Lake turnover a few questions

[RUDD]

If Saprolegnia is causing a problem in a fishery I'd say the real issue was overall management and stocking levels.

Stocking levels are normal. But we are thinking the roach may need fining out as they spawn like mad every year.

The management cant control the weather and the weather has caused the problem.

The lakes are spring feed as the spring water is very cold.

[Latimeria]

What's "normal"? Spring-fed lakes should have extremes of weather moderated by the very fact they are fed from groundwater. Adequate predator populations would prevent an excess of juvenile fish.

[Phone]

Lat,

 

Whilst I sure we are essentially on the same page it is generally accepted "spring-fed" lakes exacerbate the original problem of fish mortality. Rarely, if ever does below ground water (spring water) contain enough oxygen to sustain even a low population, especially if it is at or near 4 C.. Often predators are the first to suffer.

I have never seen the lake in question nor do I have a clue of the limnology. I'd just guess it needs massive aeration if it has a presistant problem. (Fishing would improve also.)

 

Phone

[RUDD]

What's "normal"? Spring-fed lakes should have extremes of weather moderated by the very fact they are fed from groundwater. Adequate predator populations would prevent an excess of juvenile fish.

There are Big Perch, Chub and fish eating Eels (7lb biggest caught).

The pools are in a valley in a cascade style surrounded by a wood.

Spring feed and alot of water passes through.

Even after a few weeks of sunshine cold springwater will continue to fill the pools until ground temp warms up.

It is not the first time Sap has surfaced there.

The EA and independent consultants have come and left scratching their heads as all tests on PH, oxygen and live fish samples have been deemed as normal.

During mild winters the place fishes well and come spring no problems.

After a harsh winter this problem occurs in early spring.

The lakes were chalked a couple if years ago which could explain the amount of gunk this spring as all the rubbish breaks down.

[Phone]

RUDD,

 

See the last sentence in post #9. If spring "turnover" has been eliminated the problem may very well be the "third" type of event.

 

The only instance of (?)[i still can't remember what it's called] I've witnessed of the third type was in these circumstances. In SE Kansas in the 1930's coal strip mining was a big industry. A strip mine was a simple task of removing the top soil under which veins of coal were present. By the late 40's and 50's the "strip pits" (near Pittsburg Kansas) were all full of water and became and still are excellent fisherys.

 

In winters with heavy snowfall, very cold temperatures and a sundary of other conditions CO2 and methane were forced up from the bottom and appeared for the world to be "spring turnover" in the water column. It wasn't. But it was "area selective" in these pits.

 

You say, "There are Big Perch, Chub and fish eating Eels (7lb biggest caught)." This caught my attention. Why do you suspect they (the fish in your quote) are surviving whilst other fish are dying? Usually habitat quality affects all healthy fish equally.

 

I know I've been a pain in the arce on this one but I find the subject very interesting and have spent considerable time with it. Certainly, I can only generalize from 4000 miles.

 

Phone

Edited April 21, 2013 by Phone

[John Weddup]

Edited April 22, 2013 by John Weddup

[Latimeria]

There are Big Perch, Chub and fish eating Eels (7lb biggest caught).

The pools are in a valley in a cascade style surrounded by a wood.

Spring feed and alot of water passes through.

Even after a few weeks of sunshine cold springwater will continue to fill the pools until ground temp warms up.

It is not the first time Sap has surfaced there.

The EA and independent consultants have come and left scratching their heads as all tests on PH, oxygen and live fish samples have been deemed as normal.

During mild winters the place fishes well and come spring no problems.

After a harsh winter this problem occurs in early spring.

The lakes were chalked a couple if years ago which could explain the amount of gunk this spring as all the rubbish breaks down.

 

Sounds an odd one, I'm assuming a natural pH above neutral? Could there be anyone further up the valley doing anything they shouldn't? Even if no-one admits to it,a look on Google maps might be worthwhile, see if there's a land drain feeds into the system. Whch way does the valley face?

Edited April 21, 2013 by Latimeria

[RUDD]

Heard a rumour? No surprise, the best one is a certain fish supplier telling a certain tackleshop that the club with the problem stocked fish from the other well known suffolk fish supplier.

For eight years they have only dealt with the supplier spreading gossip.

Who funnily enough had just stocked the tackleshops own lake.

Covering his arse no doubt!

[RUDD]

 

Sounds an odd one, I'm assuming a natural pH above neutral? Could there be anyone further up the valley doing anything they shouldn't? Even if no-one admits to it,a look on Google maps might be worthwhile, see if there's a land drain feeds into the system. Whch way does the valley face?

There was a problem years ago with pig slurry.

The lakes are surronded bywoodland which is surrounded by farmland.

The bottom pool does not get much sunlight in the winter due to being low in valley, surronded by trees and a low winter sun.

It is this pool where the problem started the first time a few years ago.

[RUDD]

RUDD,

 

See the last sentence in post #9. If spring "turnover" has been eliminated the problem may very well be the "third" type of event.i

 

The only instance of (?)[i still can't remember what it's called] I've witnessed of the third type was in these circumstances. In SE Kansas in the 1930's coal strip mining was a big industry. A strip mine was a simple task of removing the top soil under which veins of coal were present. By the late 40's and 50's the "strip pits" (near Pittsburg Kansas) were all full of water and became and still are excellent fisherys.

 

In winters with heavy snowfall, very cold temperatures and a sundary of other conditions CO2 and methane were forced up from the bottom and appeared for the world to be "spring turnover" in the water column. It wasn't. But it was "area selective" in these pits.

 

You say, "There are Big Perch, Chub and fish eating Eels (7lb biggest caught)." This caught my attention. Why do you suspect they (the fish in your quote) are surviving whilst other fish are dying? Usually habitat quality affects all healthy fish equally.

 

I know I've been a pain in the arce on this one but I find the subject very interesting and have spent considerable time with it. Certainly, I can only generalize from 4000 miles.

 

Phone

A couple of big carp, several small carp, bream, a few roach and a few small roach had fallen victim last time I spoke to the fishery manager.

 

No Rudd, Crucian, Eel, Chub, Tench or bigger Perch.

 

The manager is waiting for EA report on live fish samples taken - from experiance this can take a while.