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Chowder Bay
The seahorses were released by SIMS divers into artificial habitats known as ‘seahorse hotels’ as well as a nearby garden of kelp (Ecklonia radiata), which is abundant locally. This follows the installation of 20 seahorse hotels off Cockatoo Island’s Eastern Apron in July 2024. These mild steel structures become encrusted with algae, sponges and other organisms over time, providing seahorses with vital shelter as well as breeding grounds.
The Harbour Trust Chair, Tim Entwisle said, ‘White’s Seahorses have faced a dramatic decline due to the loss and degradation of habitat throughout their range. The Harbour Trust is delighted to be part of this innovative approach to conserve and boost the remaining populations of the seahorse at Cockatoo Island. This is a critical stop towards restoring populations of this iconic species across its native range along the Eastern Coast of Australia.’
The seahorse release follows months of careful breeding at the SIMS aquarium in Chowder Bay / Gooree, where researchers raised them from 3 pregnant males collected in October 2024. Unlike most marine species, male seahorses carry and give birth to their offspring, a unique reproductive trait that makes their conservation particularly fascinating.
The seahorse release is a key component of the Cockatoo Island / Wareamah marine restoration pilot project. The initiative aligns with the award-winning Cockatoo Island / Wareamah Master Plan, which prioritises scientific research and conservation efforts in the western harbour region.
With this latest release, we hope to not only boost the endangered White’s Seahorse numbers in Sydney Harbour but also create a blueprint for future marine restoration projects.
For more information on the Cockatoo Island Marine Restoration Pilot Project, visit the project page.
