Western Port Phillip Bay

Trial Site - Installed November 2018


Melbourne Water’s Western Treatment Plant, and adjacent coast have been long renowned as a significant habitat for shorebirds and waterbirds (Rogers et al 2013). It is listed as a BirdLife International Important Bird Area, East Asian-Australasian Shorebird Site Network Site and is the most significant habitat within the Western Port Philip and Bellarine Peninsula Wetland of International Importance (listed under the Ramsar Convention).

Although Melbourne Water maintains a system of lagoons for shorebird conservation, coastal high-tide roost sites have become jeopardized by sea-level rise and increased storm events.

SCROLL DOWN FOR UPDATES (oldest at the bottom).

text photos and footage Chris Purnell

Red-necked Stints landing at a rocky roost on the Western Treatment Plant coastline.

Red-necked Stints landing at a rocky roost on the Western Treatment Plant coastline.

February 22 2019, it’s a new year… the Year of the ROOSTER!

It’s been a busy summer down at the roosts; heat waves, storms and a visit from a very popular Eurasian vagrant threw a lot of challenges at WTP’s waterbirds over the Christmas break.

Site Update

T-Section Pond 6 (non-tidal, freshwater pond)

Ducks have been ruling the roost down at the T-Section! Chestnut Teal, Pink-eared Duck, Australian Shellduck and others have been taking up most of the real estate at the site, however Sharp-tailed Sandpipers and Red-necked Stint are always welcome, meandering through the ducks, feeding or simply roosting on among the gaps.

White-faced Herons, Great Egrets and terns have also been observed on the roost. While Royal Spoonbills, Black-winged Stilts and Red-necked Avocets use the spaces between the bags as their own personal supermarket isles, deftly feeding on invertebrates in the water column that have either come off the bags or become concentrated in the “bag field”.

The new year brought with it Australia’s first recorded Tufted Duck. “Tufty” as it came to be known, chose to take up residents in neighboring ponds to the trial. As celebrity status grew hordes of twitchers, film crews and paparazi were drawn to the T-section hoping for a glimpse. this provided a great opportunity to observe how birds responded to disturbance from the saftey of the roost (20m from the road).

As the summer ground on the T-section pond dried… and dried………. and dried. The bags are now sitting on the mud but Sharpies continue to feed on and around them.

The Spit NCR (sheltered tidal lagoon)

The sheltered waters within the northern Spit have been getting regular visitation from a faithful Greenshank and a flock of around 10 Sharp-tailed Sandpipers. Nightfall often brings small flocks of Shellduck.

With drying ponds in the neighboring Western lagoon exposing their own suite of exquisite roosting opportunities the floating roosts are currently playing second fiddle.

Little River south (intertidal)

A large algal bloom during the Christmas period changed the landscape around the Little River roost and surrounding coastlines. Sheets of beach-cast algae provided hectares of lush green, wet, natural floating roosts and feeding areas… perfect for shorebirds! However despite these options flocks of terns, gulls, ducks and sandpipers return to the floating roost tide after tide. Some terns would even remain roosting on the bags at low tide as Sharp-tailed Sandpipers continued to feed on and around the roost.

December 6 2018, Early colonisation

The three floating roosts at the Werribee Treatment plant have now been in place for two weeks and colonisation has begun! Both above and below the water. Given the varying conditions and localised waterbird populations we’ve seen some early differences between the 3 sites – the trend-setters, the invertebrate response and how birds use the roosts.


Site Update

T-Section Pond 6 (non-tidal, freshwater pond)

Chestnut Teal were the early adopters. With a solitary bird observed on day 2, we now regularly observe up to 20 birds. Whiskered Tern feed around the bag field perhaps taking advantage of localised eddies of water which concentrate invertebrates in the water column*, and roosting in small numbers. Algae has begun to coat the shells and bags providing a novel food source for our first shorebird visitors, Sharp-tailed Sandpiper.  

*CEE consultants will look at invertebrate distributions as part of our parallel study into the ecological effect of the trial.

