Sargasso sea an unique geography

Sargasso sea :--
--------------------

 Sargasso sea is located in the north Atlantic ocean north of Bermuda. It's is the only sea bounded not by land but by oceanic current . The North Atlantic gyre holds the water. It obtained the name from Portuguese word sagassum which means a seaweed. Sargassum is a brown algae which is free floating like a plankton River.

 It is confined between 20N -35N degree and 30W-70W degree. It is bounded by north equatorial current in the south, Antilles current in south west, gulf stream in west, north atlantic in the north, Canary current in the east direction. Sargasso sea is characterised by depth 1500m-7000m, still water, saline, evaporation rates >> precipitation rates, horse latitude belt, sargassum seaweed covers 2million square km area in the sea.

 Marine biologist declared sargossa sea as biological desert because of lack of nutrients, devoid of plankton in large part of it, absence of large fish. High salinity of Sargasso sea due to lack of oceanic water mixing, high temperature (26) and higher evaporation rates. But known for small marine lifeforms such as turtles,shrimp,crab, small size fishes, eels lay eggs,etc these animals has unique adaptation to high sea weed(Sargassum). Which is not available anywhere on earth.

It has great economic value as mention above. The resource is used by carribean nations such as Bermuda, Antilles islands. This region is highly vulnerable to pollution, oil spills, etc,.

Measures adopted to conserve and protect the Sargossa sea unique ecosystem. Since 2005, IUCN consider this region under loss of biodiversity because it falls away from the national jurisdiction boundary. Few agreement reached are :-

1) Hamilton declaration in 2014 signed by 5 nations.

2) Bermuda alliance for Sargasso sea.

3)  mission blue

4) Sargasso sea alliance.

Aral sea shrinking

Aral sea shrinking

---------------------------
Aral sea was the 4th largest lake(68000 sq km area) since 1960, more than 90% water is being lost. It shrink in size,  broken down into two parts. It arise due to :-
1) diversion of two Rivers that feed it such as syr-darya and amur-darya for irrigation purpose during the USSR times for cotton fields.
2) daming of Rivers by Kyrgistan, Tajikistan,
3) encroachment of lakes by Uzbekistan and Kazakhstan.
4) climate change and global warming leads to desertification,here due to dry climate water is lost more per year.
5) long period of continuous droght in the central Asia.
6) first time it's Eastern basin is completely dried in 600 years.
7) in 1960s, Soviet to make vast steppes bloom. They built an enormous irrigation network more than 20,000 miles of canals, 45 dams and more than 80 reservoirs , all to irrigate fields of cotton and wheat in Kazakhstan and Uzbekistan.

Impacts of Aral sea drying is :-
 1) waterbody become more saline, in saltier sea million of fishes died.
2)by 20009 lake is separated into the north (small) Aral sea in Kazakhstan and the south (large) Aral sea in Uzbekistan.
3) the south Aral sea further splits into western and Eastern lobes. In 2009, eastern lobe dried up but rebounded after more rain.
4) salinity increased in the field, crops in the region are destroyed, to flux out excess salts from field water is used many times.
5) desertification of the region, ecosystem collapse, river deltas feeding into it have been destroyed, dust storms are frequent leads to winters colder and summer hotter.
6) receding of coastlines, left large plains covered with salts, toxic chemicals from weapon testing, industrial and agriculture waste.
7) land around the Aral sea is heavily polluted, causing health problems to local people , there longevity falls, mortality increases,
8)fishing industry collapse, coast become the ship graveyards.

Solution and measures :-
1) alternative farming system such as less water intensive cotton varieties, avoid chemicals, shift to other crops, micro-irrigation
2) promoting non agricultural development in upstream countries.
3) plantation of area to increase rain and check duststorms
4) quality of irrigation canals need to be improved.
5) redirecting waters From other Rivera of Russia to restore Aral sea within 20-30 years. From river Volga, Ob, Irtysh and Caspian sea.
6) in 1994, all 5 central Asian countries signed a deal to recover the sea by allocating 1%of their budget for it's conservation .Aral sea basin programme was adopted in 1994 .
7) in 2006, world bank restoration project especially in the north Aral sea.