What is it?

Coastal Saltmarsh is an intertidal vegetative community comprising of salt tolerant vegetation. It is typically structured as a closed to open herbland and grassland, occasionally with emergent shrubs.

Coastal Saltmarsh is comprised of halophytes a group of salt tolerant succulent herbs and low succulent scrubs, rushes and sedges. They are able to tolerate extremes of environmental conditions, most notably waterlogging and salinity.

What plants do you find there?

The characteristic species of Coastal Saltmarsh are listed below and include Sporobolus and Sarcocornia species. Occasionally mangroves (including the Grey and River Mangrove) can be found scattered through the Saltmarsh along with tall reeds and salt pans. The species composition of Coastal Saltmarsh is directly affected by site elevation and patterns (frequency and duration) of tidal inundation with different species having varying levels of salt tolerance.

• Baumea juncea - Bare Twig-rush
• Juncus krausii - Sea Rush
• Sarcocornia quinqueflora - Beaded Samphire / Glasswort
• Sporobolus virginicus - Marine Couch
• Triglochin striata - Streaked Arrowgrass
• Isolepis nodosa - Knobby Club-rush
• Samolus repens - Creeping Brookweed
• Selliera radicans - Swamp Weed
• Suaeda australis - Austral Seablite
• Zoysia macrantha - Prickly Couch

Where do you find it?

Coastal Saltmarsh can be found in the intertidal zones on the shores of estuaries and saltwater lagoons around Pittwater. They include:

• Winnererremy Bay
• Careel Bay
• Refuge Cove
• Saltpan Cove
• Winji Jimmi

Coastal Saltmarsh is frequently found as a zone on the landward side of mangrove stands typically between the Mean High Tide and the King Tide marks. It survives in a niche created by the hyper saline conditions that restricts terrestrial species, and the lack of regular tidal flushing that restricts mangrove species.

What does it look like?

Coastal Saltmarsh can have a range of varying appearances. It is typically found as an open area of mudflat that is vegetated by a range of often dry-looking low-lying grasses, rushes and sedges. It can also be found in small patches amongst and along side mangroves and terrestrial vegetation. Depending on recent tides and rain, Coastal Saltmarsh can be inundated, have small pools of water and/or have dry patches of mudflat within it.

A prominent Coastal Saltmarsh species is Sarcocornia quinqueflora or Beaded Samphire. Saccocornia spp. is a sprawling low lying perennial herb which has decumbent stems (bending down from the tip) that are bead-like in appearance. These are predominantly light-green in colour but can also have dashes of bright pink, purple and moccasin.

Another common and also quite distinctive species found in Coastal Saltmarsh is Juncus krausii or Sea Rush. Sea Rush is a robust tussock plant which can grow to about 1.5m high. It has characteristic thin, long, green pointy stems which are very sharp in nature and painful to touch. It bears small, round red-brown flower/seed heads in large clusters of up to 50 per inflorescence.

Why is it threatened?

There are a number of factors which have significantly reduced the distribution of Coastal Saltmarsh within Pittwater and the surrounding regions. They include

• In-filling for development, including roads, residential, industrial, recreational, waste disposal and agricultural purposes.
• Modification of tidal flows as a consequence of artificial structures being erected.
• Alteration of salinity and increasing nutrient levels resulting from the discharge of stormwater into saltmarshes.
• Weed invasion, particularly by Juncus acutus.
• Physical damage from human disturbance, domestic and feral animals. Significant damage by recreational vehicles including four wheel drives, bmx and mountain bikes
• Dumping of rubbish and pollution from oil or chemical spills from shipping or road accidents; catchment runoff of nutrients and agricultural chemicals.
• Invasion by mangroves.
• Inappropriate fire regimes.

What is special about it?

Coastal Saltmarsh is rare. It occurs at only a few remaining sites within Pittwater in small and widely-scattered patches. A number of threatened plant species  grow in Coastal Saltmarsh.

They can include Distichlis distichophylla (endangered), Halosarcia pergranulata subsp. pergranulata, Wilsonia backhousei (vulnerable) and Wilsonia rotundifolia (endangered).

Coastal Saltmarsh is also important habitat for a number of threatened fauna species including the Bush Stone Curlew and important stopovers for internationally significant migratory wading birds such as the Whimbrel and Bar-tailed Godwit (listed under international conservation agreements).

Coastal Saltmarshes are also important because they fulfil a number of vital roles in coastal ecosystems. These include erosion protection, water quality improvement and habitat provision.

What animals live there?

Coastal Saltmarshes are important habitat for a diverse range of terrestrial and marine based fauna. They include crabs, molluscs, insects, spiders and birds.

A range of birds including a variety of wading birds are known to forage and roost amongst the Coastal Saltmarsh. Salt marshes can also serve as vital nurseries for important (commercial and non-commercial) fish and shellfish species that are known to utilise saltmarsh habitats during tidal flooding.

 What is Council doing to protect it?

Council is undertaking a range of projects aimed at conserving and improving the chances of survival of Coastal Saltmarsh. They include

• Weed control programs within and around Coastal Saltmarsh areas
• Management of stormwater
• Construction of walkways, boardwalks and viewing platforms around Saltmarsh areas that aim to reduce damage while allowing residents to fully appreciate these important areas.
• Removal of dumped material including garden vegetation
• Planting and transplanting of Saltmarsh species in damaged areas and allowing natural regeneration where possible
• Assisting regeneration of the riparian edge bordering Saltmarsh Areas
• Education campaign to inform residents of the importance of Coastal Saltmarsh including the field days with experts from the field, erection of educational signage and pamphlet drops to provide further information
• Council has contracted professional bush regenerators maintain and improve existing Coastal Saltmarsh stands through weed suppression, planting and general maintenance.
• Council is supporting volunteer bushcare groups with the provision of tools, removal of weeds, on-site supervision by a trained bush regenerator and employment of a professional Bushcare Program Coordinator.
• Council is also undertaking rehabilitation works in Careel Bay with $50,000 from the Hawkesbury Nepean Catchment Management Authority (HN CMA). Find out about the Coastal Saltmarsh Rehabilitation Project ...

What can you do to help protect it

• Composting your tree and lawn clippings and not dumping them on any surrounding Saltmarsh and Mangroves
• Control weed invasion on your property including Lantana, Morning Glory, Asparagus Fern and other weeds
• Minimise Human disturbance by staying on constructed access pathway and boardwalks and not walking on the Saltmarsh areas
• Join you local Bushcare group and help conserve and protect the remaining Coastal Saltmarsh. If you want further information or to join please contact the Council's Bushcare Officer on 9970 1363 or the Coastal Environment Centre on 9970 6905

Updated: 05 Dec 2011