Off the drop off past the bayside flats on Cape Cod are really big sea clams weighing over a pound each that lie slightly open waiting for something to clamp on. If you are working too close to the bottom you could be 'clamped'. These are so heavy that in a rip current they feel like a fish shaking it's head and folks have made the "fish on" call to a sea clam in the current more than once while I was with them. :hehe: This is also true of the moon snails which have a large 'foot' up to 6-8" in diameter that contracts when nicked by a fly. Talk about impossible to remove! The most ridiculous thing I have hooked on a fly is a full grown grey seal - it swam up, inspected my sand eel fly and ate it! After a long drag burning run I clamped down and popped the leader. You should've seen the dumb dog look it gave me when it popped it's head up to see what the heck happened! No fly in it's lip by then, it was barbless / single hook and probably plucked it off with it's fin easily. It's brothers who stuck their heads into lobster traps aren't so lucky - there are many seals wearing bright nylon death necklaces along the coast. Maybe it's time to think about biodegradable netting or a center bar in the opening of the trap, etc.
Anyway, I digress... no clam has the presence of a GEODUCK!!!
Geoduck Book / Image from Amazon