What effect do consecutive frosts have...

Do consecutive frosts have the same effect as a single frost?

I mean for example, its a sunny cold day (like yesterday) thenlast nightits a clear sky and we got a frost, then today its exactly the same, bright sunny and cold, then again another frost tonight for the 2nd night in a row...

What effect on fishing will a 2nd straight frost have?

On a deep stillwater 10+ ft very little. On a shallow water a great deal. Water is a very bad conductor of heat andtakes a long time to warm or cool down. Deep waters at this time of year are pretty constant in temperature 42-46 F. Shallow ones can vary widely particularly if you get a wind with the cold temperatures, which mixes the water up.

A second frost during the night after the first frost will tend to lower the water temperature further, provided the maximum temperatures during the first two days are roughly the same.

After two consecutive frosts I've fished tonight and had a 5lb barbel...result!!

Im a believer that if the air pressure stays constant then no effects on two nights offrost

Having said that, there was a bit of water in the river and a nice drop of colour....

I reckon that it takes a while for temperature drops to affect the river, especially in the deeper areas where the fish are laid up; conversely, it takes a while for a warm spell to impact on the water temperature (pure theory as I have never been one for taking water temperatures).

Not sure on how the thermoclime principle relates to running water, butI should imagine thatits a lot more complex than you think; for instance, for some distance below a weir you would expect the effects of warmer or colder weather to have a quicker impact due to the mixing of the water in the weir pool (am I making sense?)

Tony Thermoclines don't happen on running water and on deep stillwaters (waters over 20 ft deep) where they do happen, they only occur in the summer months.

I can see the logic of your thinking re river and weirs but it's not totally correct.River temperatures are acomplexmatter, but as a rule of thumb, they are more or less the same temperature from the the upper midsection down to the estuary. The upper zone on the hills, the temperature will generally be colder that the mid section simply because the hills are a colder place for much of the yearthan the lowlands.There may be a short period of time during the high summer when the two are equal. And that is only likely where the head of the river leaches out of bogland. If the headof the river starts from a deepunderground aquifer the waterleaving it is going to be much colder (between 42 -50 F) than the surface source head.

In the winter the opposite is true. The aquifer water is still between 42-50F, as the water temperature in aquifers doesn't vary much, a couple of degrees F at most. But the bog water may be nearfreezing, 34-38 F,for much of the winter.

By now you kinda get the picture of the complexity of it and I've not even factored in warm and coldrain, heat island effects of discharges from towns and cities, other discharges from lakes, reservoirs and so on.

<blockquote class=quoteheader>The bad one wrote (see)</blockquote><blockquote class=quote>

Tony Thermoclines don't happen on running water and on deep stillwaters (waters over 20 ft deep) where they do happen, they only occur in the summer months.

I can see the logic of your thinking re river and weirs but it's not totally correct.River temperatures are acomplexmatter, but as a rule of thumb, they are more or less the same temperature from the the upper midsection down to the estuary. The upper zone on the hills, the temperature will generally be colder that the mid section simply because the hills are a colder place for much of the yearthan the lowlands.There may be a short period of time during the high summer when the two are equal. And that is only likely where the head of the river leaches out of bogland. If the headof the river starts from a deepunderground aquifer the waterleaving it is going to be much colder (between 42 -50 F) than the surface source head.

In the winter the opposite is true. The aquifer water is still between 42-50F, as the water temperature in aquifers doesn't vary much, a couple of degrees F at most. But the bog water may be nearfreezing, 34-38 F,for much of the winter.

By now you kinda get the picture of the complexity of it and I've not even factored in warm and coldrain, heat island effects of discharges from towns and cities, other discharges from lakes, reservoirs and so on.</blockquote>


Ther's always a danger of making a tw*t of yourself when you start discussing things that you have little knowledge of!

