Sea Search Expedition: Mud Islands

Photo Credit: Phillip Wierzbowski

Photo Credit: Phillip Wierzbowski

Do you love beach combing, puddling around in rock pools and snorkelling in seagrass beds looking for sea creatures? Ever wondered if there was a way for you to get more involved in caring for your local marine environment?

The Parks Victoria Sea Search program offers communities the opportunity to help contribute to our knowledge of intertidal marine ecosystems and the spread of marine pests. This is a great way to learn more about your local marine national park, while collecting scientific data that helps to inform its conservation!

Wild Melbourne recently set out with a Sea Search expedition to Mud Islands at the mouth of Port Phillip Bay to get a feel for marine survey methods. With 40 odd keen marine beans, we headed out from Queenscliff on the 62ft research vessel - the Pelican.

Mud Islands, Port Phillip Heads Marine National Park

mud island high tide heading home.JPG

Despite the drab name, Mud Islands, Port Phillip Heads Marine National Park, is an area rich in biodiversity, deserving of its RAMSAR “wetlands of international importance” status.

Three silt islands, ever-changing in size and shape, surround a protected lagoon, to which wading birds retreat at high tide. Saltbush and succulents top what I hesitate to call dunes; the highest point a mere 4 metres above sea level. Sand flats dominate the intertidal zone and support vast numbers of wading birds, some of which migrate here in their thousands from as far away as Alaska and Siberia.

Probing the fine sands at low tide with specialised bills, plovers, curlews, knots and godwits hunt for worms and molluscs hidden beneath. The islands also support great nesting colonies of pelicans, terns, ibis, silver gulls, storm petrels, cormorants and royal spoonbills.

Sharp Tailed Sandpiper

Sharp Tailed Sandpiper

Come the breeding season this place will be a cacophony of nesting birds, but in late summer the islands are much quieter, the landscape strewn with their bones and feathers.

Dip below the surface and seagrasses carpet the flats, teeming with life as they protect juvenile fish, squid, crustaceans and sea stars, as well as animals specialised for life within and upon the blades.

Fiddler rays nestle between the leaves, well camouflaged with their brindled skin and “I’m-not-here” attitude. These lawns provide a vital nursery for many species, including the commercially valuable King George whiting.

Sea Search Survey

We settle on the sand, geared up in our wetsuits and underwater cameras, to hear the history of the islands and learn about the different ecosystems we will be surveying. After a verbal introduction to our survey methods, we set off in groups to conduct seagrass surveys and targeted patrols for invasive species, all under the watchful eye of Parks Victoria rangers.

Unfortunately, we ran out of time to conduct a proper survey of the feathered community. Still, we found a moment to train our binoculars upon some of the waders hiding in the lagoon. 

Mud Island's Breath-taking Lagoon. 

Mud Island's Breath-taking Lagoon. 

An ecosystem under threat!

Our time on Mud Islands ends with a discussion of the threats to the islands and Port Phillip Bay at large. Sitting close to the mouth of the bay, Mud Islands collect rubbish, seeds, and excess nutrients from urban streets and farm runoff.

Miscellaneous plastic and metal pieces litter the beach, while stubborn weeds including boxthorn and kikuyu grass resist the equally stubborn weeding efforts of local care groups.

Excess nutrients have caused masses of algal growth to smother the vital sea-grasses, reducing water flow and preventing light from reaching the plants. Without sunlight, the grasses are unable to photosynthesize, and start to die.

All are a poignant reminder that we each have an impact on the health of our bay communities. Around three and a half million people live around Port Phillip Bay, and everything that lands on our streets or goes down the drain ends up here.

We return to the Pelican, but don’t head home just yet. No trip through these parts is complete without a visit to the Australian fur seals and Australasian gannets at Chinaman’s Hat and Pope’s Eye. We get up close and personal while learning about these charismatic bay characters, and then it is time to draw our adventure to a close.

As the sun breaks through the clouds, the sails are raised and we turn for home, our party blissfully soaking up the sun on the Pelican’s deck.

Would you like to attend events like this, or become more involved in learning about and protecting your local marine habitat?

To get involved with Parks Victoria’s Sea Search program, head to and send them an email at .

Both Sea Search and Parks Victoria can also be found on Facebook.

You can find out more about the SV Pelican at