The Sydney Seahorse Project

Reviving the Endangered White’s Seahorse in Chowder Bay

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In the tranquil, turquoise waters of Chowder Bay, a critical conservation effort is making waves. The Sydney Seahorse Project, initiated in late 2022, is renewing hope among the community for the endangered White’s seahorse, a species whose fate is tightly interwoven with the health of its marine habitat. 

Under the stewardship of Mitchell Brennan, a PhD candidate at the University of Technology Sydney and Project Manager at the Sydney Institute of Marine Science (SIMS), this ambitious project seeks to reverse the decline of White’s seahorse populations through innovative conservation strategies.

White's Seahorse. Photo: NSW Department of Primary Industries

A Fragile Icon of Marine Diversity

The White’s seahorse (Hippocampus whitei) is a unique marvel of marine biology. These seahorses, endemic to the eastern coast of Australia, are not just another fish in the sea. Their distinctive, horse-like appearance and the intriguing fact that it’s the males who carry and give birth to their young set them apart. 

Unfortunately, their populations have dwindled dramatically due to habitat loss and degradation. Recognised as the second seahorse species globally to be listed as endangered, the White’s seahorse is more than just a charming creature; it is a flagship species symbolising broader marine conservation challenges.

Chowder Bay: A Sanctuary for Revival

Chowder Bay, a protected estuarine area within the northern precinct of Sydney Harbour, has been chosen as the project’s focal point. This location is crucial for several reasons. Historically, Chowder Bay would have been adorned with lush seagrass meadows, which provided essential habitat for White’s seahorses. 

However, these natural habitats have been severely impacted by human activities. In response, the seahorses have adapted to using artificial structures like swimming nets for shelter. Chowder Bay, home to the SIMS aquarium, offers an optimal environment for the project’s efforts, including breeding and habitat restoration.

Mitchell Brennan and Seahorse. Photo: Tom Burd

At Chowder Bay, the team has installed 14 “seahorse hotels”, which are essentially artificial habitats designed to compensate for the loss of natural environments. These hotels are equipped with holdfasts for seahorses to anchor themselves, protection from predators, and a habitat conducive to the growth of micro-crustaceans, which are crucial for their diet.

A Labor of Love: Preparing for Release

The journey of each White’s seahorse is one of meticulous care and preparation. Rearing begins at the SIMS facility, where seahorses spend 4-6 months in a highly controlled environment. 

The team ensures optimal water quality and temperature, and the seahorses are fed multiple times a day. This phase is crucial for acclimating the seahorses to their future life in the wild.

Before their release, the seahorses undergo a gradual acclimatization process to match the conditions of Chowder Bay. They are then transported in special bags to the release site, where SCUBA divers carefully place them onto the seahorse hotels, swimming nets, or remaining seagrass patches. 

This transition is a delicate process aimed at minimizing stress and maximizing the chances of survival and successful adaptation.

The Enigmatic Life of Seahorses

The lifecycle of a White’s seahorse is as fascinating as its conservation story. With an average lifespan of about five years - though some can live over seven - these seahorses exhibit rapid growth. 

They reach sexual maturity within a year and are known for their monogamous breeding pairs. Their unique reproductive method, where the male seahorse carries and births the young, adds another layer of intrigue to their life cycle.

Looking Ahead: Future of Sydney Seahorse Project

The Sydney Seahorse Project is not resting on its laurels. Upcoming initiatives include the next breeding season, aligning with the natural breeding cycle of White’s seahorses, which runs from October to March. 

Seahorse Family. Photo: Jayne Jenkins

Additionally, the project is expanding its scope with a co-restoration effort alongside Operation Posidonia and Project Restore. This involves replanting seagrass fragments near seahorse hotels in Cobblers Bay and Balmoral, with plans to release seahorses in these newly restored areas by 2025.

Community engagement is a cornerstone of the project. On September 27th, the Sydney Seahorse Project, in collaboration with the Friends of Chowder Bay, will host a beach clean-up event open to the public. This event aims to foster a sense of stewardship and raise awareness about marine conservation.

How Can The Community Make a Difference?

The local community in Mosman can play a pivotal role in supporting the Sydney Seahorse Project. Residents are encouraged to participate in citizen science by submitting seahorse photos to iNaturalist.org, help keep the oceans clean by disposing of rubbish and fishing gear properly, and avoid damaging critical habitats like seagrass beds while boating. 

Donations to the project are also vital for sustaining ongoing research and conservation efforts.

As Mitchell Brennan and his team continue their work, the Sydney Seahorse Project stands as a testament to the power of dedicated conservation efforts. Through their innovative approaches and community involvement, they are not only working to save a species but also to restore the marine environment that sustains them. 

For those passionate about marine life and eager to support, following the project on social media @sydney_seahorse_project is a great way to stay informed & get involved.