Last month a belted kingfisher visited the pond several times a day for at least two weeks. It managed to take out the goldfish at will. Since we have a very large population of fish, I wasn't alarmed as I watched it skillfully pick fish from the water. Eventually the fish totally disappeared with no sightings of the larger or even the very small fish. They seemed to sense the attacks and have been hiding deep in the pond for some time. The kingfisher lost interest in its fishing expedition several weeks ago, but the fish have yet to surface in numbers. In just the past couple days they can be seen deep in the water from time-to-time, but there is no way to get a count or idea of how many survived.I suppose the breeding season is under way so there should be plenty of replacements.Nature works that way.The pond was designed with anticipation of predation.There is a deep section and areas of heavy vegetation with underwater rock crevices and other hiding areas for fish, frogs, tadpoles, etc to escape predation.