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?

Thank you in advance.