Welcome to Module 1
COASTAL SALTMARSHES
Welcome to the Coastal Saltmarshes module of Cradle Coast Natural Resource Management’s (NRM) online learning package. In this module, you will learn about Coastal Saltmarshes
- What are Costal Saltmarshes?
- Why Costal Saltmarshes are so important
- How and why Coastal Saltmarshes are under threat
- What you can do to help reduce the threats to Coastal Saltmarshes
This module will take you about 1 hour to complete
How to move through this online course
As you are guided through this module, you will learn about Coastal Saltmarshes through reading text and watching short videos.
At the end of this module there will be an electronic link to other modules about Short-tailed Shearwaters, Giant Freshwater Crayfish and Little Penguins.
What are Coastal Saltmarshes?
Coastal Saltmarshes are a special type of wetlands that occur on the boundaries between land and sea. They act as a dynamic sponge trapping fine mud particles and filtering water, nutrients and sediment as it runs off the land. Coastal Saltmarshes feature water channels and mud flats and grow in areas of tidal influence such as estuaries, bays and lagoons. They are places teeming with biodiversity and they provide important habitats for migratory and resident birds.
Coastal Saltmarshes are a Threatened Ecological Community (TEC), listed under the Environmental Protection and Biodiversity Conservation (EPBC) Act 1999, in Australia. There are areas of saltmarshes along the Cradle Coast region’s coasts; each has their own unique characteristics.
Watch this video to understand the dynamics of a Coastal Saltmarsh
How do they work?
Coastal Saltmarshes are confined to estuaries and inlets; near river mouths. As the sea comes in on the tide, wave action is subdued and sediments build up. This creates a rich accumulation of sand and mud, and highly saline water in some areas, making an ideal habitat for succulent herbs and shrubs. In other areas of Coastal Saltmarshes, where rivers and streams make the water less saline, non-succulent herbs and tussocks are prominent. This creates a variety of wetlands that numerous animal and plant species can use as their home. Coastal Saltmarshes can vary in size from a few metres wide up to several kilometres.
What does a healthy Coastal Saltmarsh look like?
Take a look at the image below to see what Coastal Saltmarshes are all about.
What are the benefits of healthy Coastal Saltmarshes?
Healthy Coastal Saltmarshes provide many benefits for plants, animals and humans, for example:
- Build land and hold and protect it from erosion
- Help keep the water clean and clear
- Are productive (provide vital habitats for many plants and animals)
- Help sustain recreational and commercial fisheries
- Provide carbon storage
- Are places that people value for recreation such as birdwatching
Let’s take a look at some Coastal Saltmarsh habitats
Each Coastal Saltmarsh habitat plays a role in building land, keeping water clean and providing specialised habitat for plants and animals, including many bird and fish species.
Melaleuca swamp forests
Melaleuca (Melaleuca ericifolia) swamp forests can be found on the edges of Coastal Saltmarshes. They form a canopy where sedge-dominated understorey plants can thrive and assist in stabilising sediment and maintaining water quality. Melaleuca swamp forests are listed as a threatened vegetation community in Tasmania under the Nature Conservation Act 2002, due to wide-spread land clearing post-colonisation.
Image credit: Jen Evans.
Intertidal flats
The intertidal zone is the area of land flooded at high water and exposed at low water. On each tidal cycle, about a billion tonnes of water comes and goes through the intertidal flats in the Circular Head area.
Image credit: Jen Evans.
Tidal channels
Tidal channels play an important role in reducing wave energy as well as providing habitat for sea life such as fish and invertebrates.
Seagrass beds
Seagrasses create and trap sediment, providing safe living places for fish, worms and crabs. The seagrass leaves are broken down by bacteria into detritus, which makes it easier for animals to digest. Seagrass beds continually take in carbon dioxide from the air and the sea and store it by converting it into living plant matter.
Image credit: Paul Asman and Jill Lenoble.
Coastal Saltmarshes are dynamic ecosystems
Have a look at one of the largest and important Coastal Saltmarsh areas in the Cradle Coast region: Boullanger Bay, Robbins Passage, Big Bay and Duck Bay. These Coastal Saltmarshes provide important and specialised habitats for many plants and animals. When you visit one of our Coastal Saltmarshes you will be able to see the dynamic nature of its ecosystems as the tides come and go.
