The British conservationist fighting to save the seahorses of Cambodia from extinction

A seven-inch creature with a head resembling a horse and a monkey-like tail glides gracefully out of a dark coral crevice off the Cambodian coast. Master of camouflage, unrivalled as a hunter and a much-loved figure of ancient myths and legends, the seahorse may be spiralling toward annihilation after surviving beneath the waves for some 40 million years.

Taking photographs and detailed notes, two divers swim through turbid water to spot the male in the crevice and a nearby female, both hanging on in a once-pristine habitat turned to withered coral beds and ragged remnants of seagrass meadows.

The tropical seas around this jungled island depict, in microcosm, both the seahorse’s threatened state – tens of millions are harvested globally each year – and possible ways to save the iconic species from extinction.

“The seahorse faces an enormous variety of threats,” said Paul Ferber, a British conservationist who has lived on Ach Seh Island for three years, studying the genus Hippocampus and trying to protect its ravaged environment against an armada of illegal trawlers, crab traps and divers in sleek longboats specifically targeting seahorses and related species.

Peering into the darkness one night, Ferber hears the tell-tale chugging of his No 1 enemy: trawlers from neighbouring Vietnam dragging miles-long nets with mesh so fine that even creatures smaller than seahorses can’t escape.

“Big, nasty Vietnamese [boats]. It’s either a seine trawler or a pair of them,” he said of vessels that leave behind a lifeless ocean. If equipped with electrified nets, they can even stun and suck in living things burrowed in sea beds.