Hope for weedy sea dragon future following rare breeding success in captivity

CHRIS Carey describes it as the “holy grail” of breeding Australian sea creatures in captivity – achieving the successful egg transfer for weedy sea dragons.

The feat is so rare that it has only been accomplished a handful of times anywhere in the world.

And Seahorse World at Beauty Point in Tasmania could soon join their ranks after a male weedy sea dragon was seen carrying the eggs under his tail, completing the successful courtship process with a female.

Now they are just waiting for them to hatch.

Mr Carey, the aquarium’s manager, said it was a delicate process that required close attention, but was also shrouded in mystery. There is still little understanding of exactly how the breeding process takes place.

“You need a whole lot of luck on your side,” he said.

“You have to provide the perfect environment for the sea dragons to do their thing that they naturally do – allow for the right space for them to perform their courtship dance.

“Now we just play the waiting game, dote on him a little bit, give him a lot of food, make sure he’s well nourished and provide the nutrients for his eggs and babies to grow.”

The sea dragon could carry the eggs for between eight and 12 weeks before they hatch, giving the public ample time to observe the rare occurrence.

The successful mating pair were among the hatchlings of sea dragons captured while carrying eggs in the wild, and have spent their lives in captivity.

Sea dragons that have been hatched in captivity do not require live feed, and so are easier to raise. They are also the only ones that will breed in captivity, provided the waters match their natural environment.

Mr Carey said it was an exciting time.

“Seahorse World has always been trying to push the captive breeding conservation message. We teach our visitors about these amazing creatures, why they’re so important, and why we need to look after them,” he said.

There is much concern for the future of the Weedy Seadragon and others in their family. They are threatened by habitat destruction.

In 2016 the Leader reported concerns over impacts on weedy sea dragon numbers in Botany Bay following dredging in the bay to lay a 2.1 kilometre long high voltage submarine cable.

Scuba diver instructor and marine biology teacher, Mike Scotland at the time that dredging  carried out for the cables, the expansion of Port Botany and the Kurnell desalination plant had resulted in major detrimental impacts on marine life in particular the weedy seadragon population.

“The muddy water created by construction causes the entire food web to die as sunlight cannot penetrate the dirty water,” Mr Scotland said at the time.

“The entire food web suffers and begins to die off. Siltation also fouls up marine fauna and flora, killing seaweeds, sponges and corals.”

A University of NSW study in 2006, before much of the dredging, had found 45 and 49 weedy sea dragons during dives at two locations around Kurnell.

“The sea dragons disappeared completely from Bare Island and Sutherland Point when the dredging started, but are slowly recovering,” Mr Scotland said.

Researcher John Turnbull told the ABC in 2017 that the kelp that the sea dragons depended on appeared to be thinning out in Botany Bay at Kurnell 

"The numbers here are down. This is the best site in Sydney, so you can still see them here reliably," he said.