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(ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering...
Hmm, I’m not sure I remember seeing an otter on the surface that that wasn’t preening (a behavioral pattern) or eating. It “might” be arguable if sitting on a float is sheltering or not.
How about a cherry buoy with a suspended bag for lead weights? I don’t recall seeing an otter on one of those — come to think of it, it would be fun to watch them try. Cute little buggers.