Why we should love the Redlands' mudflats

Many Redland residents know that the early explorer Matthew Flinders landed on Coochiemudlo Island. Locals and visitors alike are soon to celebrate this occasion. But fewer know that amongst Matthew Flinders notes are references to the vast mangrove forests which first greeted the early European explorers. So extensive were the mangroves that they obscured the mouth of the Brisbane River.

Moreton Bay-Quandamooka has a line of islands to the east, forming its seaward boundary. Extending from the Sunshine to the Gold Coasts the relatively shallow expanse of water is where the tropical and temperate waters meet, mingled with freshwater flows from six rivers and a number of creeks.
Its unique geography has led to the formation of diverse habitats – coral reefs, rocky, sandy and muddy foreshores – which in turn provide feeding and breeding grounds for thousands of species, some endemic.

Moreton Bay facts

Moreton Bay:

• has the highest recorded diversity and abundance of resident and transient whales and dolphins in Australia
• is the only place in the world where dugongs are found this close to a capital city
• supports six of the world’s seven sea turtle species and many shark and ray species
• annually attracts 32 species of migratory birds which join the resident bird populations
• has thousands of species of fish, molluscs and other invertebrates
• is an important  recreation space for the people of SEQ

The Moreton Bay Marine Park was declared in 1993. Due to the environmental significance of these wetlands Moreton Bay-Quandamooka is a Ramsar site. These declarations and agreements are intended to guide our actions and to ensure survival of the bay’s biodiversity. But will it be enough?

The mudflats exposed at low tide are exceptionally rich with myriad life – small worms, crabs and molluscs – an integral part of the food chain. They are not a barren, under-utilised wasteland waiting to be ‘reclaimed’ as some would have us believe.
Mangrove wetlands and seagrass beds possess an extraordinary number of stunningly beautiful animals, each playing an important role in the healthy functioning of the marine environment. Yet to some, they are merely murky, smelling, temporary impediments to development approvals. That this is the attitude of many who wield considerable power in land use planning and decision-making is perturbing.

Citizen scientists get muddy

Counter to this, over the past year close to 100 Citizen Scientists, several being Redland residents have volunteered nearly 1,000 hours to the collection of data on seagrass and mangroves in Moreton Bay, its rivers and creeks.
Some may ask why seagrasses and mangroves are important, what’s driving these people to give up their time, to get onboard vessels or to slosh around in mud? The reasons are as varied as the participants themselves but a focus on seagrass and mangrove monitoring is due to these species being the ‘coastal canaries’ – they provide early signs of changes in the quality of marine environment.
The ecosystem services provided by seagrass include:

• buffering and filtering nutrients and chemical inputs
• stabilising coastal sediments
• providing food and shelter for many organisms including two iconic species, dugong and green turtle
• being nursery grounds for commercially important prawn and fish species
• storing carbon 35 times faster than rainforests
• locking carbon in for thousands of years

Despite these significant benefits 50% of Australia’s seagrasses have been destroyed by dredging and pollution. Resistance to the loss of seagrasses is strengthened by knowing that when it is exposed to the air, the sediment beneath seagrass releases greenhouse gases which compounds rising temperatures.
Similarly, mangroves are early detectors of change while providing multiple ecosystem services from which we all benefit. The mangroves are:

• filtering coastal pollutants
• trapping sediments which is protecting coral reefs
• essential habitat for species, including ‘our seafood’
• providing visual amenity and recreational opportunities
• highly effective and cost efficient carbon sequesters – locking 1,000 tons per hectare of carbon in their soils (more than three times as effective as tropical forests)
• protecting shorelines and valuable coastal real estate from erosion and storm surge (30 mangroves per 100 square metres in villages on India’s east coast reduced the maximum flow of the 2004 tsunami by more than 90 percent)
• a cost-effective alternative to built infrastructure for shoreline defence

Mangroves, and their companion habitat tidal saltmarshes, are amongst the most endangered marine wetland habitats. Worldwide they are disappearing at up to two per cent a year on average.
The “Wild Guide to Moreton Bay” published by the Queensland Museum states:

It is vital that we all make the connection between the loss of bushland at the end of the street, the filling of wetlands or the channelisation of creeks, and the effect that this might eventually have on the health of the Bay. Each small act may seem insignificant in its own right; however when multiplied together they have a considerable impact.

The Minister for the Environment, Hon Greg Hunt MP will be pivotal in the fate of Moreton Bay-Quandamooka given that the Toondah Harbour proposal will require his Federal Governmental approval.
On 16th July the Minister is hosting the Threatened Species Summit which is claimed “will reinforce the new national focus on threatened species”. Will the appointment of a Threatened Species Commissioner, the adoption of his “Threatened Species Strategy” and a policy framework with measurable targets help the threatened and vulnerable species of Moreton Bay-Quandamooka? Time will tell and Toondah Harbour will be the test.

Lets hear it for mud!

Mud be in it
Mangroves love it
Seagrass grows in it
Insects and fish breed in it
Birds and crabs feed in it
And we should look after it.
Mudflat Arts

References and other reading

Peter Davie and others, Qld Museum. Wild Guide to Moreton Bay.
AMCS. Moreton Bay Marine Park.
Department National Parks, Recreation, Sports & Racing. Managing Threatened Species in the Moreton Bay Marine Park
National Parks et el. Moreton Bay Marine Park User Guide.
Asean Centre for Biodiversity. Mangroves, our insurance against the wrath of nature.
SEQ Catchments. The SEQ Ecosystems Services Framework
MangroveWatch
Wildlife Queensland Coastal Citizen Science

Toondah Harbour marina a Federal matter

 Debra Henry

Project Officer, Moreton Bay
Wildlife Queensland Coastal Citizen Science
Conducting Seagrass-Watch and MangroveWatch in Moreton Bay
The views expressed are those of the author and not necessarily those of WPSQ.