young fish dying in pond

Question
my pond has been established for about 6 yrs, i have 5 large goldfish which have bred twice,last year and the year before, i am now finding that last years young are all dying i have over the last few days lost about 12 young, the older fish seem ok, for now, can u give me advice on what it could be, i really dont want to lose anymore, thankyou joan

Answer
Hi Joan,
Thanx for your questions.  Can you tell me where you live?  What kind of winter have you had?  Have you examined the carcasses of the fish to see if there was any disease or injury.  Your pond may be over crowded too.  Is there ice on top of it?  Please answer these questions for me.
thx,
Tom