WI.IL.Fish4life

So coho, and steelhead, and trout with this giant sharp teeth can't bite through the flourocarbon? I'm something of a greenhorn when it çomes to salmon and trout fishing.... And the guy who taught/got me into salmon/trout fishing on lake Michigan moved away, but I was told to always use a steel leader.... I know that these will spook the fish.... I'm just worried about the fish biting through the line, like a pike and mono.