Little Fish Gallop Back Into The Wild

November 14, 2007

Release from: Yuko Narushima
Sydney Morning Herald (Australia)

FLOATING in a tank the 30 seahorses that had been bred in captivity looked like a tangle of black seaweed.

It was when the finger-long creatures were scooped out one by one and released into Sydney Harbour that their spiny S-shaped forms became distinguishable.

The release of the herd into net-protected waters at Manly Cove was a first for Australian marine scientists who are researching ways to boost seahorse numbers in areas where their stocks have been depleted.

David Harasti, the NSW Department of Primary Industries marine scientist behind the project, said habitat was crucial to their survival.

"If they've got a habitat where a male and female can curl their tails around, they'll hang on tight near each other and come together every morning in a courtship dance," he said. "The male and female come together and twirl their tails. That's how they mate."

Curling and twirling seahorses are prolific breeders in the wild but are under threat nearer humans because seabeds they need to survive are being destroyed. The sea grasses and algal beds the fish cling to are being destroyed by boat anchors and extensive fishing.

"It's their actual habitat that's at threat," said Claudette Rechtovik, program co-ordinator for the Sydney Aquarium Conservation Fund, which gave $5000 to researchers. "To breed is one thing but to have the babies survive is another. In the wild, they have quite a high mortality rate."

Seahorses, which are protected in NSW, are also poached for the black market where they can be sold as pets for $120, used in medicines or bottled in "seahorse vinegar", Ms Rechtovik said. "They are really vulnerable. They can't swim very quickly," she said.

Sydney Harbour is home to about half of the 40 species known to exist. As many as 400 seahorses live in the netted area next to the ferry terminal at Manly Cove and with summer approaching, their preferred breeding season, that number is set to increase.

"Seahorses are the most unique animal in the world. The male seahorse gives birth," Mr Harasti said.

"The female deposits her eggs into his pouch and he'll give birth four times a year."

At six months of age, the released seahorses are sexually mature. They are tagged and will be monitored by divers weekly for the next two years.

"Grab your snorkel and take a look," Mr Rechtovik said. "A lot of people are really surprised that we've got things like seahorses in Sydney Harbour. The harbour is rich with life."