Oxygen-deprived high organic pond?

[OckViewer]

Following on from my previous post, I've been doing research (wikipedia) and have found the 'Rat Tailed Maggots' live in Oxygen-deprived water with high organic content?

This is despite having pond snails to control the algae and curly pond weed for oxygenation.

Does this mean our pond is in poor health? If so, is there anything we can do about it? Or will it sort itself out.
It is a small wildlife pond and does not contain fish.

Thanks

Richard

[AshLee]

I don't get Rat-tailed maggots in my pond (I'm kind of envious of you - they look interesting) which is very clear and packed full of plants - floating, marginal, oxygenating.

Make sure that your pond doesn't have rotting vegetation in the bottom, like dead leaves (I remove any from my pond every spring and sometimes in the autumn).

Why not post a picture for further advice?