I don't mind though because I now understand a little bit more about the river than I did before, thanks to your excellent reponse Bad One/forum/smilies/smile_smiley.gif(the moral of this is don't be afraid to ask stupid questions!!/forum/smilies/wink_smiley.gif)

Still need to understand more about the effects of environmental factors on fish, particularly with respect to locating them and their propensity to feed.

Anyone know of any good reading or articles online that deal with this important aspect of angling?

This is very interesting and im glad i asked now.

Tony you dont look like a tw@... not at all.

on a pond which temp is more important thermocline or hypolimnion

<blockquote class=quoteheader>Day Breamer wrote (see)</blockquote><blockquote class=quote>

This is very interesting and im glad i asked now.

Tony you dont look like a tw@... not at all.</blockquote>
Nice of you to say so Day Breamer/forum/smilies/nerd_smiley.gif

Tony you haven't made a T**t of yourself, far from it. You'd clearly given it a great deal of thought based on your limited knowledge and understanding. You'd worked it out based on the information and knowledgeyou had.

Had that information and knowledge been correct, and you clearly weren't to know it wasn't, the assumption would have been right.No shame or disgrace in that at all.

For the thinking process I'd give you 8 out of 10, even though the conclusion wasn't correct.

Thinking anglers always, in my experience, catch more fish than the robotic type.

As for this "Still need to understand more about the effects of environmental factors on fish, particularly with respect to locating them and their propensity to feed." That is a big subject /forum/smilies/smile_smiley.gifNo one that I know has ever wrote a book about it, and it would take a book to do it justice. It would be very dry and heavy reading as it would have to enter the world of academia, science along with being entertaining from an angling view point. I think that fact alonewould put off many publishers of angling books publishing it.

Distilled down into a simple form for rivers, fish them when the river temperature is rising during the winter months. And if it's cold, 3-5 days into to such a snap and go for the chub.

On stillwaters both winter and summer get on them if there's a good blow and fish into it or side on to it down towards the windward bank.

"on a pond which temp is more important thermocline or hypolimnion"

Neither, as they are physical states of water. They are physical layers caused by deep water warming up. I have to say it's one hell of a pond if it stratifies. As stratification is normally associated with large deep waters,meres, lakes, reservoirs and the like.

If what you were asking is which layer is best to fish in on a deep stratified waters in the summer? Then the answer is the epilimnion. And fish it from the windward bank or as near to it as you can.

The reason you need to fish in this layer is twofold -

1 Wind tilts the stratified layers and on the windward bank with a good blow on, the epilimnion can be tilted rightdown to the bottom.

2 In the hypolimnion there is very little dissolved oxygen and fish just don't go in areas where there's little oxygen.

Let me repeat again, for water to stratify into what people call the thermocline the water needs to be more than 20 ft deep and stratification only take place during the summer.

Where true stratification takes place there are 3 layers, hypolimnion (bottom layer), thermocline (middle layer)epilimnion (surface layer)

I remember wading out from a lee shore during a strong wind on Sterkfontein, a huge man made reservoir with depths down to 70 metres.

The air temperature that day was about 28 deg C but the water was so cold it made me gasp. A typcal example of the tilting of the thermocline.

There were no fish along that part of the water either.

The bad one thanks for explaining that.

Richard Walker first popularised the concept of the thermocline in Still Water Angling published in the 1950's. Before then it was probably only referred to by fishery scientists and biologists. In a later edition of his book he added a footnote. He said that anglers had assumed that they had to contend with the thermocline in every sort ofpond and lake. He explained that it only occurs in large lakes or reservoirs with depths in excess of 15 or 20 ft.

In my view, the average angler can forget about the thermocline unless he fishes large lochs and reservoirs. If he does fish these types of water, then the thermocline is only present from late spring to autumn.

The Angling Times regularly gets its facts muddled about the thermocline. Articles sometimes wronglysuggest thatit's present in small shallow ponds and it exists throughout winter.

It's true that in small shallow waters on hot still days, the surface layer of water can be a bit warmer than the bottom layers. But this simple stratification isn't the same as a thermocline.