Leaches

I've sorted out the overstocking of the pond to give Jaws more room, but
in the process I've found that the pond is overrun with leaches.

I've not introduced any new fish or plants for years. Those fish that
were in the pond have bred themselves.

Can leaches come in on frogs etc?

How do I get rid of them short of draining the pond and filling it in?
I cna't even lift Jaws out, let alone keep him somewhere else whilst I
clean the pond out.

It's begining to look like "goodbye pond". I'm getting too long inthe
tooth to be scrambling about on my hand and knees. The athritis tends
to restrict what I can do these days.

Is there any chemical cure?


--
Snoddywig