Wetlands

Wetlands are just that – areas of land that are regularly wet. They are inundated by water on a regular or semi-regular basis. The animals and plants that live in wetlands have adapted to the cycle of wet and dry conditions. Wetlands can be natural or constructed.

Habitats include:

Intertidal wetlands

• marine wetlands – sandy and rocky shores
• estuarine wetlands – sandbanks and mudflats, mangroves, salt marshes and swamp oak woodlands.

Non-tidal wetlands

• vegetated wetlands – tree, heath, grass, sedge and herb.

Wetlands are critical natural assets. They provide benefits and services to us just like assets or infrastructure that we build. They:

• protect city infrastructure such as homes and roads from the impacts of waves, flooding and erosion
• contribute to climate change mitigation and adaption – wetlands cover just 9% of the planet's land surface, yet are estimated to store 35% of land-based carbon (source: Ramsar scientific and technical review panel)
• absorb pollutants and improve water quality
• are some of our most popular places for recreation including fishing, walking, kayaking and boating.

Internationally significant

One of our most significant wetlands is in the Coombabah Lakelands Conservation Area. This wetland is the most southerly lake and coastal swamp system in the South East Queensland bioregion. The conservation area provides significant wildlife value and refuge habitat. It forms part of the Moreton Bay Marine Park which is listed as a wetland of international significance under the Ramsar Convention. Moreton Bay is one of only 4 wetlands in Queensland that is internationally recognised.

Marine (intertidal) wetlands

Marine wetlands are intertidal areas along our coastline. They are within and adjacent to marine waters which are exposed at low tide and covered at high tide.

Sand beaches

Sandy shores are the most common type of marine intertidal wetland on the Gold Coast. They occur along most of our 52 kilometres of coastline.

Rocky shores

Marine tidal areas in rocky areas occur predominantly at headlands, including constructed rock walls. Natural rocky shores occur at North Burleigh Headland, Burleigh Headland, Currumbin Rocks, Elephant Rock, Flat Rock, Kirra Point, Greenmount Headland, Snapper Rocks and Point Danger.

Importance

• Natural assets – protect coastal areas from wave action, storms, and coastal erosion
• Provide habitat for:
  - resident and migratory shorebirds which forage for invertebrates such as crabs, marine worms and molluscs
  - the eastern beach of South Stradbroke Island is a confirmed nesting location for green and loggerhead turtles
  - Little Terns breed on the open sand at the top of South Stradbroke
  - Pied oystercatchers forage for shellfish on rocky and sandy shores.

Estuarine (intertidal) wetlands

Estuarine wetlands fringe our coastal waterways and cover mud islands in open estuaries. They are a mosaic of treed and treeless areas. Estuarine wetlands can be very changeable in size and area due to the influence of tides and floods. Different types often occur together depending on the level of tidal inundation.

It is estimated that before European settlement, more than 11,000 hectares (approximately 8%) of Gold Coast land was estuarine wetlands. Some have been cleared for the development of marinas, homes and other coastal infrastructure. It is estimated that more than 75% of these wetlands have been retained since European settlement.

Estuarine wetlands include:

• Sandbanks and mudflats – areas exposed at low tide
• Mangroves – mangrove forests fringe our coastal waterways and cover mud islands in our open estuaries. Salt water inundates these areas during every high tide. You can see them along the boardwalk at Paradise Point, Currumbin, Jabiru Island, Macintosh Island and the Southport Broadwater Parklands. Find out more about mangroves:
  Mangroves of the Gold Coast(PDF, 764KB)
  Living with mangrove odours(PDF, 748KB)
• Salt marshes – occur at the outer or higher marine intertidal zone and are usually slightly more elevated than adjoining mangroves. They are typically inundated by salt water only at the very top of high tides. They are dominated by low-growing, saltwater tolerant plants such as marine grasses, sedges and samphires (succulent, herbaceous plants that grow in high-salinity environments).
• Swamp oak woodlands – occur at the upper limit of the tidal zone, in areas infrequently inundated by saltwater on spring tides. They are dominated by swamp oak. Isolated tall trees, mostly forest red gum, sometime extend out above the canopy.

Importance

• Natural assets – estuarian wetlands reduce the impacts of floods, absorb pollutants, and improve water quality. Known as the 'kidneys of our coast', mangroves have an important role cycling nutrients within our coastal environment.
• Recreation – bird watching, kayaking/paddling
• Commercial fishing – up to two thirds of fish caught off the Australian coastline spend some of their lifecycle in tidal wetlands and estuaries. The structural complexity of mangroves – thick sticky mud, tangled roots and aerial roots – shelters important nursery habitat for many animals in our coastal environment including fish, prawn and crab species that are harvested commercially.
• Habitat – as the boundary between terrestrial and marine environments, estuarine wetlands are strategic refuge areas, supporting plants found nowhere else. They are home to many species of migratory and resident shore birds and provide nursery and breeding areas for a large range of animals including fish, birds and invertebrates.
• Rare, threatened, and notable plants and animals include:
  - trees – more than 6 species of mangrove, coastal vitex, swamp oak
  - shrubs – ruby, grey and berry salt bush, mangrove boobialla
  - ground covers – swamp club rush, sea rush, beaded samphire, marine cooch
  - priority species for conservation – water mouse
  - resident shore birds – beach stone-curlew, red-capped plover
  - migratory shorebirds – eastern curlew, bar-tailed godwit, whimbrel, curlew sand piper, ruddy turnstone.

Vegetated wetlands

Vegetated wetlands occur in low-lying areas which are periodically waterlogged or subject to water inundation. Plants are adapted to low oxygen soil environments and prolonged periods of inundation They are a mosaic of different types which are characterised by different wetland plants including trees, heaths, grasses, sedges and herbs.

It is estimated that before European settlement, more than 19,000 hectares (approximately 15%) of our city's land was vegetated wetlands. These areas have been extensively cleared and modified by the construction of the canal system and draining of the flood plains. It is estimated that less than 10% of those vegetated wetlands now remain. The remaining vegetated wetlands are of high ecological and economic value.

Local vegetated wetlands:

• Melaleuca wetlands – on the Gold Coast, paperbarks (Melaleuca species) are the dominant species in tree wetlands but small numbers of other tree species such as Queensland Blue Gum or Swamp Oak may also occur.
• Heath wetlands – occur on the coastal plain. Wildflower and low shrubs such as dwarf banksia, tea trees and swamp grasstree are dominant, as well as rushes and swam ferns. They predominantly have low-nutrient soils deficient in phosphorus and nitrogen. Heath wetlands can be seen together with wallum heathlands in Pine Ridge Conservation Park.
• Grass, sedge and herb wetlands – occur in low-lying areas that are frequently water logged. Plants are aquatic and semi-aquatic, including rushes and sedges. These wetlands occur in the Conservation Park on South Stradbroke Island.

Importance

• Reduce the impacts of floods, absorb pollutants, and improve water quality
• Climate change mitigation and adaption – store carbon and help us adapt to climate change
• Tourism and recreation – sensitive ecotourism opportunities exist to view these unique ecosystems
• Habitat – support a rich and unique diversity of plant and animal species which have adaptations and behavioural traits that have evolved to meet the demands of a challenging and difficult environment
• Rare, threatened, and notable plants and animals include:
  - trees – broad leaved paperbark, cabbage palm
  - shrubs – safrole boronia, wallum hakea, White's tea tree
  - ground covers – swamp orchid, Christmas bells, leafy twigrush, love creeper, shiny bog-rush, tall saw-sedge
  - priority species for conservation – water mouse, swamp crayfish, wallum froglet
  - water birds including – black-necked stork, Australian painted snipe.