The Marshall Islands government has created the world’s largest shark sanctuary, covering nearly two million sq km (750,000 sq miles) of ocean. The Pacific republic will ban trade in shark products and commercial shark fishing throughout its waters. Tourism, including diving, is a staple of the Marshall Islands archipelago, which is home to just 68,000 people. Sharks and their near relatives such as rays are seriously threatened by issues such as habitat loss and fishing. About a third of ocean-going sharks are on the internationally-recognized Red List of Threatened Species. “In passing...

Swimming with the gentle giants of Tofo. Eyes stinging with the wonder of it, my head breaks the surface and a rippling swell sloshes about my ears. Up here all is hysteria, hyper-adrenalized euphoria: 16 goggle-eyed tourists treading water, yelling astonishment through surf and snorkels. Bubble, splash, gurgle . . . “ . . . mazing’’ . . . “ . . . did you see?’’ It’s an understandable reaction when you have just been for a paddle alongside a shark the length of a bus. It didn’t require much courage. No one has been left with a ragged stump where an arm once was; no one’s innards...

Some shark species make “mental maps” of their home ranges, allowing them to pin-point destinations up to 50km (30 miles) away, research suggests. US-based scientists analyzed data from tiger sharks tagged with acoustic transmitters, and found that they took directed paths from place to place. Other species such as blacktip reef sharks did not show this behavior. Writing in the Journal of Animal Ecology, researchers suggest this shows a capacity to store maps of key sites. In addition, it is further evidence that the great fish can navigate, possibly using the Earth’s magnetic...