Hello,
The Chesapeake crabs must see clearly through a pot. Let it get bent and battered or heavily fouled with marine growth and they will studiously avoid it.
William Warner, Beautiful Swimmers: Waterman, Crabs and the Chesapeake Bay
Does "fouled" here means obstructed/clogged? Or does it mean made dirty?
Covered with barnacles and marine animal secretions or snared and tangled in a way to make it unusable. com/dictionary/english/foul
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Covered with barnacles and marine animal secretions or snared and tangled in a way to make it unusable.
See entries #5 and #7
https://www.collinsdictionary.com/dictionary/english/foul