Wonders of the bays

Come and see the bays' colour

We invite you to take a look at the treasure trove in and around the bays

Port Phillip Bay and Western Port are home to a wildly diverse, colourful and fascinating marine wonderland. In this section, we've picked some of our favourite stories which we've discovered on our journey to understanding the bays.

From a creepy crawly army of crustaceans, to male baby bumps and sex-changing fish, our bays really are a treasure trove. But you mustn’t miss the collection of photos that capture gently swaying seaweed, nursing a multitude of fish and hedged by corals, hydroids and ascidians.

Above the water there’s a rich natural heritage of migratory birds, and those that stay closer to home all year around. The birds and their habitat are so special, that the area is recognised internationally under the Ramsar Convention.


Catostylus mosaicus: blue blubber
Catostylus mosaicus: blue blubber. Image credit - Julian Finn, Museums Victoria
Gardens at The Heads

Situated at The Heads in Port Phillip Bay sits a canyon which marks the historical course of the Yarra Valley.

The spider crab army

Each winter, an army of spiders crabs migrate to Rye Pier to shed their shells. 

The sea floor is transformed into a underwater scene from a film like 'Lord of the Rings', strange, mythical type creatures bearing down in a parade predators overwhelmed by their sheer size in numbers. In fact marine scientists, can only conclude that this is the reason the crabs moult in such huge quantities; their flesh is quite vulnerable to predators until their new shells harden.

Male pregnancies and the seadragon

Seadragons are commonly found around rocky reefs and piers surrounded by protective seaweed.

It has marine scientists stumped as to how but procreation between a female and male seadragon involves the female transferring her eggs on to the underside of the male's tail, where he will incubate the them until they are ready for birth. When the baby seadragons are ready to be born, the male's tail will twitch, and twitch again, and then suddenly his babies will burst out into the current.

*Update - on Thursday, 24 August 2017, ABC Online reported that photographer and keen diver, Pang Quong, caught a female weedy seadragon transferring her eggs to a male. It's believed that this is the first time ever that the process has been witnessed by humans.

Gender fluid fish

Western blue groper

We talk about climate change a lot throughout this website. So you'll either already or will soon will be accustomed to the idea that environments move and change ... incrementally and measured in millions of years through pre-history and then at the far more rapid pace of which we're seeing now.

One aspect of this change, is spotting species never before seen in the bays' waters. Citizen scientists were some of the first to discover the western blue groper taking residence in the bays.

The western blue groper are fascinating, gentle giants of the seas and can grow up to 175 cm. They start life as female and change sex when they reach about 30-35 years old ... that's right, they also live to a ripe old age to boot, up to 70 years of age.

Achoerodus gouldii: western blue groper. Image credit - Sue Morrison, Western Australian Museum
Citizen science

REDMAP is a way for people who live around, and visit, the coasts to share sightings of marine species that are ‘uncommon’ to the local area. 

As our climate changes, so too do the movements of our fish and this makes it pretty difficult for researchers to keep track! But with the help of numerous extra eyes, scientists can follow each species to help maintain their healthy populations.

Bird calls from the Western Treatment Plant