This is the second shark I've seen in about 500 dives… the first one was a Nurse Shark in panama and this one, I'm not sure the name but sadly the only thing remaining was the head, spine and tale...
My guess is fishermen… We fear sharks but there are not so many left… for every human killed in a shark attack there are millions of sharks killed by humans… even worst most of them are killed just for their fins and the rest is thrown back to the sea...
Original Photo