May 19, 2012

A Paper on Mangroves


Mangroves lie perpetually in the limbo between the sea and fresh water. They thrive in an environment that would kill and ordinary plant within hours. They are the epitome of tough, through and through. Yet, within what seems to be an extremely harsh environment, there is a delicate balance of life, and the diversity of this habitat knows no bounds. However, mangroves are under grave threat from human activity, and if we do not act now to protect them, than we will lose an incredibly useful and beautiful asset. 

What are mangroves?

The term “mangroves” applies to a small number of plants-from the smallest shrubs to the biggest trees-that are able to withstand the anoxic and extremely saline conditions of the river-ocean boundary. “Mangrove forests” or “mangrove swamps” applies to large congregations of these plants. Due to the harsh conditions that they must tolerate, the number of species that fall into this category is small; only around 100 species are present in this group. 

Mangrove forests grow in the brackish waters of river-ocean boundaries, but may also be found along coasts. Their roots spread far and wide and help to stabilize the soil. They are mostly found in Asia, but are also found in North America and as far south as New Zealand. Mangroves provide important economical benefits to local communities, and have been depended on by people for thousands of years. Mangroves share a symbiotic relationship with another important habitat-coral reefs. The reefs prevent the coastal land where the mangroves grow from eroding away, and the mangroves trap silt and toxins that would smother and kill the coral.

Unique Adaptations

It is obvious that no ordinary plant can tolerate the conditions that mangroves have to on a daily basis. Therefore, the plants of the mangrove forest have evolved many special adaptations to help them survive. 

One of these adaptations is the presence of pneumatophores in the plant’s root system. Pneumatophores act as snorkels, and take in nitrogen, oxygen and other gases that the plant needs to survive. The reason why it needs this is due to the fact that the mud that the plants grow in is waterlogged most of the time, and because of this the plant cannot get the gases it needs. Having pneumatophores solves this problem and allows the plant to receive the necessary gases from the air. Another adaptation is the use of salt glands. Like the name suggest, these filter out excess salt from the water that the mangrove absorbs, and prevents it from getting into the tree. Due to the nature of their job, they are often seen covered in salt crystals.

In order to reproduce effectively, mangrove seeds germinate when attached to the parent tree. They then drop off, and float on the water until they find a suitable habitat to grow in. When they find their new home, they change their density and plant themselves in the soil. The amazing thing is that they can survive complete desiccation and revert back to normal if their ideal habitat doesn’t support them anymore.


What life can be found there?

The animals, birds and insects that call the mangroves their home are a large and diverse group. Most of the wildlife there is the larvae and young of any fish, insects, reptiles and crustaceans. The quiet habitat offered by the twisting maze of the mangrove’s roots is a perfect place to grow up in. Largely free of the threat of predators, and with ample food and hiding places, the young offspring of countless species live in the mangroves until they reach adulthood. Then, they venture out to open ocean or swampy land to live out the rest of their lives.

This is not to say that all residents of the mangroves are temporary. Tarpon, snook, snappers, jacks and trout all live permanently in the submerged tangle of roots typical of a mangrove forest. Sea turtles, horseshoe crabs and flamingos can be found in the shallows.  Egrets, cormorants, proboscis monkeys and ospreys are just some of the inhabitants of the canopy. Crocodiles, mudskippers and swamp wallabies are all found in the swamps and mudflats. 

The most common creatures in the mangroves are insects. Hundreds of species can be found anywhere in the mangrove forests, from the inundated roots to the muddy swamps. Mangroves are not a breeding ground for mosquitos. This is an urban legend. Mangroves do, however, house many other insects, such as mangrove spiders, stinging caterpillars, bees, praying mantises, crickets and leaf miners.



What are the uses of mangroves?

People have been depending on mangroves for thousands of years. They are a versatile resource that fits almost any role. Much of what we harvested from mangroves centuries ago is still being harvested today. For example, commercial exploitation of mangroves for charcoal has been going on in Malaysia since the 1800’s. 

