Download - Mangroves of The Gold Cost
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Why are mangroves important?Mangroves are an extremely important habitat within our
coastal environment. They have been called the kidneysof our coast, because of the role that they play in
nutrient cycling within the coastal environment. Many of
the animals that live in mangrovessuch as crabsfeed
on detritus (dead or decaying matter). This returns the
nutrients to a form that organisms higher in the food
chainsuch as fish or humans can use.
The structural complexity of mangroves (think sticky
mud, tangled roots and pneumatophores) shelters
important nursery habitat for many animals in our coastal
environment, including some fish, prawn and crab
species that are harvested commercially. In fact, up to 70
per cent of the seafood that we eat is dependent on the
mangrove environment for at least part of its lifecycle.1
Mangroves also play a valuable role in foreshore
protection. Their extensive root systems assist in
maintaining shoreline stability. During storms, mangrove
forests can reduce the rate of erosion and the impact of
storm waves and surge by absorbing wave energy.
Mangroves of theGold Coast
What are mangroves?A mangrove is a plant that grows above the average mean sea level of an intertidal zone (between low and high
tide). True mangroves have special adaptations that help them live in salty and oxygen-deficient soils. For example,
their aerial (above-ground) roots, called pneumatophores, help them to breathe, see Figure 1. These specialised
structures are filled with spongy tissue and numerous holes that maximise oxygen absorption, acting almost like
snorkels. Mangroves are also able to desalinate the nutrients that they take in from the environment around them.
Cell membranes at the root surface act as a barrier to salt, and any salt that is taken in can be excreted through the
leaves.1Look closely and you will see salt crystals on their leaves.
Mangrove forests fringe our coastal waterways and cover the mud islands in our open estuaries. You cansee them along the boardwalk at Paradise Point, Currumbin, Jabiru Island, Macintosh Island, and the
Southport Broadwater Parklands.
Wherewill
mangrovestakeyou?
Enjoytheswampyhabitats
withastrollalongour
Citysboardwalks.
Mangrove forests often smell
a bit like rotten eggs.
This pungent smell isnot a health risk
nor is it related to
pollution ormosquito
breeding.
The smell is, in fact, a sign of ahealthy mangrove forest as it signifies
that leaf litter is being effectively
recycled into the complex food web.
Healthy Habitat
Smelly Swamp
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Example of a Greg Mangrove. Do you see the
pneumatophores that carpet the sand?
1 Duke, N. (2006)Australias Mangroves: The Authoritative Guide
to Australias Mangrove Plants,University of Queensland, St. Lucia,
Brisbane.2 Lovelock, C. (1993) Field Guide to the Mangroves of Queensland,
Australian Institute of Marine Science.3 Davie, P. (1998) Wild Guide to Moreton Bay, Queensland
Museum, Brisbane.
Typesof mangrovesyoujustmightseeontheGoldCoast
The Grey Mangrove (Avicenna marina) is common to the Gold Coast and features smooth bark and leaves that
are light green on top and silvery-grey underneath.1Their most noticeable feature is the mass of pneumatophores
that surrounds them, which look like pegs reaching out from the mud.1You will find Greg Mangroves fringed along
most of Gold Coasts waterways.
The Red Mangrove (Rhizophora stylosa) features a distinctive root system of arching stilt or prop roots that are
long, above-ground extensions reaching from the main trunk and anchoring the mangrove into the mud.1These stilt
roots also have breathing cells to draw in air.1The leaves of the Red Mangrove occur in clumps at the end of the
brachlets and feature numerous brown spots on the underside.1 You can spot Red Mangroves amongst the many
mangrove forests on the Gold Coast, e.g. Paradise Point or Currumbin.
The River Mangrove (Aegiceras corniculatum) with its small oval leaves, features an adaptation to this salty
environment with small salt glands on the underside of each leaf.1If you turn the leaf over and look closely, small,
conspicuous crystals of salt can be seen.1Adding to the scents of the mangrove forest, the bundles of small, white
flowers smell like rotten bananas.3You can see River Mangroves at Currumbin.
The Orange Mangrove (Bruguiera gymnorrhiza) features large, glossy leaves (up to 20cm long) occurring in
clumps at the end of the branches.1The bark of this mangrove is rough and fissured and characteristic knee roots
branch from the lower level of the truck into the mud like bent knees.1Flowers of the Orange Mangrove are red and
cup-shaped with green, cigar-shaped propagules or seeds extending from the flowers.1You can see Orange
Mangroves along the boardwalk at Paradise Point.
MangrovesareprotectedCoastal development, pollution and climate change
place immense pressures on our beautiful
mangrove forests. In the past, extensive
mangrove forests throughout Queensland havebeen cleared for development, which has lead to
a loss of habitat and increased the risk of
storm-related inundation. Today, mangroves are
now protected and any disturbances, no matter how
small, require a Queensland Government permit
under the Fisheries Act 1994.
Looking after our mangrovesClimate change will place increasing pressure on
mangrove forests on the Gold Coast in the future. It is
important that we manage this impact, and ensure that
any impacts of adjacent urban development are
minimised. Today, mangroves are protected under the
Queensland Fisheries Act 1994 and any disturbance to
mangroves requires a permit issued by the Department
of Environment and Resource Management.
The Gold Coast City Councils waterways maintenance
program includes weekly litter collection. Also, as partof the city-wide Nature Conservation Strategy, Council
is conducting an assessment of the coastal environment
to formally identify and map coastal ecosystems.
Assessing and monitoring the health of our citys
mangroves will be a part of this process.
What can you do? Use environmentally friendly detergents
Dispose of oil wastes at appropriate depots, e.g.
landfills
Pick up litter and dispose of fishing debris
appropriately
The CoastEd program provides free education sessions
about mangroves for people in the community keen to
learn more.