15/03/2026
What if I told you that one of the worldâs most unusual reefs lies just a short drive from Melbourne?
Our third and final dive of the VSAG Labour Day long weekend took us somewhere quite special: the bryozoan reefs of the Eastern Arm in Western Port.
Very few people realise that we have such an unusual ecosystem right on our doorstep! These ecosystems are not rocky reefs, and they are not coral reefs â they are bryozoan reefs. In fact, Western Port hosts several of them, and they are considered globally significant.
In a previous role I had worked with Drs Travis Dutka (La Trobe University) and Adrian Flynn (Fathom Pacific) who described these habitats in the Eastern Arm back in 2022. Later, I worked with them to document the bryozoan habitats in the North and Western Arms of Western Port, which look quite different. Until now, though, I had only ever seen these environments through ROV (Remotely Operated Vehicle) and GoPro footage. I had never actually dived on either of these reefs, so I was thrilled when the opportunity came up with VSAG.
The dive itself was a little spooky; visibility was poor and the landscape felt otherworldly, but it was absolutely worth it. The reefs are dominated by two bryozoans: the delicate cream-coloured âwhite lace coralâ, forming intricate, wavy sheets, and the less abundant but more robust âorange plate bryozoanâ.
Among the bryozoan structures we found a range of life: several sea star species, doughboy scallops, a sea spider, a sea slug, pencil sea urchins, and plenty of colourful sponges and ascidians tucked among the colonies.
Anyone diving these reefs should be extremely mindful of their buoyancy and avoid anchoring. These habitats are fragile, ancient, and likely recover very slowly from disturbance â if they recover at all.
You can see examples of the diversity of life we found here: https://shorturl.at/cLTSQ