A Queenslander, Carole King beat 600 international entrants, with a collage picture of mangroves. As well as being beautiful, this art work educates the viewer about the scientific importance of mangroves, and subtly highlights the danger that human intervention presents for these delicate ecosystems. (www.abc.net.au)
The mangroves at our respite centre at Laguna Quays near the Whitsundays in Queensland remind me of the wonder I felt as a child when I noticed that the mangrove trees grew differently from those in the paddocks on our farm. I used to be amazed also at the variety of wildlife (including the insects!!!! )
Australia has 11,000 square kilometres of mangrove forests stretching all the way around the vast coastline (except in Tasmania) – and the vegetation in the cold waters of Victoria is quite different from that in the temperate climate. There are more than 40 different plant species, and I would not recognise some of these as being anything like the mangroves of my youth in the tropics. (www.kidcyber.com.au)
What are mangroves?
Genesis 1 verse 20 (KJV) "And God said, Let the waters bring forth abundantly the moving creatures that hath life, and fowl that may fly above the earth in the open firmament of heaven."
And that is exactly what can be observed in the mangroves, which are all part of the "intertidal zone" where the salt water from the sea washes up onto the land. Although the trees and sea-grasses and orchids and lilies and other understory plants may look different in various climatic zones, they all thrive on periodic flooding and drying with the tides.
The bigger trees have huge root systems to enable them to withstand this constant ebbing and flowing, and they actually slow the movement of water. This moderates damage that might otherwise be done by high tides and major storms, and encourages more sediment to be deposited (sand and nutrient-bearing muds). The integrity of the coastal habitat on the inland side is therefore naturally protected by the mangroves.
Their extensive and integrated plant communities and tangled roots enable the mangroves to build their own unique environments. For example, they filter out some of the salt; they don't actually use the salty water in their growth, but purified fresh water like other plants. (en.wikipedia.org)
Mangroves can come right up to the road
Importance of mangrove ecosystems
Mangroves are also ideal habitats for a wide range of animals and birds. They are extremely important sheltered breeding grounds for a range of fish and crustaceans, including many commercial species such as barramundi and prawns (in the areas where they are naturally found).
Land animals, too find shelter and food among the tangled undergrowth and roots of mangroves; lizards certain snakes, flying foxes, and other mammals as well as many insects and the birds and frogs that feed on them.
The leaf litter and other debris naturally formed by the plants breaks down very quickly in the sheltered, moist environment. Naturally occurring micro-organisms use this as a food source, and in turn their waste provides excellent nutrition for the animals that live there. Amazingly, these nutrients also wash into the ocean with every tide, providing food for small shellfish, plankton and creatures far out to sea.
Mangroves can become endangered
Because Australians are concentrated around the coastline, and the most prestigious places to live are by the beach, many of our mangroves have already been cleared or the land reclaimed. There is no "going back to nature" in these cases, we can only create artificial systems to mimic the original mangrove protection zone, as described in my recent article on sand reclamation near Laguna Quays. (christiantoday.com.au)
Even where the mangroves are healthy, Professor Pauline Ross of the University of Western Sydney has found in her research that consistent trampling, say on a walking path, can destroy some of the tiny understory plants, and the animals and shellfish that use the environment near that pathway.
There is a growing awareness of the importance of mangroves to the environment, the economy and our overall health. Nowadays, many of the remaining mangrove forests are protected under conservation policies of the various states. There are also grass-roots activities (excuse the Dad-pun) where people can get involved in helping to preserve what we can of our various mangrove forests. If you are interested, there are links at: www.mangrovewatch.org.au
Usually I am inspired by nature to make a painting; this time, the painting inspired me to brush up on some environmental science!
The O'Connell River 30 min south of Proserpine mangroves go wild in the wet season
Dr Mark Tronson is a Baptist minister (retired) who served as the Australian cricket team chaplain for 17 years (2000 ret) and established Life After Cricket in 2001. He was recognised by the Olympic Ministry Medal in 2009 presented by Carl Lewis Olympian of the Century. He mentors young writers and has written 24 books, and enjoys writing. He is married to Delma, with four adult children and grand-children.
Mark Tronson's archive of articles can be viewed at www.pressserviceinternational.org/mark-tronson.html