Mangrove Walk #1

 

You can start this walk anytime between 8.30am and 10.00am. The tide will then close it until 2pm, when it will open again for 1½ hours. At 3.30pm the witch’s hats will be removed and the walk will close.


The walk starts at Morwong Beach and takes about 30 minutes. You can catch the free bus to the beach. If you'd rather walk it's an easy 15 minutes from the jetty. Just head straight up the main street and across the island, as shown in the mud map. www.cihs.org.au/map.
 

At the beach turn left and walk a short way past the picnic area to the table set up in the open green space, where this Walk#1 begins.
 

There is little shallow mud in places, and you’ll be walking on rocky rubble part of the way, so closed shoes with some ankle support are a good idea.
 

We’ve placed small witch’s hats along the walk to help you follow the route. Some of them are at points of interest – the details are in the text next to the witch’s hat symbol .  ^

The Route

1. From the start table, head towards the beach through the high grass. As soon as you step down onto the beach stop at the first witch’s hat ^ on your right.

 

The two trees with the bright green leaves, immediately next to the witch’s hat, are milky mangroves, also known as blind-your-eyes, because a toxic latex in those harmless-looking leaves can do just that. It can cause intense pain and blistering on your skin, with temporary blindness if it gets near your eyes. Thankfully it’s the only ‘look but don’t touch’ mangrove on the island.


2. Walk out onto Morwong Beach to the ^ . Stop and look straight out across the water. That’s Peel Island in the distance, and away to your right, the long low shape of Minjerribah or Stradbroke.

 

Down that far end of Morwong Beach you’ll notice a line of trees running north into the Bay along a rocky point. It’s completely submerged at high tide, so those trees have their roots in salt water for several hours every day. That  means they can only be mangroves - just a few of the 15,000 hectares of mangroves that grow in Moreton Bay.

 
3. Turn left and walk along the beach. At the next  ^ veer right, off the sand, onto the rocky rubble.

  
4. ^ This low bush is a river mangrove. If you look closely at its leaves you might be able to see the glint of salt crystals.

 

All mangroves have to remove the salt from the seawater they draw up through their roots. That’s where most of them filter it out. But the river mangrove secretes salt out onto its leaves. They’re most at home in low-salt environments, like tidal creek banks. This one is a bit out of its comfort zone.

 

Also here, just behind the river mangrove, are some stilt mangroves, with their unmistakable long curved roots that prop them up in the mud. They anchor the tree when storm tides and high winds are doing their best to rip them out of the mud in which they grow. 


5. Walk on towards the water and veer left. 


6. ^ These two big orange mangroves depend on those twisted black roots underneath them to stay upright in soft mud. They’re called ‘knee-roots’ from the shape they take as they rear up out of the ground and then dive back into the mud.

 

Trees on land can breathe with their roots beneath the soil, almost half of which is air space. But there’s no air in this mud you’re standing on, so these knee roots allow the tree to breathe, and to stay upright, when the worst storms come tearing across the Bay from Peel Island and Minjerribah.


6. Continue on to pass another ^.

 
7. At the next ^ look underneath the trees out in front of you. They're surrounded by thousands of woody fingers poking up through the mud, which identifies them as grey mangroves. The fingers let them breathe, like tiny snorkels, and they’re attached to a vast network of roots under the mud that keep these big trees anchored and upright.

 

Grey mangroves are incredible survivors, able to grow almost anywhere that mangroves can. As you travel south from Moreton Bay, mangrove species decline and by the mid-coast of New South Wales only grey mangroves remain, but they keep on keeping on all the way down to the tip of Victoria - the world’s southernmost mangroves, at Wilson’s Promontory.


8. Retrace your route to return to Morwong Beach.

 
9. When you step back onto the beach sand ^  immediately turn right to follow the narrow track into the mangroves.


10. ^ This pretty little orange mangrove is covered in the distinctive red flowers that you’ll often see on the island beaches. They fall from the tree holding ‘baby’ mangrove propagules that float away to find somewhere to grow.


11. Continue along the track to  ^ . Mangroves are amazingly protective of the tidal zones in which they grow. In January 2013, Moreton Bay was hit by destructive winds, torrential rain, and extreme storm tides.

 

Coochiemudlo’s eastern beach was severely eroded, and washed out to sea. But here, sheltered by the mangroves, their was no damage at all. The massive root systems you can see in front of you, broke up the waves, absorbing so much of their wild energy that the sand and land behind was unaffected.

 

As you walk along this peaceful sheltered path it’s worth reminding yourself that it owes its existence to the mangroves that have stood guard here for unknown thousands of years.


12. Carry on along the sand.


13. ^ Just before you leave the mangroves see how many you can identify. There are four species here: orange mangroves with knee-roots and red flowers, greys with their breathing roots poking through the mud, a river mangrove bush with salty leaves, and stilt mangroves with long curved prop roots. Can you spot them all?


14. Leave the walk by following the witch’s hats out to the concrete path. You can turn left there, to walk back to the picnic area where you started.

 
Or you can take the path to your right which leads up a short steep rise, and then out onto a sealed road, Victoria Parade West. This runs along the edge of the island’s western cliff. Stay on it for about 15 minutes, until it runs downhill, past a tree wrapped in orange plastic, where you’ll come to a concrete walking track on your left that takes you up to the community hall.