Fish overpopulation can be caused by several factors. One is simply overstocking your pond in the first place and the second is lack of fishing. Fish overpopulation can be pretty common in a lot of private ponds and lakes. If these bodies of water are hardly ever fished, then over population is almost a guarantee.
It is important to contact your local fish hatchery to get accurate stocking rates for the size of your pond and the species of fish you want to stock with. Overpopulation can be avoided by regularly fishing your pond each year or allowing others access to your property to ensure your population stays in check.
For more information on fish stocking and over population please contact Sanco.