Video: Spartina management in the Westernport Catchment
Melbourne Water has launched a ten-year management plan to help control the introduced plant, Spartina.
Speaker 1 - S1 (Tom Hurst)
Speaker 2 - S2 (John Kershaw)
Speaker 3 - S3 (Alanna Wright)
Speaker 4 - S4 (Danial Robbins)
[Melbourne Water logo]
[On-screen text: In 2017, Melbourne Water is commencing the first year of a 10 year management plan to eradicate Spartina in Western Port.]
[Map showing distribution of Spartina in Western Port: concentrated in the management areas of The Inlets, Bunyip River, Yallock Cut & Levee, Jam Jerrup, Bluff Road, Bass River and Bass South.]
[On-screen text: Tom Hurst, Melbourne Water]
S1: Western Port’s a pretty special place. It’s a fair bit different to Port Phillip Bay, partly because it’s got two giant islands in the middle of it: French Island and Phillip Island. It’s got a very large tidal range, so when the tide goes out here it exposes huge areas of mudflats. And that’s one of the really important habitats that Western Port’s known for.
[On-screen text: John Kershaw, Senior Botanist, Ecology Australia]
S2: Spartina anglica – and its common name’s ‘common cordgrass’ – it’s a grass species of estuarine environments and it occurs predominantly within the intertidal zone.
S2: It initially starts off as a small tussock, and over time that grows radially – so it’s rhizomatous: it’s got underground stems that grow outwards. So these plants grow into a big tussock, and when you get large infestations, they rapidly grow together to sort of form a dense wad with pretty much 100 percent cover. And that excludes all other plant species.
[On-screen text: Alanna Wright, Melbourne Water]
S3: People might ask, ‘why is Melbourne Water flying around in a helicopter to manage this weed?’ And we've got quite a few obligations that also come under that. So we’ve got Ramsar obligations, and also EPBC Act – so that’s environmentally protected species.
[On-screen text: The Ramsar Convention: The intergovernmental treaty that provides the framework for the conservation and wise use of wetland and their resources]
[On-screen text: E.P.B.C.: Environmental Protection and Biodiversity Conservation Act.]
S3: What we’re really trying to do is protect the intertidal flats and the habitat that that provides for shoreline bird species, but also the native vegetation that’s there.
S2: Spartina colonises the mudflats which are important habitat for a range of faunal species – so for fish breeding, and for wader birds and some migratory species. So it then disrupts their food webs, and this can have flow-on effects ecologically and even commercially.
S1: The mudflats are really important for the wading birds; they get out there when the tides are low, and poke around and get the food that they need. Spartina really invades those intertidal habitats. One of the main reasons we want to get rid of it is because it occupies space that is important for those species, and you know, the fundamental reasons why it’s such an important international wetland.
[On-screen text: Danial Robbins, Project Manager, Melbourne Water]
S4: I’m the project manager, I’m involved with the Spartina control in Western Port Bay with Melbourne Water. My role is to deliver the on ground works, which is the aerial spraying and the ground spraying.
S4: So the aerial spraying involves the helicopter. The helicopter’s basically got a 200-litre chemical tank on it, which delivers the chemicals to the Spartina through a snorkel. So the snorkel’s a long eight-metre pipe that runs off the helicopter, and it’s got a funnel at the bottom which directly targets the chemical. And it delivers larger droplet sizes – so that eliminates the spray drift for overspray on off-target spray.
S4: We work with the tides, and the weather of course, so we can’t have wind speed above 18 kilometres an hour. We do the ground spraying generally following up, probably about four weeks after the aerial spray, to see what we can control, what the helicopters basically missed. The ground spraying involves knapsack use on foot and we also do boat spraying from a canoe.
S3: When it comes to the success of this project, we really are going to rely on the land holders – and that includes the private and the public land holders. We want to work together with them so that we can get the ultimate goal of this project, which is eradication.
S3: That means keeping communication up with them, talking to them, getting them involved with monitoring, and just an overall understanding of what it is we’re trying to do. But it’s also important because we’re going to be there for a long time, and we intend to be doing this for the next 10 years until we can really hit that eradication level.
[On-screen text: Thanks to Parks Victoria, Ecology Australia, Birdlife Australia]