Tilapia have no downside in a pond they can not live year round in, unless you consider large quantities of forage, improved water quality, much higher pond biomass capability and excellent algae/vegetation control to be detrimental in your pond.

In a pond that could have very mild winters with water temps only dropping briefly into the mid to upper fifties (<3 days), tilapia could pose major overpopulation problems in the 3rd year of survival. Tilapia will not spawn regardless of water temps without an adequate photo period of 12 hours so there will be no winter reproduction in an outdoor pond. The second year of survival would produce tens of millions of fish and the would consume nearly every available nutrient in that third year before any other species would have a chance of getting it....All fish would eventually stunt and starve creating an eventual DO crash.

In more mild climate areas, stock only Mozambique or Nile tilapia, or any mixed sex hybrid tilapia which all die from 52-58 degrees and become disease vulnerable about 10 degrees cooler just to be safe...My Blue Tilapia are pure strain and are the only tilapia capable of surviving from 42-45 degrees...I will not sell to owners in mild climates wanting to stock ponds.

Tilapia should NEVER be stocked with the hope that they will survive year round in a pond. Consider tilapia as another pond management tool, the same way you use feed or chemicals to help reach management goals.