I am seeking some advice. We have approximately 200,000 gallon spring-fed trout pond. Over the years, we have developed an anchor worm issue which hasn't resolved with the pond freezing. Most likely, because the females continue to stay warm while attached to the trout.

We have wildlife that relies on the pond as a water source, so I am hesitant to drop chemical, which for this size is around $13,000 for 7 days with no guarantee. We are also hoping not to drain the pond as we can't tax our well system and delivery to refill is very expensive.

Does anyone have any ideas on how to approach this problem so that we can eradicate this parasite from our pond?