Mangroves And The Shaping Of Guyana's Coast

Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

MANGROVES COASTLINE

AND THE SHAPING OF GUYANA'S - R SEECHARRAN MSc(Eng), CEng, REng, IFPO

Everyone living along the coastal strip of Guyana has come into contact with, or at least heard of, the "Courida Bush", but to what extent this ubiquitous plant has shaped our coastline, and ultimately our lives, we seldom pause to contemplate. It is hoped that this discourse will stimulate thought, bring about awareness, and eventually lead to measures aimed at its conservation.

Mangrove areas in Guyana The mangrove is the characteristic tree of the coastal mud flats and marshlands of Guyana. Worldwide, mangroves cover about one percent of the world's total area and they are renowned as the plants that reclaim land from the sea. In Guyana's case, mangroves have been building up our coastal strip utilising Amazonian silt brought to our shores by the Guiana current, an offshoot of the south equatorial current. Mangroves are almost as quick to take root and grow in the silt deposited by rivers and oceans, as those sources are efficient in providing the silt to grow on. Over geological time, this process of land reclamation has bequeathed Guyana with this rich, alluvial mud flat on which we coastal inhabitants thrive.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Atlantic Ocean currents showing the currents which carried Amazonian silt to form coastal Guyana It is generally agreed that the earliest mangrove species originated in the Indo-Malayan region. This may account for the fact that there are far more mangrove species present in this region than anywhere else. Because of their unique floating propagules and seeds, some of the early mangrove species rode the ocean currents to spread westwards to India and East Africa and eastwards to the Americas, arriving in Central and South America between 66 and 23 million years ago. During this time, there was an open seaway between North and South America. As a result, mangroves spread throughout to the Caribbean Sea. Later still, sea currents may have carried mangrove seeds to the west coast of Africa, which at that time, was much closer to South America as the Atlantic was opening. This explains why there are so few similar species colonising West Africa and the Americas, whereas those of Asia and East Africa contain a much fuller range of species. Rhizophora propagules, Seawell Village, Berbice Guyana The complex many-tangled root system of the mangrove help silt to settle, and once it has done so, keep it trapped. When mangroves have taken hold on a large scale, a rising of the land level follows as more and more silt is laid down.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Eventually, what was a shallow, underwater or tidal mud flat becomes solid ground. All mangrove species are able, through one form or another of specialised roots, to secure and maintain a firm foothold in the soft mud. All of them, too, will tolerate, to greater or lesser degrees, both salt and fresh water. This adaptation serves them well since most mangrove swamps are flooded twice daily by the tides. Some mangrove trees reach imposing heights of up to 30 metres; others are low and shrub-like. All are evergreen species, most bedecked with shiny leaves and small flowers. Mangrove species often create new land by taking root in the mud of the seashore and establishing a forward wall of plants that trap debris and silt. The pioneer genus RHIZOPHORA (Figure 1), takes hold just above the level of the lowest of the low tides. It can withstand almost continuous flooding because its roots are particularly tolerant to salt water. As the land begins to build, RHIZOPHORA is replaced by AVICENNIA. The roots of this genus (Figure 2), are lapped regularly by the various tides, but they too can tolerate high dosages of salt water. LAGUNCULARIA flourishes higher on the new land bank, its more sensitive roots washed only twice a month by the highest of all tides - the spring tide. Since one of the functions of tree roots is "breathing", to take in oxygen and get rid of carbon dioxide, mangroves are faced with a problem in the oxygen deficient environment of mud and tidal water in which they live. This dilemma they have successfully solved by root adaptation. The root systems are generally of three types. In the most spectacular form, the trunk sends many roots like flying buttresses into the mud creating an impenetrable tangle (Figure 1). Another sends its roots out horizontally, and every so often each root makes a sharp U-bend straight upward and downward again, resembling a knee protruding above the water in a bathtub (Figure 3).

