Tasmania is known for its beautiful forests, mountains and beaches. Less appreciated are its saltmarsh wetlands.
- Vishnu Prahalad wants saltmarsh environments to be appreciated as much as Tasmania’s forests and beaches
- Saltmarsh habitats are important for the many birds, fish and insects they support, and for pollution and flood control
- There are examples of saltmarsh habitat being restored in recognition of their value
Vishnu Prahalad wants to change that.
The University of Tasmania geography lecturer is passionate about the state’s coastal wetlands, not just because he finds them so interesting to be in, but also because they play a vital role in pollution control and flood management.
“There’s lots of biodiversity in [wetlands] — lots of birds, fish, crabs, snails,” Dr Prahalad said.
“They’re called ‘blue carbon’ ecosystems because they pull back carbon from the atmosphere and store them in their soils and vegetation, they’re important flood buffers … [and] they’re also really important for improving water quality.
Windermere Bay at Claremont, north of Hobart, is home to a remnant saltmarsh.(ABC News: Loretta Lohberger)
“To appreciate that we probably need to look at them with a different set of lenses … we look at forests and mountains and think of them as our natural environments, so we do need to change those lenses and get down to their level.
“Often we need to get down on our knees to appreciate saltmarshes in their own right.”
Derwent Estuary Program chief executive Ursula Taylor said saltmarshes were “beautiful places and not well known about”.
Derwent Estuary Program chief executive Ursula Taylor says there’s a growing appreciation of how special saltmarsh wetlands are.(ABC News: Loretta Lohberger)
The largest area of healthy saltmarsh is in the southern part of the estuary at Lauderdale, but throughout the estuary, work is being done to protect and repair saltmarsh habitat.
“There’s a growing realisation of how special these places are and I’m really excited to see that councils like Glenorchy are looking after their saltmarsh by changing their mowing regimes and providing suitable access for people to go and visit them without disturbing the saltmarsh itself, and keeping an eye on it, and I know local communities and their Coast Care groups are doing the same sort of thing,” Ms Taylor said.
Glenorchy City Council environment officer Adam Muyt said the council had been actively managing the saltmarsh at Windermere Bay at Claremont for the past five years.
Walking tracks allow people to enjoy saltmarsh areas, which are rich in biodiversity.(ABC News: Loretta Lohberger)
The work has included weed removal and not mowing as close to the river so that the saltmarsh can expand.
“This area could just be walked on, driven on, and this is what was happening. The foreshore was essentially getting trashed,” Mr Muyt said.
He said it did not take long after vehicles were stopped from driving on the foreshore for the saltmarsh to recover.
“This is a classic example where we may have spent money over the last five years on weeding, but when it comes to allowing the saltmarsh to enlarge, it’s been very simple.”
Glenorchy City Council says a constructed wetland that treats the water from nearby shops and streets has improved water quality in Windermere Bay.(ABC News: Loretta Lohberger)
Windermere Bay also includes a constructed wetland, which captures the stormwater from the Claremont shopping centre and nearby streets.
Mr Muyt said the pollutants in the water settle in a bed that has been planted with native species.
“It basically allows all the pollutants to settle out into this bed or be absorbed by the plants and that helps to clean the water, filter the water as it moves into the bay,” he said.
“It’s now coming up to eight years and the water quality here, as monitored by the Derwent Estuary Program, indicates that the water quality has improved to the point where it’s even swimmable just around the corner.”
He said eventually the bed would need to be cleaned out using machinery, but it would be another five years before that would be needed.
Glenorchy City Council has plans to install signage to increase awareness of the importance of saltmarsh habitat.
Brighton Council has similar plans.
More than 100 bird species, including the Australian penguin, use saltmarsh ecosystems.(ABC News: Loretta Lohberger)
Brighton Council general manager James Dryburgh said the Old Beach saltmarsh had long been recognised as important as a recreation area and for its environmental values.
“That deeper understanding of just how important those ecological values are is something that’s a bit more recent. Often you don’t notice what’s on your doorstep,” Mr Dryburgh said.
“We’re looking at doing some work on sea level rise modelling, specifically in this area and a couple of other areas that are particularly low lying and we want to get a better understanding of what the future holds — the saltmarshes are creeping inland.
“There’s a number of reasons for doing it, it’s protecting the environment but it’s also managing that interface with the residential properties nearby.”
Dr Prahalad says saltmarshes are important for fish.(ABC News: Loretta Lohberger)
Many of the Derwent’s remnant saltmarshes, like most of what is found in the Brighton Council area, are on public land.
“In the Derwent we’ve lost about 25 per cent of these habitats, which is better even than Launceston and other parts of the world where we’ve lost 50-70 per cent of these habitats in the urban environment,” Dr Prahalad said.
“We’re very lucky to have this.”
He said there were still some areas where saltmarsh environments were being filled in for development.
“It’s really important for us to engage with the local council and the relevant landowners to work out how we can reduce or prevent that from happening.”
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