Beneath the Surface: 300 White's seahorses check into underwater Port Stephens hotels in program to save endangered species

White's seahorses bred at Sea Life Sydney Aquarium will be released at sites where artificial habitats, known as seahorse hotels, have been established around Nelson Bay and in Sydney Harbour.

"This is part of the conservation stocking program for the endangered White's seahorse being undertaken by NSW DPI and Sea Life," Dr David Harasti, senior marine scientist with NSW Department of Primary Industries - Fisheries, said.

"As a result of the floods that occurred during 2021 and 2022, the marine life in Port Stephens suffered from the inundation of freshwater with many habitats and species observed to decline in large numbers.

"One of the species that has been observed to experience dramatic declines is the endangered White's seahorse with its occurrence within Port Stephens considered to be rare now, whereas 10 years ago it was very common."

Dr Harasti has been studying the White's seahorse for the past 20 years to learn as much as possible about the biology and ecology of the species to help with its conservation in the wild.

The medium-sized seahorse is endemic to the east coast of Australia and known for once being abundant in the waters of Port Stephens, Sydney Harbour and Port Hacking.

The species is also known as the Sydney Seahorse due the important role it plays in the harbour's ecosystem.

Port Stephens used to be home to the largest White's seahorse population but numbers have severely declined to the point that it was listed as endangered in NSW in 2020.

It is now Australia's only threatened seahorse and the second endangered seahorse species worldwide.

"Port Stephens was considered to be a prime location for the White's seahorse as the Port has a huge diversity of marine habitats, such as sponges, corals and seagrass, for the seahorses to call home." Dr Harasti said.

"As a result of these habitats declining from the floods, the seahorses have suffered and as a result it is rare for divers to see this iconic species to the region now."

To help with the recovery of the species, DPI collected eight adult White's seahorses from Port Stephens in November 2022.

They were transported to Sea Life Sydney aquarium to be used as breeding stock.

The adult seahorses bred in captivity within days of their arrival, Dr Harasti said, and over the summer season they gave birth to more than 700 babies.

It is the fourth year that Sea Life has undertaken the seahorse breeding program, which is a collaboration between the aquarium, DPI and the University of Technology and began when the White's seahorse was listed as endangered.

"We are entering the fourth year of our breed and release program - the most successful year to date," Teagan Pyne, aquarist and seahorse expert at Sea Life Sydney Aquarium, said.

"They are an iconic species and act as ambassadors for the Sydney Harbour, drawing attending to multiple threats facing a number of species and the broader environment.

"They are important predators, helping to control populations for bottom dwelling organisms such as small invertebrates, and are a key food source for larger marine animals."

The captive-bred seahorses have now reached a suitable size to be released back into the wild.

Seven hundred juveniles will be released in Port Stephens and Sydney Harbour across May, June and July.

"This is where the breeding adults came from. We wanted to ensure genetics were consistent for both populations," Ms Pyne said.

The first 300 were released by Dr Harasti in Port Stephens on Wednesday, May 10.

"To assist with the their survival in the wild, artificial habitats have been built for the seahorses that are known as seahorse hotels," Dr Harasti said.

"These hotels are essential to provide a habitat as the flooding caused loss of many of the natural habitats that the seahorses use.

"These captive-bred seahorses will be released onto 30 custom made seahorse hotels, built locally in Salamander Bay, that were installed in March at the Pipeline dive site located off the d'Albora break wall.

"These hotels now have sufficient marine growth on them to provide habitat and food sources for the seahorses to thrive on."

Following their release, divers from DPI will regularly monitor the released seahorses at the pipeline site to assess their survival, growth and movements, plus the integrity of the hotels.

It is hoped that the released seahorses will live on the hotels and then come October, will start breeding which will help "lead to the recovery of this endangered species within Port Stephens," Dr Harasti said.

In line with the release of the 700 White's seahorses, Sea Life is calling on the public to play their role in saving the species by adopting one.

A new adoption package for $45 will go towards "making a real difference in saving an endangered animal".

"Our guests often ask how they can become involved in protecting the species. This is a tangible opportunity for the public to contribute to saving an enchanting species on their doorstep," Ms Pyne said.

"They money raised will be reinvested into the essential purpose built on-site facilities and the experts involved in saving the population."

For $45, the package includes a digital adoption certificate, inclusion of the seahorse's and the adoptee's name online and in the in-attraction honour roll and 12 months of regular updates on the seahorse program and other Sea Life initiatives.

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