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

MANGROVES ROOT SYSTEM A third type, instead of looping up and down, simply sends a protuberance, likened to a stubby branch, up into the air (Figure 2). In all three cases the aerial portions supply oxygen for the rest of the root system, and as the land level rises, these unique adaptations send out new growth while the older roots are gradually stifled and used as a binder for the loose silt below. Mangrove trees have seeds that are specially adapted for a muddy environment. One characteristic is that they germinate before they leave the parent tree; so that when they hit the soft silt they are already seedlings set to take immediate advantage of it, putting out their own roots and starting to grow. They are heavy, fleshy and often shaped like plumb-bobs, so when they fall into the mud they penetrate it deeply, planting themselves. These germinating seeds are also capable of surviving considerable water voyages in case they are floated away by tide or current. Because of the way in which they propagate themselves, each new generation is planted about half a tree width further into the water. In some areas, mangroves grow in such profusion that they are almost impenetrable but there are also great stretches where they will grow only sparsely. The reason for this disparity lies not just in conditions at the seashores but in the composition of the great inland mountain ranges hundreds, or even thousands, of kilometres away. If the mountains are granite, which disintegrates into fertile mud on the long journey to the sea, mangrove jungles are almost certain to be found on the coast. If those mountains are sandstone, the infertile silt deposited at the shore will not support thriving mangrove colonies. Almost all mangrove forests around the world are Government owned and harvesting needs special permission. Economic use of mangrove forests is greatest in South Asia. The National Mangrove Committee (NATMANCOM) has been established in Asia to advise governments in the planning and implementation of technical projects, and to determine the existing problems on utilisation and conservation of mangrove resources. In the Sundarbans in India, management of the mangrove forest has been in practice for the past 100 years. Currently, it allows five percent of the forest to be harvested every year. Under this system, small patches are auctioned off so that all members of the community can participate, and at the same time, keep the commercial operators out. All trees above a pre-determined diameter are cut as long as their felling does not create a permanent gap in the canopy. Under this system of rotation, each section of the forest is harvested once in every 20 years. Mangrove soils reclaimed as sediments from the sea contain a high proportion of iron sulphides in the form of FeS and FeS2. This comes about when the sulphate in sea water is reduced by bacterial action and precipitated out as sulphide.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

As the mangrove soils are drained for agriculture and the construction of harbours, or fisheries ponds and canals are excavated, the exposure of the sulphide sediments to air results in their oxidation and the eventual formation of sulphuric acid thereby increasing the acidity of the soil. This acid formation is detrimental to both plant and animal life.

Mangrove Fauna

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Laguncularia on Crab Island in Berbice, Guyana

Mangrove Flora

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

The causes of mangrove destruction around the world are many:         

Overexploitation by traditional users Conversion of the forested area to aquaculture Conversion of the forested area to agriculture Conversion of the forested area to salt pans Conversion of the forested area to urban development sites Construction of harbours and canals through the forested area Use of the forested area for the mining of minerals Use of the forested area for solid and liquid waste disposal Spillage of oils and other hazardous chemicals

Mangroves protecting Guyana’s sea defence

Mangrove degradation in Nigeria, caused by oil pollution Mangrove forests are an essential part of the Guyanese ecosystem. In addition to providing fuel wood and building material, they act as the nursery and feeding areas of many fish, crab and shrimp species. In some countries, mangrove bark is used in the tanning of leather. The flowers of mangroves produce excellent honey, as is seen in the Sundarbans of India and Bangladesh. With rising sea levels, these mangroves become essential as Guyana's first line of defence against inundation by the sea. In Indonesia, significant steps have been taken to conserve the dwindling mangrove resource.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Harvesters must leave an undisturbed protection zone 100 times wider than the tidal range along the seaward margin and 50 metres wide along the rivers. In the Cayman Islands the study of mangroves has been incorporated into the school curriculum. Since so much of our existence in Guyana depends on this unique, well-adapted species, should we not spare a thought for this natural marvel and endeavour to protect it so that it can in turn protect us.

Ramoutar Seecharran ENVIRONMENTAL CONSULTANT

APPENDICES I)     

SOME MEASURES BEING TAKEN GLOBALLY TO CONSERVE MANGROVE SPECIES

Involvement of local communities in sustainably managing and protecting their coastal resource base. Lobbying multilateral lending agencies to stop funding aquaculture/agriculture development, which involves the cutting down of mangroves. Educating consumers in developed countries to reduce their demand for pondraised prawns and shrimps. Encouraging education authorities to include the study of mangroves and its ecosystem in schools curricula. Enforced legislation.

Mangrove degradation in Guyana

Mangrove in the province of West Papua in Indonesia, near the town of Timika

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

II)

SUNDARBANS, WEST BENGAL and BANGLADESH

I’ve spent many hours studying the Sundarbans, concentrating on the West Bengal branch. This section covers about 40% of the total area, the other 60% being in Bangladesh. Where the land meets the sea at the southern tip of West Bengal lies the Indian Sundarbans, a stretch of impenetrable mangrove forest of great size and bio-diversity. A UNESCO World Heritage Site (awarded in 1997), the Sundarbans is a vast area covering 4262 square kms in India alone, with a larger portion in Bangladesh. 2585 sq. kms of the Indian Sundarbans forms the largest Tiger Reserve and National Park in India, habitat of the majestic Bengal tiger, endemic to this specific area. The total area of the Indian part of the Sundarbans forest, lying between the latitudes 21°13’ to 22°40’ north and longitudes 88°05’ to 89°06’ East, and is about 4,262 sq km in area, of which 2,125 sq km is occupied by mangrove forest.

