QUEENSLAND Monsoonal Warm and Hot Wet Summers
Mangroves in Queensland inhabit a diverse range of coastal and estuarine environments, notably present in around 18% of the 13,347 km coastline. Climatic conditions vary widely reflecting the 18 degree spread of latitude covered by the state. Regional climates are characterised by warm to hot monsoonal summers that can at times be quite dry, and sometimes very wet. The dominant feature of the north-east is the Great Barrier Reef which shelters the coast from high energy wave action. In the south-east, the coast is further protected by an extensive chain of sand islands forming extensive, sheltered coastal channels ideal for mangrove development. In the north-west, the expansive shallow gulf of the Gulf of Carpentaria provides a broad further sheltered enclave. West and east coasts are separated by an eroding mountain divide, the Great Dividing Range that diminishes north to form Cape York Peninsula with its tip in Torres Strait. Over eons, runoff to both sides of this divide has deposited silt to form extensive tidal flats at numerous river mouths, completing the setting for flourishing and extensive mangrove communities around the state.
Click on a region in the map for more detail
Highest Biodiversity in Australia
Queensland has 39 mangroves species and hybrids with nine found nowhere else in the country. All, however, occur elsewhere including the rich mangrove flora of New Guinea just across Torres Strait. In the past, these areas have been periodically united during periods of lower sea level.
Diverse climatic influences
Very wet to very dry, and tropical to subtropical climatic conditions have notably influenced species composition and structure. While there is a general decline in species numbers to the south, localised climatic factors create enclaves of highly diverse and luxuriant mangrove communities in wetter parts of an otherwise semi-arid coastline.
Highest biomass stands
Queensland mangroves have the distinction of being the most biomass rich in the country with forests to around 25 m tall, especially where lush wet tropical stands lie adjacent to the rich and luxuriant rainforests of the Wet Tropics. The northeast coast has isolated and unique, high biomass pockets of Australasian mangrove biodiversity.
- Acanthus ebracteatus subsp. ebarbatus -EG
- subsp. ebracteatus - EC
- Acanthus ilicifolius - EG,EC,CQ
- Acrostichum speciosum - EG,EC,CQ,SE
- Aegialitis annulata - EG,EC,CQ,SE
- Aegiceras corniculatum - EG,EC,CQ,SE
- Avicennia marina var. australasica - CQ,SE
- var. eucalyptifolia - EG,EC,CQ
- Barringtonia racemosa - EG,EC
- Bruguiera cylindrica - EG,EC
- Bruguiera exaristata - EG,EC,CQ
- Bruguiera gymnorhiza - EG,EC,CQ,SE
- Bruguiera parviflora - EG,EC,CQ
- Bruguiera X rhynchopetala - EC
- Bruguiera sexangula - EG,EC
- Camptostemon schultzii - EG,EC
- Ceriops australis - EG,EC,CQ,SE
- Ceriops decandra - EG,EC
- Ceriops tagal - EG,EC,CQ
- Cynometra iripa - EG,EC,CQ
- Diospyros littorea - EG,EC
- Dolichandrone spathacea - EG,EC
- Excoecaria agallocha var. agallocha - EG,EC,CQ,SE
- Heritiera littoralis - EG,EC,CQ
- Lumnitzera littorea - EG,EC
- Lumnitzera racemosa - EG,EC,CQ,SE
- Lumnitzera X rosea - EC
- Nypa fruticans - EG,EC
- Osbornia octodonta - EG,EC,CQ,SE
- Pemphis acidula - EG,EC,CQ,SE
- Rhizophora apiculata - EG,EC,CQ
- Rhizophora X lamarckii - EG,EC,CQ
- Rhizophora mucronata - EG,EC
- Rhizophora stylosa - EG,EC,CQ,SE
- Scyphiphora hydrophylacea - EG,EC,CQ,SE
- Sonneratia alba - EG,EC,CQ
- Sonneratia caseolaris - EG,EC
- Sonneratia X gulngai - EG,EC
- Sonneratia lanceolata - EC
- Xylocarpus granatum - EG,EC,CQ,SE
- Xylocarpus moluccensis - EG,EC,CQ,SE
- Sonneratia caseolaris
Legislation in place to protect mangroves and tidal wetland plants.
Increasing pressure from rapid population growth along the coastal strip.
Coordination and control of coastal development is lacking.
Mangroves occur in most coastal areas of Queensland (Ozestuaries 2006) affected by monsoonal wet summers and low waves. Four regions are based on the types of mangrove habitat determined by varying rainfall and tidal ranges, plus different geological and physiographic settings.
Eastern Gulf of Carpentaria (EG) - Dry Tropic Expansive Tidal Flats
Mornington Island to the Jardine River – 20 local catchment areas, span arid, semi-arid to humid tropical areas with micro to meso tides. The Flinders River estuary is a large arid system with around 20 mangrove species. The region has around 36 mangroves, with a total mangrove area of ~1,609 km2.
Torres and Eastern Cape York (EC) - Wet Tropic Rainforests Bordering the Great Barrier Reef
Torres Strait islands and Cape York to Hinchinbrook Island - 16 local catchment areas, span humid to very wet tropical areas with micro to meso tides. The Daintree River has 31 mangroves, making it one of the most species-rich estuaries in the world. Sonneratia caseolaris features in this region as an upriver specialist restricted to river-dominated estuaries of wetter areas. The region has all 39 Queensland mangroves, with a total mangrove area of ~1,064 km2.
