This winter a small group of Merganser Ducks has taken up residence on my 8 acre pond. I know these to be fish eating ducks.

I'm concerned about what affect they may have on my Bass, Bream and Catfish. My fish population is a mature one with a good balance.

I've read the Merganser can be beneficial in thinning smaller fish, allowing larger fish to flourish.

My concern is a drop in overall fish population.

Any advice? Let them stay? Move them out?