The Spit NCR (sheltered tidal lagoon)

Although not as popular (yet) high-tide brings in a small list of regulars including Common Greenshank and Sharp-tailed Sandpipers which are using the site for both roosting and to continue feed throughout the tide cycle. Although the sediment in this basin at the northern spit is extremely soft, the water (when undisturbed) is crystal clear and small fish have been observed sheltering in the bag field.

Little River south (intertidal)

The sea has been rough my friends. This roost has copped a battering, but has withstood. At first merely a curiosity to most, the only use this roost seemed to serve was to concentrate invertebrates on the windward side for opportunistic Avocets perusing the aisles and feeding in the water column. Then in the heat of the day, two hours before high tide, a single Whiskered Tern became an influencer. Compatriots leaving nearby beaches and sand spits would hover over the tern calling. Initially, some would land but more would move on. However, as the water began to rise more and more would return often visibly hot, mouths agape and land, wetting their feet and settling in. Before long over 150 individuals including Crested Tern, Whiskered Tern, Silver Gull and Red-necked Stint were roosting on the bags bobbing in the bay and attracting attention from curious patrols of Pelicans.

Data collection

The observations above have been made on my few visits to the sites over the last couple of weeks or via the one remote Arlo camera installed at T-section. They are fleeting and I no doubt miss a lot as the trials or only targeted at providing temporary, supplementary roosting during high tide. While we hope to install cameras at each site and have the capability to stream this footage live through the mobile network, resolution is not very high.

This is where you can help out!

Datasheets (found here) have been placed at all three roost sites (map here). If observers would like to contribute data they can do so using the following method:

  • Standing at or near to the accompanying sign count all birds observed on the roost in a 10 minute period. Note species, position, and count (by bag), as on datasheet.

  • The floating roosts are designed to provide supplementary high-tide roosting opportunities, so surveys should ideally be conduct at or close to high tide. Opportunistic surveys outside this window are also welcome (including 0 counts!).

  • If you revisit the same site more than once in the same tide cycle multiple 10 minute surveys can be submitted.

  • Temperature and wind conditions are useful variables in identifying why the roost may or may not be used at the time of surveying. Please provide your best indication. Your phone’s weather report for Pt Wilson will do.

Submitting your data

Data will be entered manually so if you are not submitting a Floating Roast Trial datasheet please try and record the fields in a consistent with those outlined above.

  • Snap: email a photo of your notebook

  • Print and Scan: print the datasheet, fill it in, scan it and email it back.

  • Post: send your datasheets (on bulk or singles) to Post: send your datasheets (on bulk or singles) to Chris Purnell, Birdlife Australia, Suite 2-05, 60 Leicester Street, Carlton VIC 3053.


You may notice a few tags on the bags or attached via red screw anchors at nearby natural roosts, these are project thermologgers (contained within black pill boxes). Charged with the task of monitoring the temperature at the roosts they’ll hopefully give us an insight into roost selection/preference. Please let me know if you see any go wayward.

Please don’t hesitate to get in touch with queries comments and feedback.

Thanks again to Melbourne Water and Parks Vic for continued support.

- ChrisP

November 22 2018. We’re afloat!

The first Floating Roost Trial has been successfully rolled-out across three sites at Melbourne Water’s Western Treatment Plant and Parks Vic’s Spit Conservation Reserve.

A small team undertook a Herculean effort across two days to install the roosts. We managed to skirt all the major storms, banjo sharks and clouds of Sharpies to install 360 bags across the northern Spit CR, T-Section pond 6 and the coast south of the Little River Bird Hide.

Consultants conducted pre-assessments on the intertidal ecology around the bags and we have deployed thermologgers to assess the thermal properties of the roosts in collaboration with Deakin University. We have installed remote cameras to monitor the colonisation of the roosts and can already see that ducks, terns and the occasional sandpiper are using the sites! In addition, we will rely on observer records. Read more about how you can submit data here.

Thank you to our major sponsors, and Birdlife Melbourne, as well as Parks Victoria and Melbourne Water for their continued support across the sites. Thanks also to The Nature Conservancy for providing the oyster shell.

Kangaroo Island oyster farmer Bob Nicholson, out the final touches on the Spit NCR roost.

Kangaroo Island oyster farmer Bob Nicholson, out the final touches on the Spit NCR roost.

Chris Purnell