In 2023, SIMS dived into the wonderful world of seahorses. A unique marine fish, seahorses are known for their wonder and myth-inspiring anatomy – in fact, their scientific name Hippocampus translates to “horse-like sea-monster”.  Seahorses are beloved creatures that can ignite a passion for the marine environment. However, like many marine fishes they face significant threats in a changing world. Seahorses rely heavily on their habitat, and decades of habitat degradation and loss has resulted in declining populations – notably the White’s Seahorse, Hippocampus whitei. H. whitei has been listed as an Endangered species due to reductions in wild populations greater than 95% in some areas, and immediate conservation action is required for the species to thrive.

In 2023, we saw the initiation of SIMS’ Sydney Seahorse Project (SSP). The project, a collaboration with the University of Technology Sydney and the New South Wales Department of Primary Industries (Fisheries), aims to conserve the Endangered White’s seahorse through a conservation stocking program, the installation of artificial habitat (seahorse hotels) and the restoration of natural habitats. The project has been generously funded by the Mosman Environmental Foundation, the Lim-Sutton Initiative and SailGP, and supported by the Gamay Rangers and Mosman Council.

SSP Project Manager, Mitchell Brennan, releasing the 2023 brood.
Jayne Jenkins.
One of the adults birthing fry just last week!

The project has a strong focus on the science required to improve the conservation outcomes for this Endangered species. During the breeding and rearing of the seahorses in 2023, our team of researchers led several experiments to optimise the growth rates, survival rates and overall fitness of the fish when held in the specialised aquarium facilities at SIMS, in an effort to increase their survival once released back into the wild. understated.

As a result of this husbandry approach, a total of 384 ‘super seahorses’ were released into Chowder Bay. These seahorses were tagged for identification, enabling both our researchers to track their monitor their survival, and facilitating a citizen-science initiative where local SCUBA divers can submit images to iNaturalist.

This valuable research was assisted by UTS honours student Courtney Ede and intern Diego Aponte Arevalo, their dedication to the project and contributions to its success cannot be understated.

Looking forward to 2024, we have just collected our seahorse broodstock to begin the seahorse breeding and rearing, with a research focus on pre-release conditioning (more to come!), and an expansion to release into Gamay (Boatny Bay). Alongside SailGP, we will be deploying seahorse hotels at additional sites within Sydney Harbour to ensure sufficient habitat for wild seahorse populations, and will be collaborating on the restoration of two Endangered habitats: the seagrass Posidonia australis alongside UNSW’s Operation Posidonia, and the soft coral Dendronephthya australis alongside the NSW DPI.

The project now welcomes Jillian Chambers to the team as a research assistant, who has a long history with the White’s seahorse having volunteered with the project in 2019 while completing her Master of Marine Science and Management. Jill’s years of experience as an aquarist and affinity for seahorses will play a major role in the project’s growth in 2024. The project also welcomes Maddie Vitnell as an undergraduate intern, who will be an asset to the team in assisting with husbandry and research.

We hope this is just the beginning for the conservation of White’s seahorses in Sydney Harbour and surrounding estuaries, and envision a time where populations have recovered to a point of stability.

Jill working with White’s seahorses back in 2019.