Below is map showing Coastal Saltmarsh areas
(marked in pink) at Boullanger Bay, Robbins Passage, Big Bay and Duck Bay
Coastal Saltmarshes have diverse vegetation
Here is an image of the diverse vegetation types (Sea Lavender in full bloom) at the Big Bay Coastal Saltmarsh.
Image credit: Vishnu Prahalad.
and rich bird life
Migratory birds at Boullanger Bay include the Red-necked Stint (Calidris ruficollis), Ruddy Turnstone (Arenaria interpres), Curlew Sandpiper (Calidrus ferruginea), Red Knot (Calidrus canutus) and Sharp-tailed Sandpiper (Calidris acuminata).
Image credit: Vishnu Prahalad.
and are teeming with biodiversity
Ray in seagrass wetlands at Boullanger Bay.
Image credit: Richard Mount.
Why are Coastal Saltmarshes so important?
Coastal Saltmarshes are an important ecological community for the following reasons:
- Provide feeding habitat for migratory and resident birds, several of which are threatened, endangered or critically endangered
- Filter nutrients and sediments
- Work as a fish nursery for both commercial and recreational species
- Help reduce impacts from storm damage and floods
- Act as a carbon sink
- Contain several rare and threatened plants
- Contribute significant amounts of organic material to estuaries, creating important food chains
A vital home for many birds
Coastal Saltmarshes in the Cradle Coast region provide vital feeding habitat for migratory and resident birds, some of which are threatened, endangered and critically endangered, for example:
Orange-bellied Parrot - migratory
(Neophema chrysogaster)
Conservation status: Critically Endangered
...and watch this short video
Image credit: JJ Harrison.
Eastern Curlew - migratory
(Numenius madagascariensis)
Conservation status: Critically Endangered
See what an expert says about the Eastern Curlew, the largest migratory bird in the world
Image credit: Dick Daniels.
Red-necked Stint - migratory
(Calidris ruficollis)
Conservation status: Near Threatened
Take a look at this footage of Red-necked Stints close up
Image credit: JJ Harrison.
Red Knot - migratory
(Calidris canutus)
Conservation status: Near Threatened
Find out more about this cute bird
Image credit: Chuck Homler.
Bar-tailed Godwit - migratory
(Limosa lapponica)
Conservation status: Near Threatened
Sit back for 5 minutes and learn about Godwit habitat
Image credit: Andreas Trepte.
Curlew Sandpiper - migratory
(Calidris ferruginea)
Conservation status: Near Threatened
Image credit: Davidvraju.
Pied Oystercatcher
(Haematopus longirostris)
Conservation status: Least Concern
Here's a clip about Oystercatchers
Image credit: JJ Harrison.
Banded Stilt
(Cladorhynchus leucocephalus)
Conservation status: Least Concern
Watch a brief clip about Banded Stilt behaviour
Image credit: Helenabella.
Swamp Harrier
(Circus approximans)
Conservation status: Least Concern
And finally a video about Swamp Harriers
Image credit: JJ Harrison.
A home for specialised plants
Coastal Saltmarshes support highly specialised plant species which have adapted to excess salt and waterlogging. Healthy plants play a central role in structuring Coastal Saltmarsh ecosystems and provide habitat for animals. Coastal Saltmarshes have different zones which provide specialised habitats for plants and animals.
Take a look at the graphic below to get an idea of the different zones and the lifeforms they support
Near the mouths of estuaries and inlets, where the inundating water is highly saline, Saltmarshes are dominated by succulent herbs and shrubs.
The most common succulent herb is the Beaded Glasswort (Sarcocornia blackiana) shown left and a common succulent shrub is Shrub Glasswort (Tecticornia arbuscula) shown below.
Coastal Saltmarshes are fish nurseries
During high tides, fish shelter and feed on food derived from crabs, snails, insects and microalgae. Up to 12 species of fish have been recorded in Coastal Saltmarshes in Circular Head, with densities of up to 72 fish found within an area of 100 square metres, which is the highest density recorded in Australia. Three species which are important to commercial and recreational fisheries are present:
Who else lives in Coastal Saltmarshes?
