Does bottom detritus and decay heat ponds like compost? (LONG THREAD)

[Wayfarin]

Hello, folks!

As I've mentioned on other threads, I'm hoping to upgrade my RES turtle to an outdoor pond enclosure.
I've been researching the natural habitat of aquatic turtles for information I may need to replicate her ideal living environment.
One thing I always come across is the fact that red-eared sliders are usually restricted to water bodies with soft, muddy substrates.

I figured the reason for this was simple. Turtles, like frogs, bury themselves under the mud and detritus prior to brumation.
However, I had never actually given much thought to the reason for this.
It would figure that the bottom substrate would be decent at insulating. However, turtles (and frogs) are cold-blooded, so they don't generate any internal body heat. Therefore, they don't have much heat in their bodies to insulate under the substrate. And since heat rises to the surface of the pond, it would figure that the bottom wouldn't be the warmest place in the pond.

Yet it is the surface of the pond that freezes over. Even when the temperature is -20 degrees F the pond sediments in the shallows are sometimes unfrozen.

Most interesting is one of my personal observations. We have a large river in our town with flowing water. It isn't a rapid, but it isn't stagnant either. In the winter, the river freezes over almost entirely. Yet on one of our walks through the forest, I noticed that there was a small ditch-like creek. It was unfrozen. Yet it was less than 6 inches deep!
The only logical explanation I could think of was the fact that the creek had a very deep substrate of leaves, mud, and detritus.
The river bottom, on the other hand, is presumably made up of gravel and small stones.

I've just been researching composting, and I came across something called "hot" composting. Apparently, heat is generated within the compost piles by certain bacteria and fungi.

I can't help but wonder if there is some connection between "hot" composting and brumation. Sure, hiding under the mud also gives them privacy and protection from predators. But could there be another reason why detritus is important for turtles and frogs?
Is there any difference between decay out of water and below the surface?

Could this mean that muddy bottoms are partially responsible for keeping ponds warm in the winter, and overheating them in the summer?

Any input would be appreciated. Thanks! God bless!

 

[GBBUDD]

it would figure that the bottom wouldn't be the warmest place in the pond.

but the bottom is generally the warmest part of a pond that's why we add aeration only toward the top of the water like a foot deep. the cold surface waters act like insulation and down below your local frost line soil temps are an average around 50 degrees and don't really change much.

 

[Laaf]

When I have scooped out leaves and muck from the bottom of my less than 2 foot deep pond, indeed it felt warm in my hands compared to the water temps. It was leaves and whatever fell down and had that black muck,sewery smell too.

 

[Lisak1]

All decaying material produces heat where it's able to - that's how it breaks down. If it stays cold it won't rot. That's why the bottom of the compost pile will break down even in the coldest weather but the top stays pretty much intact.

 

[Jhn]

Detritus and mulm on the bottom isn’t necessary for brumation of turtles, they really just need caves or place to go under (like logs)to feel secure. The issue in our ponds is going to be the cold water and our ponds aren’t that deep, even 5’-6’ deep you don’t get much stratification in temp., so the detritus and mulm won’t decay like it would in nature in deeper ponds, thus generating little heat for the turtles.

 

[Wayfarin]

Detritus and mulm on the bottom isn’t necessary for brumation of turtles, they really just need caves or place to go under (like logs)to feel secure. The issue in our ponds is going to be the cold water and our ponds aren’t that deep, even 5’-6’ deep you don’t get much stratification in temp., so the detritus and mulm won’t decay like it would in nature in deeper ponds, thus generating little heat for the turtles.

Based on what Laaf and Lisak1 said in their former comments, I think that how deep the organic detritus is matters more than the pond being a certain depth, although ideally, the amount of organic matter it would take to actually significantly heat a pond would probably suffocate the majority of the organisms other than microorganisms and hardy macroinvertebrates. Since decay-causing organisms use a lot of oxygen, I'd imagine that hydrogen sulfide would be a risk in a small pond.

Also, I'd imagine that turtles would only brumate in caves or under logs in warmer regions. Where we live, painted turtles inhabiting a small pond apparently brumate underwater in relatively shallow water (probably no more than 6' deep, but perhaps deeper) when the temperatures above the surface drop down well below 0 degrees F, even in ponds that barely receive any sunlight. Since there is a dense canopy of trees above the pond, I'd imagine that the bottom detritus in the shady pond is vital for their survival.

 

[Wayfarin]

Detritus and mulm on the bottom isn’t necessary for brumation of turtles, they really just need caves or place to go under (like logs)to feel secure. The issue in our ponds is going to be the cold water and our ponds aren’t that deep, even 5’-6’ deep you don’t get much stratification in temp., so the detritus and mulm won’t decay like it would in nature in deeper ponds, thus generating little heat for the turtles.

Would there be any way to allow a red-eared slider to brumate in a pond only 18-24" deep in a region that drops below 0 degrees F? We don't seem to have any outdoor electricity, but we might be able to utilize electricity somehow.

 

[GBBUDD]

Would there be any way to allow a red-eared slider to brumate in a pond only 18-24" deep in a region that drops below 0 degrees F? We don't seem to have any outdoor electricity, but we might be able to utilize electricity somehow.

solar pump there are units that will push 1600 gph 24/7 as they have a battery and run the pump and charge for the evening

 

[Jhn]

Based on what Laaf and Lisak1 said in their former comments, I think that how deep the organic detritus is matters more than the pond being a certain depth, although ideally, the amount of organic matter it would take to actually significantly heat a pond would probably suffocate the majority of the organisms other than microorganisms and hardy macroinvertebrates. Since decay-causing organisms use a lot of oxygen, I'd imagine that hydrogen sulfide would be a risk in a small pond.

Also, I'd imagine that turtles would only brumate in caves or under logs in warmer regions. Where we live, painted turtles inhabiting a small pond apparently brumate underwater in relatively shallow water (probably no more than 6' deep, but perhaps deeper) when the temperatures above the surface drop down well below 0 degrees F, even in ponds that barely receive any sunlight. Since there is a dense canopy of trees above the pond, I'd imagine that the bottom detritus in the shady pond is vital for their survival.

Granted in my area in recent years it has been relatively mild, but there are years past we regularly get down below zero in the winters. Even then I had turtles brumating under logs and in caves, I have an area of my pond that is one huge lily planter, that has about 4-6” of sand and detritus down there, have yet to have a turtle that I am aware of brumate in there. It may depend on the species of turtles, but the ones I keep tend to brumate under logs and in caves.

 

[Jhn]

Would there be any way to allow a red-eared slider to brumate in a pond only 18-24" deep in a region that drops below 0 degrees F? We don't seem to have any outdoor electricity, but we might be able to utilize electricity somehow.

Good question, I have never kept red ear sliders, painted turtles would make it in a pond like you are describing, but they are incredibly hardy, I have seen them crawling around pond bottoms under ice cover in the middle of winter.

@Stephen Noble has kept red ear sliders for a long time, would let him chime in on this. As I don’t want to give advice on a species of turtle I have no experience with.