A beautiful 500 piece puzzle featuring a picture of two graceful pantropical spotted dolphins they are also known as marine dolphins and use echolocation to navigate and hunt bouncing high pitched sounds off objects and listening for the echoes one of the greatest threats to dolphins is accidental entanglement in fishing gear known as bycatch this causes the deaths of more than 300 000 cetaceans dolphins porpoises and whales every year the world wildlife fund wwf promotes ways to