Snails
Salinator solida
Image credit: John and Maria Grist
Tatea rufilabris
Image credit: Des Beechey
Crabs
Haswell’s Crab (Helograpsus haswellianus)
Image credit: Museum of Victoria
Haswell’s Crab (Helograpsus haswellianus)
Image credit: Kris McCraken
Insects and spiders
A wide variety of insects and spiders can be found in Coastal Saltmarshes. They form an important part of the saltmarsh foodweb and their abundance usually varies over seasons.
Tasmanian Wolf Spider (Tasmanicosa godeffroyi)
Image credit: David Paul / Museums Victoria
Tasmanian Darner (Austroaeschna tasmanica)
Image credit: JJ Harrison
More great things to know about Coastal Saltmarshes
Coastal Saltmarshes can be live classrooms for students and are great places to connect and learn about nature. They can provide a rich living laboratory for scientific research and development.
The upland vegetation that surrounds Coastal Saltmarshes provides important and diverse habitat for plants and animals. Upland vegetation improves water quality and coastal productivity.
The water that runs-off the land is slowed down and filtered by saltmarsh and native vegetation. This improves estuary water quality and benefits the nearby submerged aquatic vegetation.
Tidal creeks are an integral part of saltmarshes and form branched networks within larger marshes. They provide habitat for fish and invertebrates and channel and dissipate wave energy.
Saltmarshes provide a buffer by soaking up floodwater and regulating water flow. This helps protect low lying human assets from flooding events and sea level rise.
Saltmarsh soil forms as the plants trap fine sediment (sand and mud) and organic particles generated by both plants and animals. This soil-building process helps remove carbon from the atmosphere, storing it until the sediment is disturbed.
Disturbance of tidal marshes due to land reclamation has been shown to be an important source of atmospheric CO2, which has previously been mostly ignored in international carbon accounting calculations (Ewers Lewis et al, 2019).
Saltmarshes are important elsewhere too
Watch these videos to learn more
Coastal Saltmarshes are vulnerable
The ecological community of Subtropical and Temperate Coastal Saltmarsh is listed as Vulnerable under the EPBC Act (1999). The Coastal Saltmarshes in the Cradle Coast region are categorised as temperate.
Here is a map showing the areas of Subtropical and Temperate Coastal Saltmarsh in Australia
Where do Coastal Saltmarshes occur in the Cradle Coast region?
Coastal Saltmarshes have the highest concentration in the Circular Head area of the Cradle Coast region. There are small areas of Coastal Saltmarshes on King Island, on the west coast near Strahan and the Henty Dunes, and at Port Sorell-Rubicon, Mersey-Don, Forth-Leven, Blythe-Cam, Detention-Black Rivers on the north-west coast.
It is estimated that there is approximately 6640 ha of Coastal Saltmarsh in Tasmania; 1750 ha in the Cradle Coast region, 1473 ha in the Northern region and 3419 in the Southern region. Coastal Saltmarsh in the Circular Head area makes up 20% of the total area of Coastal Saltmarsh in Tasmania and 76% of the total area in the Cradle Coast region*. The largest areas of Coastal Saltmarsh in the Circular Head area are located at Robbins Passage, totalling 327 ha.
*This based on the figures provided by Cradle Coast NRM 2016; NRM North 2014 and NRM South 2013.
What are the greatest threats to Coastal Saltmarshes?
The greatest threats to this valuable ecosystem include:
- Land clearing and fragmentation
- Inappropriate development (landfill, land reclamation, construction of tidal levees)
- Invasive species such as Spartina Anglica (Rice Grass or Cord Grass)
- Pollution and litter
- Grazing by livestock
- Climate change
10 things you can do to help keep Coastal Saltmarsh healthy
- Fencing to exclude stock and vehicles
- Creating buffer zones with appropriate plant species
- Raising community awareness of the importance of saltmarsh areas
- Better land use practices
- Having consideration when enjoying recreational activities
- Cleaning up litter and debris
- Do your bit to reduce marine debris take your rubbish home, join in local beach clean-ups and get involved in ‘Plastic Free July’ and ‘Take 3 for the sea!’
