayed for insects. Pesticide washed off the yard and into the pond.
I've also heard of people deliberately poisoning ponds. All sorts of chemicals can be dumped in with fatal consequences. Why? Because they are mean. Maybe a neighbor hated the sound of the foutain and decided to destroy it. (also happened to me)
Take a sample to a pet store, some things show up on aquarium tests. If possible send a sample to your local agriculture department. They do testing cheap or free. Call them for details.
Sorry for your loss.
Good luck

Answer 6

It's hard to say exactly why without doing various water tests. Was your aquarium cycled? Did you not change the water in a long time? If you haven't dumped your water yet, take a sample and bring it to your local pet shop. If you are a regular they might do free testings, or they might charge a small price if they do a lot of extensive tests.
If you plan on keeping fish seriously, you should invest in various tests you can do yourself. It should include at least: ammonia, nitrite, nitrate and pH.

Answer 7

the most likely cause is a break down in the nitrogen proccessing cycle in the tank, ammonia went way up and burned the fishes gills and limited thier ability to process oxegen, so they gulped for air to no avail

a less likely cause is poisoning whitch can cause a similar effect.

my suggestion is empty the tank and start all over with new water and let it cycle for a good week before adding anything to the tank

having kept tropical fish for most of my life and having dropped hundreds of dollars on single fish, having worked in aquatics retail, wholesale and spawned some rare fish

i can tell you that it happens, fish die, tanks crash, and lessons are learned that way, dont give up, just be more careful in the future

good luck

Answer 8

OH MY GOD! Are you sure the water temp. is right?! CHECK NOW! If its fine talk to someone before getting more fish!

Answer 9

we need more info on the quality of ur tank water.
all the fishes showed signs of hypoxia.
lack of oxygen content inthe water.
something made the dissolved oxygen in the water diffuse out quickely.
was there oil in ur water?

Answer 10

maybe it was there time to go or maybe it was the was the food or temp in the water