Seahorses of Sydney Harbour

Gently does it: seahorses take a bath in their new home
Kelsey Munro Sydney Morning Herald 4 Dec 10;

HOW things have changed. Veteran scuba diver Dave Thomas remembers when Sydney Harbour was toxic from factory waste pumped into the Parramatta River.

These days, environmental attitudes have changed so much that he and his team were asked to move a delicate colony of seahorses out of harm's way while Woollahra Council rebuilt the century-old Watson's Bay baths this year.

The baths, which will reopen on Friday, have long provided a habitat for a small colony of White's seahorses.
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''Their natural home is seagrass, not swimming pool nets, but they prefer them because it gets them off the ground and away from predators,'' Mr Thomas said. ''And they can't chase things down, so they rely on food coming to them. They love hanging in the nets while things go past.''

Mr Thomas and divers from his volunteer group, Eco Divers, made about six dives to move the seahorses from the baths, working just ahead of the crews who were demolishing the old wharf.

''We hand-picked the seahorses off the nets or seaweed,'' Mr Thomas said. ''They hold on by their tail, so you have to hold their shoulders, you have to be very gentle. After a while they relax and you can move them.

''We carry a little mesh bag - the sort you put in a washing machine for your delicates, that's ideal - and then we just move them out of the area and put them on seagrasses on the same depth contour.''

The mayor of Woollahra, Isabelle Shapiro, said the council consulted with NSW Fisheries on how to minimise environmental disturbances during demolition and construction.

"Council was very careful in ensuring all consideration was taken to protect the marine life when designing the Watsons Bay baths renovations,'' she said.

The divers have previously moved a seahorse colony at Clifton Gardens and other vulnerable species in the harbour. The group is part of a project, with Sydney Aquarium, to release White's seahorses bred in captivity into the harbour to help boost their numbers.

The seahorses, endemic to Sydney and the NSW coast up to Port Stephens, typically grow to an uncurled length of about 20 centimetres and are a protected species.

Mr Thomas said their habitats had been greatly depleted through the loss of harbour seagrasses, but the 2006 ban on commercial trawling had improved matters.

With heavy construction finished, Mr Thomas said the seahorses were beginning to gravitate back to the new nets around the baths, which were designed with them in mind.

The council spent more than $2 million upgrading the baths, which were opened to the public in 1905.

The work includes a new 50-metre lap pool with two sunbathing pontoons, a water ramp for wheelchair users - which the council says is an Australian first - and new shark nets.