Central Coast (CQ) - Catchments Big and Small to the Great Barrier Reef
Palm Islands to the Fitzroy River - 14 local catchment areas, span semi-arid to humid tropical areas with meso to macro tides. Fitzroy River is an arid region catchment, the largest in the State, with 14 mangrove species. The region has 23 mangroves, with a total mangrove area of ~895 km2.
South East (SE) - Subtropical Transition and Large Sand Islands
Curtis Island to Currumbin Creek on the Gold Coast - 16 local catchment areas, span humid subtropical areas with meso tides. Brisbane River in Moreton Bay includes 6 species, although just two dominate, namely Avicennia marina generally, and Aegiceras corniculatum in upstream reaches. The region has 14 mangroves, with a total mangrove area of ~533 km2.
In 1997, a severe hail storm killed nearly 200 hectares of mangroves in southern Moreton Bay, and the effects are clearly evident nearly a decade later.Queensland mangroves have always been affected by adverse natural climatic conditions that are manifest seasonally and annually in the first instance, and episodically with severe events. Various natural factors pose significant threats. Changing rainfall conditions result in expansion or contraction of mangrove areas depending on fluctuations in rainfall. Physical damage to foliage and stems is caused by severe wind and hail storms. Sea level rise results in zonal shift that replaces upland vegetation. Other influencing factors include: increased sea surface temperatures and decreased coastal frosts; insect infestations like caterpillar plagues result in significant defoliation inhibiting mangrove growth and survival; storm-wash wrack smothers breathing roots and trees die; and, erosion destabilizing trees and redeposition of fine sediments buries breathing roots to suffocate trees.
Urban expansion accounts for large losses in mangrove area throughout Queensland, but especially along the south east coast.Queensland has the fastest growing population in Australia with a 2% increase between 2004 and 2005 alone. Queensland also has the greatest area of mangroves inhabiting the greatest number of estuaries, far exceeding all other States. The environmental changes and instability created by such massive population increases are ever-present, and these threaten mangrove areas throughout the state. This is exacerbated by newly arriving people attracted to places inhabited by mangroves, especially to estuaries. Natural habitat loss and altered land use feature prominently as severe threats to wetland habitats and mangroves. Specific manifestations of human impacts, include: vast areas lost to landfill with the construction of coastal cities; canal estates, marinas, ports, airports and industry increased direct damage with greater access and trampling; more frequent boat wash; plus, degradation caused by pollution from oil spills and agricultural chemicals
Community conservation & education
Public interest for preserving, protecting and monitoring mangroves is high in Queensland. This is mostly evident by the number of dedicated volunteers who work with environment groups in most coastal centres of the state. Public interest in mangroves is reflected further by the number of mangrove boardwalks. For example, in SE Queensland, there are around 25. Additional boardwalks have been constructed in more remote northern areas, including Hinchinbrook Island, Cairns, and the Daintree. Most include educational signage describing mangrove features, functions and values. There is no coordinated strategy for community engagement for monitoring of mangrove health and condition in Queensland. However, such ideas are on the agenda, and community members are keen to make a start. The recently released Community Monitoring Methods for Marine Environments developed by the DPI&F (Department of Primary Industries and Fisheries), DNRM&W (Department of Natural Resources, Mines and Water), EPA (Environmental Protection Agency) and Waterwatch Queensland, was funded by the NHT (Natural Heritage Trust) Coasts and Clean Seas program. However, there is no indication of community uptake and application of this manual for mangrove monitoring. The community requires the further assistance of a specialist group to train volunteers, receive data, synthesis observations, report results and disseminate information. Research on mangroves in Queensland, for the most part, is uncoordinated and ad hoc, depending on the success of individual researchers in getting funding, and postgraduate university student projects. Mangroves are studied therefore without consideration of overall or agreed priorities, or without identification of key current and developing issues affecting the States’ valuable tidal wetland habitat.
In 1967, Harrison published a first concern about mangroves, specifically regards their loss in Queensland due to coastal development. Since then, numerous management actions have been implemented, including:- protection of mangroves, along with other marine plants, in Queensland under the Fisheries Act 1994, resting with DPI&F; additional regulatory and protective legislation concerning mangroves with the EPA State and Regional Coastal Management Plans, Environmental Protection Act 1994, Integrated Planning Act 1997, Wild Rivers Act 2005, and Local Government Strategic Plans; further encompassing legislation helps protect mangrove habitats with the Marine Parks Act 1982, National Parks and Wildlife Act 1975, Nature Conservation Act 1992, Great Barrier Reef Marine Park Act 1975 and the Environment Protection and Biodiversity Conservation Act 1999. Responsible regulatory agencies include DPI&F, EPA, DNRM&W, the DLGP (Department of Local Government, Planning, Sport and Recreation), plus local shire and city governments. While no formal state-wide coordination of estuarine management exists for protection of tidal wetland habitat in Queensland, the role is spread amongst multiple agencies with overlapping and incomplete jurisdictional responsibilities.