On Jun 26, 6:58�am, Christine_B Christine_B.
wrote:
I have recently had a company edge the pond with stone.

In carrying out this process, five tench I had in the pond have died.
After the work was carried out they were initially distressed, and
sadly died towards the end of the day.

I can only surmise that the cement from the work has entered the pond
in sufficient quantity to cause polution? �Is this a likely cause?
There is also other wildlife living in the pond, newts frogs etc, and I
am worried as to the effect the cement has on them. �

What is the best way to go about cleaning up the pond so as not to
cause any further harm to the remaining wildlife?

Why did they use cement (you probably mean concrete), portland cement
and pond life don't mix. You hired a company that does masonary but
they obviously know nothing about ponds, nor do you. That "cement"
will leach into the pond for 20-30 years, maybe longer. Your only
remedy is to carefully and completely remove that stone and "cement"
coping. Properly set stonework is self-interlocking and needs no
adhesive... why pay for natural stone if it ends up looking ridiculous
when held together with an unnatural substance. You need to decide if
you want a pond or a pool.