Pond Boss Forums INTRO Questions & Observations Help with Yellow Perch - small, small, small

Some fish species are more vulnerable to the black spot disease that others. Typically the fish gets infected with black spot at a young age because the fish eats the tiny infecting organism "thinking" it is a zooplankter. Fish that are frequently feeding in the bottom areas near the snails I think enhances their chance of getting infected. Removing the infected fish probably has little long term impact on eliminating the disease in a moderately infected pond.

You maybe do not have too many snails but too many fish eating birds visiting the pond?. It is possible that the fish were infected when originally stocked.

A fish hatchery owner once told me that the black spot disease will eventually work itself out of fish in time; but I am not sure of that time frame. The encysted organism could complete or advance its life cycle and emerge from the fish. I am not sure about this. Maybe an experienced hatchery person with experience with this topic can provide an opinion.