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The importance of the mangrove ecosystem

The importance of the mangrove ecosystem

July 25, 2022

It is hard to think of an ecosystem type that covers less of the earth’s surface whilst playing a more important role than that of mangroves.

This stilted maze of greenery found in intertidal zones along the coast does more than provide a home for crabs, with key functions in biodiversity and climate mitigation also being part of its repertoire.

Today is a great chance to talk about them too: it’s the International Day for the Conservation of the Mangrove Ecosystem.


WHAT IS THE INTERNATIONAL DAY FOR THE CONSERVATION OF THE MANGROVE ECOSYSTEM?

This convoluted title is essentially a marker for a calendar event highlighting the importance of mangroves. Though most of us have come across them before, and many will have seen them, far fewer understand their importance to the planet.

As with many ecosystems around the world, they are facing a number of challenges - and this affects us all.

In 2015, the UN Educational, Scientific and Cultural Organisation (UNESCO) agreed that July 26 each year would be a day to celebrate these diverse, widespread and fragile habitats. But why?


THE IMPORTANCE OF MANGROVES

Mangroves contribute to both the wider environment and human society in a number of ways.

They offer protection to coastal communities, give food security and help dissipate the energy of waves. Critically, they are also highly effective as carbon sinks - sequestering vast amounts of carbon as a natural process - and are home to an incredibly rich array of species, from fish and crustaceans to birds and mammals.

Nestled where land meets sea, mangroves are extraordinary ecosystems full of biodiversity. They withstand high saline levels, tidal floods, limited oxygen supply and more. The sad part is, they are disappearing up to five times faster than total forest loss globally, and over the past 40 years it is estimated that mangrove coverage has halved.

“Mangroves are in danger,” says Audrey Azoulay, UNESCO Director-General. “It is estimated that more than three quarters of mangroves in the world are now threatened and with them all the fine balances that depend on them.”



MANGROVES IN AUSTRALIA

Australia holds the third largest area of mangroves in the world, and those found in Victoria’s Gippsland are recognised as the planet’s most southerly growing mangroves. We harbour 41 different species of the plant, which is more than half of the world’s known types.

These biomes are found in every Australian mainland State as well as the Northern Territory, and Traditional Owners have many uses for them including as an important food source for fruit, crabs and fish, and for timber used in the construction of canoes and weapons.

Despite this relative abundance and importance, the total area of mangrove coverage here is less than one million hectares. That’s only around 0.6% of Australia’s native forest cover (DAFF, 2022).

These numbers become even more surprising when you consider the many lifeforms that depend on these unique biomes; monitors, crocodiles and snakes all shelter in these tangled roots in the north and, when the tide is out, cassowaries can be seen weaving their way through the maze.

Further south the mangroves are no less important, being home to many smaller bird species and numerous mammals including dolphins and dugongs.

As with much of our environment, however, external pressures are increasing.


CONSERVATION OF MANGROVES

A few years ago, researchers from James Cook University in the Northern Territory found that a combination of heatwaves, rising sea levels and cyclones in consecutive years had destroyed some 400km of mangroves in the Gulf of Carpentaria. This is one of many signs of the stress these ecosystems find themselves under.

But it is critical that mangroves, as with all natural ecosystems, are preserved. According to UNESCO, just one hectare of mangrove forest can store almost 4,000 tonnes of carbon - much like removing 3,000 cars from the road for a year.

And the flip side to this fantastic carbon sequestration ability is that, when destroyed, that same ecosystem becomes a release point for large amounts of carbon dioxide. Despite mangroves covering 0.7% of land, they account for some 10% of emissions resulting from deforestation.


OUR WORK FOR ECOSYSTEM REGENERATION

The Foundation works to protect not only wildlife, but the habitats upon which they depend.

A number of our projects are focussed on rewilding regions, rather than conserving one species, and these efforts are becoming increasingly important.

Learn more, and see how you can help, on our Projects page here.