Lancashire,
United Kingdom 
I have a number of newts in my pond each year but the pond is leaking. I tried to repair but need to empty it and reline. I will do this in Late October/November. There is a large amount of sludge at the bottom of the pond. How can I best assure that anything hibernating in the sludge is catered for?
16 Aug, 2020
Answers
Why not do it earlier? The newts will be fine in the garden in the summer. But in any case in the winter they will hibernate under stones, not in the mud. You might save some of the sludge and put it back afterwards to start things off in the fresh water. Frogs can hibernate in the mud though - you didn't say whether you have frogs.
16 Aug, 2020
if it is leaking I 'd go for doing it sooner rather than later .
sludge removed will have allsorts in it but it will be difficult to rescue most of it. most amphibians will be in the garden rather than in the pond now.
16 Aug, 2020
Did you ever pan for gold? That's what you'll have to do. 1 pan at a time.
16 Aug, 2020