- Vigilance with weed control and follow up
- Supporting local efforts to conserve threatened species in your area by joining a local Landcare or a 'friends of' group
- Participating in special community events, information sessions, tree planting days and weed eradication programs
Take 3 for the Sea
‘Take 3 for the sea’ is global movement aimed at inspiring you to take 3 pieces of rubbish with you when you leave the beach, waterway or anywhere.
Plastic Free July
Launched in 2011 by Perth's Western Metropolitan Regional Council, Plastic Free July aims to educate the public on the problems plastic causes.
Remember the 3 Rs?
You will probably remember learning about the 3 R’s when you were growing up; reduce, reuse and recycle. This philosophy is still important today, and even more so with the ever-increasing negative effects that plastics are having on our marine environment.
Want to do your bit to reduce plastic debris before it enters our oceans?
Take a look at this infographic to learn about the impacts of plastic debris and how you can do your bit to reduce plastic debris from entering the ocean:
Want to know what’s happening in our region to fight marine debris?
Want to go ahead and join a group and make a difference?
And you can make a difference by participating in projects supported by Cradle Coast NRM which we will advertise in our newsletter, on our website, or via our Facebook site.
Greening Australia also has opportunities
What if I own or manage land that is or near Coastal Saltmarsh?
If you own or manage land that is or near Coastal Saltmarsh, here are some things that you can do to help keep it healthy:
- Don’t clear or remove native vegetation along stream banks, shorelines and wetlands
- Only use chemical sprays which are registered as suitable in watercourses
- Fence your stock out of your waterways and near wetlands, as they will muddy the water and degrade river beds and make it unviable for saltmarsh species to thrive
- Plan your fencing so that you can completely exclude stock from waterways and wetland edges
- Plant native vegetation (especially trees) along stream banks
- Consider seeking help to sustainably manage and conserve your Coastal Saltmarsh habitat through the Private Land Conservation Program by clicking below:
Here’s two links to more info about managing stock near waterways
Want to know more about Coastal Saltmarsh?
Take a look at the following links to learn more about the biodiversity, management, conservation and monitoring of Coastal Saltmarshes:
What is Cradle Coast NRM doing to help keep Coastal Saltmarsh healthy?
Cradle Coast NRM are starting a coastal saltmarsh protection project soon. Contact Cradle Coast NRM for an update and to find out more about Coastal Saltmarshes and how you can get involved.
Before you go, let’s recap on the key learnings from this module. In this module, you have learnt about Coastal Saltmarshes:
- What Coastal Saltmarshes are
- Why Coastal Saltmarshes are so important
- Where Coastal Saltmarshes occur
- What you can do to help reduce the threats to Coastal Saltmarsh habitats
- What you can do to help keep Coastal Saltmarshes healthy
You will have learnt about the options for getting involved to make a difference:
:
Are you interested in learning about other important species in the Cradle Coast region?
We have developed other online learning modules
GIANT FRESHWATER CRAYFISH
LITTLE PENGUINS
SHORT-TAILED SHEARWATERS
Credits:
Created with images by flownaksala - "Great Blue Heron enjoying a golden Chesapeake Bay sunset" • Kamil Ślusarczyk - "untitled image" • herbert2512 - "sunset moor venn" • 13082 - "penguin fairy penguin bird" • 11066063 - "penguin zoo bird" • 1STunningART - "businessman's rocket speed" • Ryan Walton - "untitled image" • tiero - "hurry to start" • Tito Rebellious - "untitled image" • Almos Bechtold - "untitled image" • Epicurrence - "untitled image" • StephanieAlbert - "cows freedom beach" • adege - "garbage plastic waste beach" • James Wainscoat - "untitled image" • Michael Martinelli - "untitled image" • ChrisBeePixel - "cow cows lake" • bones64 - "bird seagull marshland" • petraboekhoff - "salt marshes north sea watts" • monicaclick - "cute pug puppy dog with pink party hat and horn and old blue wooden sign with festive hip hip hooray banner, isolated on white background" • John Schnobrich - "untitled image" • Miguelangel Miquelena - "untitled image" • Fahrul Azmi - "untitled image"