Just build a little fence and put some sticks on the cover
try going here http://www.bing.com/images/search?q=cutthroat+trout%5C&form=QBIR#
not if you're in Idaho (i don't think they're poisonous)
I believe a Bull Trout eats a cutthroat trout.I hope this is what you were looking for
They cant protect themselves because humans are smarter and we can catch and eat them..