If someone adds millions of small fish to a lake, how would the number of big fish change

It will throw the food chain/food web off to where the the small fish population will out numbered the big fish population and I know certain animals eat the big fish like bears and if they get out numbered then the bears won't really have anything else to eat and will eat other organisms like berries and other animals. It will completely throw off the food chain. 

Hope this helped :)
Have a great day

Everything that you need in a lab is in your lab