A group of aquarium-bred White’s Seahorses has been released into Sydney Harbour as part of a conservation project aimed at helping to recover local population numbers of this iconic endangered species.
The White’s Seahorses (sometimes called Sydney Seahorses) were part of a recovery project led by SEA LIFE Sydney Aquarium in collaboration with the NSW Department of Primary Industries (DPI) Fisheries and the University of Technology Sydney (UTS).
The project aims to breed, raise and release the White’s Seahorses, and monitor their success in helping reverse the decline, with four key stages now complete:
- Collect. Planning for this project started in August 2019 and kicked off in October 2019 with SEA LIFE Sydney Aquarium team, assisted by experts from DPI Fisheries and UTS collected breeding pairs from Sydney Harbour, including some pregnant males.
- Breed. The seahorses were placed into a custom-built seahorse breeding facility at the Aquarium, and dozens of White’s Seahorses were successfully bred on site and on display to visitors.
- Prepare hotels. In March 2020, nine Seahorse Hotels were placed underwater in Clifton Gardens, Mosman in preparation to become homes for the juvenile seahorses being raised at the aquarium.
- Tag and release. The final stage involved the juveniles being carefully tagged for future monitoring before being released into their Seahorse Hotels in Clifton Gardens this week. The seahorses were injected just under their skin with a coloured elastomer fish tag in a unique pattern, allowing them to be individually identified.
The decline in the White’s Seahorse is largely due to habitat loss and degradation, with much of their natural seagrass, sponge and soft coral habitats disappearing meaning that providing new artificial habitats was a key element in the recovery program. The breeding, release and follow-up monitoring of these seahorses will help shape and expand the long-term conservation of this species.
SEALIFE aquarist and seahorse expert Robbie McCracken, who has led the project over the past 10 months, is thrilled with the project’s success thus far.
“It’s been amazing to see visitors to the aquarium witness first-hand how incredible these creatures are. Since our collection in October 2019 we have successfully bred dozens of White’s Seahorses and to see these healthy, strong juveniles be released into the wild is a significant milestone.”
“While all of the other stages have been important, today was a highlight as we watched our seahorses settle into their new homes.”
Overseeing the release, Dr David Harasti, DPI Senior Marne Scientist, Dr David Harasti who has over 10 years’ experience working with seahorses. The DPI will be conducting regular diving surveys to monitor their growth, survival and breeding in the wild.
“This monitoring program is critical in assessing how the Seahorse Hotels, as a conservation tool, helps the species to recover”.
To help support long-term research of the seahorses, masters research student Brooke (Bee) Kyle will be tracking the success of the new releases and their Seahorse Hotels, supervised by Dr. David Booth, Professor of Marine Ecology at UTS.
Inspired by crab traps, Seahorse Hotels were trialled in Port Stephens in 2018 and 2019 and were found to be very successful in attracting seahorses which led to mating and breeding.
The Seahorse Hotels start as artificial habitats that grow into natural habitats once they are placed in the marine environment. Over time they are grown over by encrusting corals, sponges, algae that colonise these structures, providing protection from predators and a ready supply of food. The ‘Hotels’ are designed to be completely biodegradable, so the artificial structures will slowly collapse over time under the weight of the marine growth leaving a new natural habitat behind.
SEA LIFE Trust’s ‘Ocean Youth’ helped with the Seahorse Hotel construction, along with Seadragon Diving Co. and Sydney-based Indigenous Sea Rangers with support from DPI’s Marine Estate Management Strategy (MEMS).
The Sydney Seahorse (White’s Seahorse)
The species was named after John White, Surgeon General to the First Fleet and is endemic to the east coast of Australia. White’s Seahorses can be found in a variety of colours and they can change their colour to match what they are living on.
Following a dramatic decline in numbers over the past decade, White’s Seahorse (Sydney Seahorse) has recently been listed as an ‘Endangered’ species. It is now Australia’s only threatened seahorse species and the second Endangered seahorse species worldwide.
For more information on the Seahorse Project or to see the seahorses that are currently on display, visit SEA LIFE Sydney Aquarium once the attraction re-opens.