Goldfish in Alexandra Pond

I saw some goldfish in Alexandra Pond today, just where there's a shallow bit formed by the high water level, opposite the little row of shops. My eye was caught by a red coloured fish about 4-5 inches long, basking in the sunshine. Looking further I could see 9 or ten others, brown coloured, and some much bigger. That's the first time I've noticed fish in the lake but knew there must be some in there due to the fishing birds such as heron and cormorants which are  attracted to visit sometimes.