The ugly plight of a cute sea critter

Among the many creatures in Wellington's Mahanga Bay cold-water aquaculture tanks, the title of quirkiest aquatic critters goes to the large-bellied seahorses.

They look affable and when you peer into their tank they rush upwards as if to say gidday.

They resemble a cross between a fish, a horse and a helicopter - whirring fins propel them to the surface - and they certainly have charm.

Several centimetres long, they get their name from their distinctive paunches. Males have the greater girth and as they carry the young in pouches they are positively pot-bellied.

Mahanga's large-bellied seahorses originate in Wellington Harbour and have been breeding in the lab for five generations.

Dr Rob Murdoch, research director of the National Institute of Water and Atmospheric Research (Niwa), delights in pointing out a pair of large-bellies romping around.

"You can tell the male with his big belly and as it appears swollen they seem to be getting ready to mate," he says as the large-belly unashamedly pounces on his mate, his paunch butting her into the tank wall.

"They're real characters and charm everyone who sees them."

But charm is no help to seahorse survival and, with rampant exploitation for oriental medicine and the international aquarium trade, they are fast vanishing from the oceans.

Globally it is estimated that 40 million seahorses are dried and sold for medicine each year. A further million enter the aquarium trade.

And that is where Mahanga Bay aims to help, with marine biologist Chris Woods. He is a recognised seahorse specialist and champion of their cause.

Woods is so devoted to his charges that he says he has become personally attached.

"You're not supposed to but they're so interesting to work with. I even used to name them at first but now there are too many of them."

Woods' devotion earns a ribbing from his mates, especially paua specialist Graeme Moss.

"He gets all upset and angry if they get hurt or die, especially when he gives them away. They're his best mates."

Jokes aside, Murdoch says Woods' research leads the field. "Chris is at the forefront of research on farming seahorses."

Mahanga Bay boss Phil Heath adds: "Seahorses are fed with great difficulty because when they're young they have to feed on live organisms, which is very hard and expensive to manage on a commercial scale.

"It's like with babies who are difficult to feed - once they get older you can wean them on to hamburgers.

"And Chris has developed some very effective 'hamburgers' - dry pellet feed which will be a great aid to seahorse farming."

As for the commercial future of large-bellies and other seahorses, Murdoch says the potential for success is there. "The seahorse industry won't ever be massive but the value will be significant despite the small volumes."

There is a semi-commercial operation in Hawkes Bay farming seahorses but Murdoch doubts it is making money.

- NZPA

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