University of Technology Sydney: New ‘hotels’ a suite haven for baby seahorses

Eighteen underwater hotels have been installed in Sydney Harbour to provide homes for one of Sydney’s most precious and endangered residents, the White’s seahorse.

World Oceans Day is a day to inspire action and protect the ocean. To mark the occasion, 18 new seahorse hotels are now underwater in Sydney Harbour, ready to provide vital housing for the next colony of baby endangered White’s seahorses.

The hotels – nine each at Delwood beach and Little Manly beach – will welcome the next generation of Hippocampus whitei babies to be released from SEA LIFE Sydney Aquarium in September, in time for National Threatened Species Day.

SEA LIFE Sydney Aquarium curator Laura Simmons says the multi-year project, now in its second year, has maintained strong momentum through vital stages on the way to de-listing the currently endangered White’s seahorse.

A newly installed seahorse hotel on the harbour floor
The seahorse hotels grow into natural habitats after they are placed in the marine environment.

Simmons says the deployment of the new hotels on the eve of World Oceans Day is another major milestone for the seahorse team.

“We tripled the number of seahorse hotels in Sydney Harbour. Successful seahorse hotel deployment is critical as the Posidonia seagrass and the cauliflower soft coral that seahorses call home are also endangered. The seahorse hotels provide the perfect haven for these seahorses and their native habitats to flourish,” she says.

The hotels start as artificial habitats that grow into natural habitats once they are placed in the marine environment. Over time, the corals, sponges, algae and encrusting animals that colonise these structures provide protection from predators and a ready supply of food, making them the perfect home for seahorses.

It is essential we maintain and protect the marine habitats they rely on. If we lose the habitats, we lose the seahorses.
Dr David Harasti

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.

Dr David Harasti, senior marine scientist with NSW DPI Fisheries and a UTS Alumni, has more than a decade of experience working with seahorses.

“To ensure the survival of the White’s seahorse in the wild, it is essential that we maintain and protect the marine habitats that they rely on. If we lose the habitats, then we lose the seahorses,” Dr Harasti says.

UTS has developed a strong collaboration in research and research training to deliver great conservation outcomes for the endangered White’s seahorse.
Professor David Booth

UTS Professor of Marine Ecology David Booth has a long involvement with the White’s seahorse breeding and recovery project.

“UTS has developed a strong collaboration in research and research training with our partners to deliver great conservation outcomes for the endangered White’s seahorse,” Professor Booth says.

“Our postgrad and undergrad research interns have helped to rear baby seahorses and Mitchell Brennan, SEA LIFE Sydney Aquarium aquarist and seahorse expert, is conducting his master’s research as part of the program.”

Other project collaborators are Ocean Youth, the Gamay Rangers and the Sydney Institute of Marine Science. Taylors Wines, whose labels feature seahorses, provide support.

TIMELINE TO SAVE THE WHITE’S SEAHORSE
Collect In October 2019, SEA LIFE Sydney Aquarium team worked closely with experts from DPI Fisheries and UTS to collect breeding pairs from Sydney Harbour, including some pregnant males.

Breed The seahorses were placed in a custom-built seahorse breeding facility at SEA LIFE Sydney Aquarium, where dozens of White’s seahorses were successfully bred and put on display for visitors.

Prepare hotels In March 2020, nine Seahorse Hotels were placed underwater in Clifton Gardens, Mosman to provide new homes for the juvenile seahorses being raised at the aquarium.

A baby seahorse after tagging and release, swimming in a hotel
A baby White’s seahorse swims at a hotel after it has been tagged and released into Sydney Harbour.

Tag and release In May 2020, juvenile White’s seahorses were tagged for monitoring. The seahorses were injected just under their skin with coloured elastomer fish tags in a unique pattern, allowing them to be individually identified. The tagged seahorses were released into their Sydney Harbour Seahorse Hotels.

Additional hotel drop In June 2021, the team tripled the number of Seahorse Hotels in Sydney Harbour, with nine Seahorse Hotels deployed at Delwood Beach and nine in Little Manly.

Baby seahorse release #2 In September 2021, dozens more baby seahorses will be tagged and released into the new Seahorse Hotel sites.

ABOUT 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 seahorse is also known as the Sydney seahorse. It can be found in a variety of colours and can change colour according to its surroundings.

After a dramatic decline in numbers over the past decade, White’s seahorse has been listed as an endangered species in NSW. It is now Australia’s only threatened seahorse species and the second endangered seahorse species worldwide.