Too many of these poor helpless (unless you count their giant claws) crabs are being hunted for their delicious meat. The hunter appears to be a Scourge orc by the looks of the large footprints all over the beach. I can use this conch to take the form of a crab and use the crab's senses to detect where the crabber is hiding. And when found, he'll be witness to the full destructive power of my pinchers!
Go to the island in the middle of Siren's Cove and find an empty crab shell ( 176, -42, 400 ) Copy/waypoint 175.53, -42.42, 399.75. Fight off the flock of hungry seagulls.
Check Deadwood Refuge for the crabber. Find an empty crab shell ( -107, -31, 185 ) Copy/waypoint -107.34, -30.84, 184.70. Fight off the flock of hungry seagulls.
Check Timberlands for the crabber. Find an empty crab shell ( -447, -37, -39 ) Copy/waypoint -446.60, -37.03, -39.09. Fight off the flock of hungry seagulls.
Check Hounds' Gorge for the crabber. Find an empty crab shell ( -547, -28, -182 ) Copy/waypoint -547.27, -27.97, -181.91. Fight off the flock of hungry seagulls.
Check Scourge Valley for the crabber. Find an empty crab shell ( -13, -5, -321 ) Copy/waypoint -13, -5, -321. Fight off the flock of hungry seagulls.
Go atop the towering rock ( -31, 71, -374 ) Copy/waypoint -31, 71, -374 and kill the crabber.
When the crabbers spawn they may use knock-back on you. Do not let them push you off.
If you die, the crabbers despawn and you fail, so feather fall may be useful.