Were these Medical issues? Did I understand the problems correctly......some of you had a fish, a snake, or some eel grass where the sun don't shine?
We once had very small sea shells lodged in an elbow of the raw water intake line. (Yes, I know that is no place for extra connections like an elbow.) Whether they were living there or whether empty shells had been sucked in from shallow water I don't know. The shells were crunched to smithereens by the time I cleared the elbow with an awl.