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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.