What effect do goldfish have on the native wildlife in a pond?

Question

There's a pond I am studying and its very rich in wildlife, however goldfish were introduced and they are described as a pest, because they eat things, I think. What do they eat in the pond? Why are they harmful?

Answer 1

They eat all the native fish in a pond.

Answer 2

goldfish aren't compatible with all fish and can be aggressive towards smaller fish.  They also eat everything. so they can be harm full.  they are also really dirty fish.

Answer 3

Well it maywell be true but I can tell that I had a wildlife pond and in that pond were both goldfish and Koi Carp. My wildlife pond survived and so did the fry that these fish spawned. Small insects will hide under rocks and in weed. There are other predator like frogs who feast on pond creatures and insects. So I would say that unless a pond was inudated with goldfish then the balance will be fine.

Answer 4

They eat basically anything and everything. If they eat all the weeds they will starve the water of oxygen because weeds put oxygen into the water.

Answer 5

a goldfish is a fancy variety of a common carp, carp are mostly bottom feeders and will forage in the silt for any worms,larva ,insects and snails in doing so up rooting plants and making the water cloudy. there not realy a pest unless they've been introduced into a warmer enviroment and multiplied to the extent that they've driven out the native species( like in australia).