Question
To set the context: I live in England and about six years ago we dug a pond in the garden (at max it is 12 foot in diameter, and 5 foot deep in the very centre, but there is a shallow shelf all the way round). We introduced some oxygenating weed, a couple of lilies, and a few small fish (from memory there were 4 goldfish, 4 golden orfes, 2 ghost koi and 3 shubunkins). When I built it, I bought a small-middling pump and filter barrel to run a stream/waterfall, but someone dug through the pipe so it hasn't been run for years. Similarly, I haven't fed the fish for years as the pond seemed to have reached some kind of natural balance. In the early stages we had some green algae and/or blanket weed, which I would pull out and I tried a variety of chemical treatments for this, but more recently it has been much less of an issue.

Nonetheless, despite my neglect the pond seems to have thrived, in that we have frogs, toads, 3 varieties of newts, a variety of insects and the fish have bred with loads of little fry appearing.

The pond has changed over time and we have tried to intervene when ever it is necessary. About 18 months ago the lilies grew to fill the entire space and make the whole pond almost solid, so we had to cut them up with a machete and pull them out (we left them on the edge of the pond for a few days to let any creatures make their way back in before disposing of them#. However it is apparent there is a lot of sediment in the base of the pond. Also a heron came and fished out the brightest/largest fish and punctured the pond, so we had to locate and repair the hole. We think the same has happened again more recently as the water level has fallen. Since then the oxygenating plants have expanded to fill all available space, so I worried the fish were being crowded out of a shrinking water space.

We are now building a formal raised pond instead #as this will be safer now we have had children# and want to transfer the fish and wildlife to it. It will be around 1 metre deep and 2 metres by 4 metres in size. I have made a temporary container filled with about a cubic metre of water #treated to remove chlorine etc) into which I am trying to move all the fish as I empty the pond. However I am less confident about moving the plants/amphibians. I also want to ensure that we get the balance right between the different plants and creatures in the new pond.

So, I have a number of questions about this.

1) Do I try to catch the frogs/toads/newts and put them in my temporary pond? Will they be okay if they can't get out for a month or two? Or are they better being left in the garden or released in a local wild area? I'm worried as we have to fill in and pave over the old pond to build our new garage. Similarly, do I make an effort to move the bugs and underwater creatures, or will they survive if I tip the sediment onto the garden?

2) if we build a raised pond, this would normally have vertical edges - is this suitable for the amphibians? Do I move them in when we empty the old pond or hope they arrive themselves? Do they need a means to enter/exit the pond? Will they only like a 'natural' pond that is shelved and has sediment and plants or will they be okay with a clean/formal pond?

3) I am thinking to invest in a more substantial pump and filter, and run a cascade into the pond. I assume this is good for the fish, but how will this affect the plants/amphibians?

4) I like waterlilies, but the pond will look "cleaner" if we don't put in loads of oxygenating plants and keep the filter system on more of the time. Do we need plants? If so, how can we get the quantity right so they don't overgrow everything? Can we have plants and avoid sediment? Should I try to move some of the oxygenating weed from the current pond to the new one?

5) The fish I have caught so far, with the exception of one goldfish, don't look like the fish I put in. They are blackish on top and pale gold underneath, ranging from 3 to 6 inches in length. They are slimmer than the goldfish but taller. I've not seen any fish which are long and thin like the orfes were when I put them in. Could they have grown into this different shape/colour, or could the different species interbreed? I have to assume that sadly the koi and shubunkins were victim to the heron :( although they may still be hiding as there is still quite a lot of pond to clear.

6) I'm hoping that this time of year is good to move a pond, whilst things are less active and not breeding, but is there any advice on how to cause the least stress to the fish/animals/bugs? My plan is to gradually scoop out the weed onto one side of the pond (onto the now exposed shelf) and the sediment onto the other, allowing me to move some of the water and gradually capture everything alive to move to my temporary pond. Is this methodology rational or is there a better way to do it? I want to keep living things but leave the sediment behind.

Many thanks in advance for advice, and apologies for the long multi-part question!
Miriam

Answer
1)  Drain the pond to about a 1/3 of a meter.  This will make it much easier to make sure you removed all of the fish.  It may also prompt the amphibians to leave the area.  The fish are the only ones dependent on the water you have placed there.  The rest will be able to find their way to another satisfactory location.  The frogs, etc. may become trapped if you fill it in, so maybe try to stir up the mud a bit because there may actually be a few fish in the mud too.

2)  A good sized piece of driftwood resting on the edge would allow smaller creatures to get themselves back out of the pond.  They probably won't have a problem getting into the pond.  They would be more attracted to a dirty pond because of the cover it provides, but this is YOUR pond.  You should design it how you want it and if they choose to live there, so be it.

3)  A cascade is relatively detrimental to some plants as it causes CO2 to leave the pond more readily.  However, at the proper stocking ratio of fish:plants, the fish provide enough CO2.  Plus, the fish need the oxygen levels promoted my having a cascade.  I would recommend running the pump 24/7 because the filter that it will run through accounts for most of the living space of nitrosomonas and nitrobacter, which are responsible for maintaining good water quality in a living pond.  The amphibians won't care too much either way, but they will be using the same Oxygen that the fish will be trying to use.  
p.s.  you want a pump that can circulate the pond 2x in an hour, already factoring for loss of flow due to head pressure.

4)  You pretty much always need plants.  Use baked clay chips instead of potting soil.  Then put a layer of gravel on top of the chips in each aquatic planting basket.  If your oxygenating weed is either anacharis or horn-wort, you should move some of it, although horn-wort can be a little bit messy.  You should aim for about 1/2 of the pond's surface to be shaded by plants.

5)  It really is hard to say what those fish could be or where they came from.  Try looking at a few pictures of pond fish online and see if you can identify them yourself.  (Sorry I couldn't be of more help on this question)

6)  I would do it all in one day because you will be stirring up a lot of sediment in this process.  That floating particulate can damage fishes' gills.  Also, start by draining the water from the top until it is shallow enough to see all of the fish.  They won't want to be caught and will make it as difficult as possible for you.  The last time I revamped a decrepit pond, it took 8 1/2 hours; 3 hours to drain and remove the critters, 3 hours to clean, and 2 1/2 hours to fill it back up and reintroduce the fish.  So, get the fish and then you can take a well-deserved break.

I hope this puts your mind at ease.  Feel free to ask me any more questions you have during this process and once your new pond is under way.

Jon