Mangroves of the Sundarbans in West Bengal, India The Sundarbans are a part of the world's largest delta formed by three major Asian rivers Ganges, Brahmaputra and Meghna. Situated on the lower end of the Gangetic Plain, it is also the world’s largest estuarine forest. The Sundarbans is renowned as being inhospitable, dangerous and monotonous. Dense mangrove forests occupy the 56 islands and the remainder of the area is under saline water which flows through numerous tidal channels and creeks. It is difficult to approach and even more difficult to spend time in this swampy area, but for those who dare, it is one of the most attractive and alluring places remaining on earth. My childhood spent growing up in East Berbice in Guyana prepared me well for the Sundarbans experiences. Living among the fishermen, beekeepers and charcoal burners is a rewarding experience. These impoverished people have so little, yet they give so much. A family does not eat until the guest has been fed on the crudely made chapati, dhal and kitcheree cooked in a clay stove (chhula) with mangrove wood as fuel.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Cooking kitcheree for the evening meal in the Sundarbans on the ubiquitous clay stove (Chhula). Fuel wood was mangroves Although I cannot speak Bengali, we were able to communicate by sign language and I was accepted as the long lost Indian son who had returned to these shores! As I carried out my studies and photography, the local people could not fathom why an educated man came from the UK to live and study such primitive conditions in his global peregrinations. My being there was the discussion of most household evening cogitations around the ubiquitous mangrove fires. In my after dinner ruminations and discussions, I’ve tried to stress the importance of sustainability and the impending effects of rising sea level on the livelihood of these remarkable people.

The magestic majestic Bengal tiger of the Sundarbans, this species is endemic to this part of the world

Mrs. Yayati strikes a glamorous pose in the Sundarbans outside of her house, made from mangrove poles

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

The mudskipper of the Sundarbans, the cousin of Guyana’s “four-eyed” fish My recent arduous mining assignments in Africa have meant a long sojourn from my beloved Sundarbans and I look forward to the day when I can resume my studies there. I hope by the time I return, I would not detect any major environmental degradations.

The author at the entrance to the Sundarbans on a hot and humid premonsoon night in May 2009, equipped with traditional Bengali garland (mala) and cameras

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

I know the government of West Bengal is keen in preserving the unique ecosystem of the Sundarbans and the livelihood of its inhabitants; they have “preserved forestry” legislation in force.

A boy poses with his fishing seine in the Sundarbans

Mrs. Chakrabharty catches fish with her fishing seine in the Sundarbans in West Bengal

Mrs. Mukherjee proudly exhibits her evening’s catch for the outside world to see……. …….sustainability is essential for survival in the Sundarbans, this is testimony of that! In Bangladesh, this story is well known, and is the inspiration of people who depend on the Sundarbans for their livelihood.

On November 7th 1990, Koronamoyee Sardar was killed by an armed gang of hired thugs. The businessman’s aim was to set up a shrimp farm at Horinkhola Polder 22. The local villagers, led by Koronamoyee, resisted this invasive force.

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

On that fateful day, Koronamoyee became a martyr for her cause, and in the eyes of her people she remains their heroine in their decade long ongoing struggle against the surrounding oppressors. The supreme sacrifice of Koronamoyee is not forgotten. Every year, on November 7th, there is a great celebration at Polder 22, where thousands of resisters peacefully gather to commemorate this brave woman who led a successful movement of the people against a powerful, unscrupulous industry. Today, Horinkhola Polder 22 is the only remaining shrimp farmfree village in the shrimp farming district of Khulna. A great battle was won,……………but the war continues.

VICTORY TO THE MANGROVES…..AND ITS PEOPLES!!!!

Mrs. Mishra, her daughter Deepali and grandson Ramakant go about their daily duties in the Sundarbans, inure of the business taking place in congress in Delhi, they have lived their entire lives here and know no other lifestyle

The Bhattarcharjee kids pose for a wide angle shot, unaware of the effect rising sea level can have on their homeland, the Sundarbans

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Kids going to school in the Sundarbans

A fiddler crab in the Sundarbans

Mangrove swamps of Mumbai. Without mangroves, India’s commercial capital will be inundated by the sea at high tide

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Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

The author studying mangroves in the Maldives in 2014

Mangrove estuary in the Maldives

Mangrove root system building up land above water level (Maldives Islands) 15

Mangroves and the shaping of Guyana’s coastline By Ramoutar Seecharran

Mangroves are intolerant to pollution which stunts its growth and leads to its extinction. Countries like Guyana, Nigeria, Bangladesh and India should learn from this salient and scientific fact

Only mangroves can rescue island communities like The Maldives, Vanuatu and Kiribati from inundation by the sea due to rising sea level

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