Monday, November 26, 2012

Historical State of the Mangroves

The history of the Sundurbans can be found all the way back to 200-300 c.e. A city built by Chand Sadagar has been found in the Baghmara Forest Block and during the Mughal Empire Raja Rai took refuge in the Sundarbans from the advancing armies of Emperor Akbar. During the Mughal period of 1203-1538, the local kings leased the forests out. It became the first mangrove forest under scientific management. In 1764 the Surveyer General mapped out the area. The Mughal Emperor Alamgir II gave away the proprietary rights to the East India Company in 1757. In 1869 they started the systematic management of the forest after the Forest Management Division in the Province of Bengal in British India. The Sundurbans were officially declared a reserved forest in 1875-76. The forest act was established in 1865. The Forest Act was established in 1865. A forest division was created in 1879. The Forest Division headquarters is located in Khulna. The reserved forest stretched from 266 from the mouth of Hugli to the mouth of Meghna. It was bordered inland by 3 districts. The three districts were the Parganas, Khulna and Backergunj. (http://www.portal.gsi.gov.in/portal/page?_pageid=127,723772&_dad=portal&_schema=PORTAL&linkId=1213, 2012)

Citation:
"Geological Survey of India." Geological Survey of. Government of India , n.d. Web. 1 Dec. 2012. <"http://www.portal.gsi.gov.in/portal/page?_pageid=127,723772&_dad=portal&_schema=PORTAL&linkId=1213">

Past and Present

This was a sketch done by Frederick Peter Layard in 1839. This sketch shows a village that is in the Sundurbans in Bangladesh. 



"This image was created by merging Landsat 7 satellite observations from Novemeber 24,1999, and November 17 and 26, 2000." (http://earthobservatory.nasa.gov/IOTD/view.php?id=7028, 2000) This image shows the Sundurban forests which are a deep green. The agricultural lands are the lighter green. The shrimp farms are near the edge of the protected area which raises some concern because it may be detrimental to the ecosystem. 

Citation:
1. Layard, Frederic . Village in a clearing, Sundarbans. N.d. British Library Online Gallery, Bangladesh. British Library. Web. 26 Nov. 2012.
2. Satellite, Landsat 7. Sundurbans. 1999. NASA, Bangladesh and Southwestern India. Earth Observatory. Web. 26 Nov. 2012.

What are the Sundarban Mangroves exactly?

There are 3 wildlife sanctuaries that are on the islands close to the borders of India. They are called Sundarbans East, West and South. "The sanctuaries are intersected by a complex network of tidal waterways, mud flats and small islands of salt tolerant mangrove forests. The area is flooded with brackish water during high tides which mix with freshwater from inland rivers." (http://whc.unesco.org/en/list/798, 2012)  Mangrove forests are special because they have to have a broad range of salinity, which limits the amount of species that can live in a Mangrove forest. The forests transfer organic matter to the water which provides nutrients for marine animals. "They provide critical habitat for numerous species of fishes and crustaceans that are adapted to live, reproduce, and spend their juvenile lives among the tangled mass of roots, known as pneumatophores, that grow upward from the anaerobic mud to get the trees' supply of oxygen." (http://www.eoearth.org/article/Sundarbans_mangroves, 2008). Mangrove forests create a complex system of ecosystems. 
Citation: 
1."The Sundarbans - UNESCO World Heritage Centre." UNESCO World Heritage Centre. UNESCO, n.d. Web. 26 Nov. 2012. <http://whc.unesco.org/en/list/798>.
2. World Wildlife Fund (Lead Author);Mark McGinley (Topic Editor) "Sundarbans mangroves". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth September 3, 2008; Last revised Date July 4, 2012; Retrieved November 22, 2012 <http://www.eoearth.org/article/Sundarbans_mangroves>

Current Human Impacts on the Mangroves




This picture shows how the land filled with mangroves
has been cleared for farming purposes.
(http://www.flickr.com/photos/ipsnews/8033144559/)
     There are various impacts that humans give to the Mangroves. These impacts not only apply to the Sundarban Mangroves but the Mangroves around the world. One human impact is agriculture. There are many cases relating to the conversion of major mangrove sites as agriculture spots. “It is said that in one of the biggest delta regions in the world, about 150,000 ha of mangroves were destroyed in 100 years” (http://ocw.unu.edu/international-network-on-water-environment-and-health/unu-inweh-course-1-mangroves/Degradation-and-destruction-of-mangroves.pdf). Turning such areas into agricultural lands occur when enough salt is dissolved in the ground. These mangrove lands are often used to grow paddies or coconuts. Even though much about the relationships between mangroves and other wetlands and species are not accurately known, mangroves habitat is a famous nursery areas for many species which are seeking for shelter. Loss of such area endangers many growing species, which in return hurt the community around the mangroves like a chain rule. (http://www.worldchanging.com/archives/001835.html)



This picture shows the result of aquaculture in Cirebon, West Java.
Farmers are not willing to go into stormy weathers.
(http://www.thejakartapost.com/news/2012/02/16/mangrove-damage-worsens-cirebon.html)
     
     Another example of current human impacts on the mangroves would be urbanization. This impact spreads as the human population starts to grow and the mangrove sites are destroyed for human inhabitation. Such example is true because “the human population in the Sundarbans, now estimated at more than 2 million, continues to increase very rapidly” (http://www.eoearth.org/article/Sundarbans_mangroves).  Urbanization leads to other various human impacts such as timber and aquaculture practices. mangroves can be cleared for timber, which can be used to produce energy sources. Because of the nature of their wood, mangroves are used for construction purposes. This therefore leads mangroves as a famous timber source. Also, aquaculture can greatly impact mangroves. The main reason why aquaculture destroys mangrove population is due to acidification of the water. Considering that mangroves depend on water, building aquaculture altered the chemistry and the nature of the water which in return has declined the mangrove habitats. (http://www.eoearth.org/article/Sundarbans_mangroves)


Citation:

Kathiresan, K. "Threats to Mangroves." OCW. N.p., n.d. Web. 30 Nov. 2012. <http://ocw.unu.edu/international-network-on-water-environment-and-health/unu-inweh-course-1-mangroves/Degradation-and-destruction-of-mangroves.pdf>.

Fund, World Wildlife. "Sundarbans Mangroves." Sundarbans Mangroves. Encyclopedia of Earth, 03 Sept. 2008. Web. 30 Nov. 2012. <http://www.eoearth.org/article/Sundarbans_mangroves>.