What is everyone up to at the moment?

[garylee]

Yesterday started off looking like a blank, did a little trot round the lake to see what was happening, gave time for the fish to find the feed. Then finished with a half dozen small carp and perch (about the 1 lb mark) and tiddlers just using the whip rod. Mind you it did get chilly, so started to keep an eye out for a Weddup turning up!

Where did you fish wunnus ?

[Steve Burke]

Dales,

 

It seems to me from a logical view that light has to be the trigger. Remember, in still(ish) water over about 8 - 10 feet the temperature is ALWAYS at or near 39F.

 

Phone

 

Phone, I totally disagree that the temperature is always at 4C/39F in these depths. If so all my textbooks and many of my temperature readings over many years are totally wrong!

Edited April 11, 2013 by Steve Burke

[garylee]

 

You would be surprised how quickly the margins and shallow area's warm when either the sun shines or air temps are above water temp and the wind blows.

Yes John I made myself a thermometer that I could cast and it was quite an eye opener the rise in temperture on some of the bars at Barham and Causeway when the water is clear and the sun shines.

[Phone]

Steve,

 

You must be misunderstanding my statement. It is basic science. Your textbooks will say the same. Water achieves its maximum density at roughly 4C (39f). That is, water (including ice) at all other temperatures below or above 4°C is less dense. Any water that is 4C will be found at the bottom of the lake. This unusual behavior with WATER is important to freshwater fish, plants and animals that exist in climates where water freezes in the colder seasons of the year. You're right if you are saying liquids become more dense and they become colder. That it true of everything but water. If it were true of water ice would form on the bottom of a lake.

 

I don't know tench but if they winter on the bottom then my "logic" would say they are most affected in the spring by light. Of course, the water on the bottom of a lake in the summer is also 4C in most cases.

 

There are external forces that can change the stratification i.e. wave action. But the the heaviest water, 4C, will be on the bottom.

 

Phone

[Steve Burke]

Phone, I assure you I do understand about water at 39F/4C being at its heaviest. In fact I've posted just that on the Forum many times over the years

 

What I dispute is that water at a depth of 8 to 10 feet is ALWAYS (your caps) at or near this temperature. This simply isn't so. In summer it's way above that. In fact it probably doesn't go down that low then in the UK in any but the deepest waters. Even in Lake Wintermere in the north of England the temperature in a typical July is still 6C/43F as far down as 60m/200ft. Even at 33ft/10m it's typically 54F/12C. And at 10ft/3m it's above the thermocline and typically 59F/15C. (Source: Life in Lakes and Rivers by McCann and Worthington).

 

It's not even so in winter here. Bear in mind that in the south of the UK winters are a lot warmer than yours with many waters remaining ice free all year in mild winters. Yes, the temperature at great depths (if present) may be only 39F/4C, but not at 8 to 10 feet. Here I've measured 46F/8C myself.

Edited April 11, 2013 by Steve Burke

[Phone]

Steve,

 

Ahh-ha! it is the 8 to 10 ft you dispute. Very well, I'll correct myself - but only slightly. Water temps in "isothermal" lakes can be/are 4C year around. Otherwise, even with sunshine the deeper the colder and stratification with 4C ending up on the bottom. I would bet money, marbles or chalk that most lakes/ponds in the UK are lakes with a epilimnion, metalimnion and hypolimnion. If that's the case the bottom water is 4C without any other force interfering. Remember red, green, then blue light are dissapearing at a constant rate.

 

What I've never had answered and often pondered is if you have 3C and 5C which would be closest to the surface. If they mix it becomes 4C (maybe?) since one has to go through the other.

 

BTW, how do you measure the temp of angling water at the deepest point? Just because you've done it for years doesn't mean you've done it "right" for all those years.

 

Phone

[Steve Burke]

Phone, most lakes that are fished for our coarse species in southern England are too shallow to stratify and so don't have a epilimnion, metalimnion and hypolimnion.

 

Your second point is an interesting one and I don't know the answer. As you say, presumably they would mix.

 

The temperature was taken on a slow acting thermometer on a line and left long enough to register. Readings were taken at various depths, not just on the bottom.

 

Returning to the first point as this is relevant to a lot of other matters as well, you need to bear in mind that our waters, let alone our methods and weather conditions, are very different indeed to yours. What applies in one country may not in another.

 

Having said that, I've learned a huge amount from US anglers over the years. In many areas, especially lure fishing, you're way ahead of us. In others it's the opposite.

 

You may have read it before, but in case you haven't here's a link to an article I wrote many years ago comparing British and American angling: http://www.anglersnet.co.uk/Miscellaneous-Articles/british_american_angling.html.

[Phone]

Dales,

 

Now look what you've done! You've got me into a pi$$ing match with one of the most esteemed members on AN.

 

Steve,

 

I remember that article very will. However it sticks in my mind for a reason you would never guess. The definition of "stringer".

 

I can't find any evidence your water is different from any other water in the world from a scientific point of view. Water stratifys in a one litre beaker. Here's a UK site that pretty well says what I am saying. http://www.lifeinfreshwater.org.uk/Web%20pages/ponds/Abiota%20Ponds/Temperature.htm

 

Phone

[Dales]

Dales, Now look what you've done! You've got me into a pi$$ing match with one of the most esteemed members on AN.

It's of your own making :-)

 

In accountancy we have just 2 important questions to ask when people start number crunching and producing conclusions or theories.

 

Do you stand by your figures?

 

If you answer yes, then the next question is prove it.

 

If the answer is no, you are politely told to shut up.

[Steve Burke]

Whilst I was correct in pulling Phone up about water at 8 to 10 feet always being at 4C, he's right about pulling me up about stratification.

 

Phone's post prompted me to do some research on the internet on this. Previously I had relied on my biology textbooks and they're wrong! More recent research shows that thermoclines do occur in shallow lakes. In fact I found a recent paper that nicely showed this. See http://www.limnology.ro/water2012/Proceedings/002.pdf.

 

So Dick Walker's assertion in Still-Water Angling wasn't incorrect after all, even though in later writings he modified it! I suspect that, like me, he too got his data from biology textbooks.

 

However Phone is still incorrect when he says that the bottom water is 4C without any other force interfering - unless of course he means sunlight! Only in extremely deep waters would this be the case.

 

Nonetheless, the reason I gave for this was also incorrect, and for that I apologise.

 

The best thing of all about this discussion is that I've learned something new. Not only is it interesting in itself, but it will probably help me in my fishing.