Red mangrove wood has a very high calorific value, and thus can produce effective and long lasting charcoal. Mangrove forests are also a rich habitat for exotic fish and exploitation, for both sport and food, is one of the most popular uses of mangroves. Village communities living in and around that the forests have used extracts from them as herbal remedies for everything, from asthma to cancer to rashes. The wood proves an effective material to build jetties with, as it resists rot and attack by fungi and borers. Houses and thatches can also made from mangrove wood. Tea and alcoholic beverages can be brewed from the leaves of mangrove plants. When used conservatively, the forests can be used as a natural sewage treatment plant, as they filter out toxins and organic waste.

The economic value of mangroves mainly comes from tourism, but can also come from fishing and the export of raw materials. Mangroves are an unusual habitat, and as such many people will pay to visit them. When managed properly, tourism can be an effective way to promote awareness. The revenue can also be used to fund ecological projects, and keep the mangroves in good health. Therefore, tourism is an effective way to mesh profit and conservations together. An added benefit is that people will be made aware of this precious habitat, and what can be done to protect it.

Another economic use of mangroves is to use them sustainably as fish farms. The yield will be small, but the income can be used to revitalize or create local “small job” economies. In order to make sure that the forests remain protected, the local people can be employed as rangers, further increasing the economic value of this versatile habitat. An effective strategy is to pay local communities for their fish, and in turn they receive education on sustainable fishing methods, environmental awareness and how to maximize profit while minimizing the environmental cost.

In conclusion, mangroves are a treasure trove of potential. The economic and environmental benefits to be gained are immense. However, any activity within the mangroves must remain supervised. If the activity, be it tourism or fishing or farming, is not supervised, then poachers or careless visitors could permanently damage the forests.

What are the threats that mangroves face?

Perhaps the biggest threat to mangroves is the razing of them for aquaculture-farming shrimp to feed an insatiable global appetite. Almost no one has ever heard of a mangrove forest, so when reports come in about the destruction of this beautiful habitat, many don’t seem to care. Some of those who are aware of mangroves see them as an ugly blight on the coast that must be removed, or as a breeding ground for mosquitos. Due to these inaccurate beliefs, mangrove forests are being destroyed at an alarming rate. So, what can be does to stop this mindless destruction? The reality isn’t actually as bleak as it sounds. More and more people are becoming aware of the importance of mangroves, and several important steps have been taken towards the conservation of this critically important habitat.  However, much more still remains to be done.
In order to protect mangroves, one must understand what makes this habitat “tick”. To live in a mangrove forest, a plant or an animal must be extraordinarily tough in order to withstand the harsh conditions. Therefore, mangroves are quite capable of tolerating man-made conditions that would destroy other habitats, but only up to a certain point. The Achilles’ heel of mangroves is chemical pollution. Mangroves located near sewage treatment plants have been reported as biological dead zones, completely devoid of life.  In conclusion, mangroves are tough, but they will need our help to survive.
One way of doing this is to maintain more sanitary shrimp farms. The geological location in which mangroves thrive is perfect for shrimp farming. If you encounter a patch of mangrove near a developed coastline, you will almost certainly find a shrimp farm. The shrimp in these farms are left to live in their own excrement, and as such, more and more antibiotics are required to keep them healthy. The chemicals, combined with the excrement, are released in a toxic, mangrove killing wave when the pond becomes little more than a noxious soup. More farms are then begun elsewhere, repeating the process.  In order to prevent this, the ponds must be kept clean, just as you would clean an ordinary aquarium. Doing this increases the life expectancy of the shrimp, the surrounding mangroves, and the facility itself.
Another way of protecting mangroves is to avoid building any chemical/sewage treatment plants anywhere in the vicinity of a mangrove forest. Doing so would mean instant death for whatever lived there. The chemicals that we use to dispose of our waste and manufacture synthetic products are incredibly toxic to mangroves and the animals within them. If you must build them, build them where they will not cause the destruction of an entire habitat.
Probably the most effective way of protecting mangroves is to raise awareness about them. If people know about the threats faced by this ecosystem and have the drive to do something about it, than that can make all the difference in the world. Educate your neighborhood. Start an action group.  Participate in mangrove related activities. There are a million possibilities.
Conclusion           
Mangroves are one of the most important ecosystems on the planet. Humanity has depended on them for thousands of years. However, not many people realize their importance, and as such, they are not receiving the protection that they deserve.  We must take action, raise awareness and stop the mindless destruction of mangroves. Otherwise, we will lose an asset that cannot be replaced and humanity’s future will be severely impacted.