Hi there Im new here and looking for some input.

I have owned fish for a few years (cold water in a tank) and have recently had the garden landscaped with decking and a sunken pond. We also had a big Pergola built over the top for cover. After cycling the pond - I have now been able to stock my pond. The pond's water level is in line with the decking boards. I have my Koi (2 small metallic) some gold fish, a small albino sturgeon, a small sterlet and as of last weekend, Spike - my Stellatis Sturgeon - about 14". Spike I waited for - until everything was totally pucker with the pond.

This morning I came down at 6:30 to a nightmare :-( Spike was lying in the middle of the grassed lawn - some way from the decking/pond. He was still breathing and no "visible" marks. To cut a long story short - he didnt make it although I tried my best - floating him around the pond, - he responded initially but I had no idea how long he had been out of the water - or why !

Tonight I have put a "crass" net over the entire pond in case we have any more predators. Now I am trying to work out what the options are for what happened. I d appreciate any thoughts.

a) |He jumped out of the pond - doubtful but I suppose possible

b) A Heron - although I think it would have taken off with the fish, it would have had marks ???? or there would have been more fatalities??

c) CAT ! My partner thinks this but I am not sure. He would certainly be easy prey since Sturgeon do come around the surface in darkness and he would have been easy to swoop !

Any ideas guys ? And also any advice on "custom made" nets/fitments and where I can source one.

Many thanks

Simon