Tuesday, February 12, 2013

Wetlands, Chilika Lake & Ecosystem Health Report Card

Wetlands are those areas where water table are very near to the surface of the land and/or where land is covered by shallow water.  
Features of Wetlands:
  • Wetlands can be freshwater, brackish or salt water. It can natural or man-made. It can static or flowing. 
  • Type of wetlands - lakes, mangroves, bogs, freshwater swamps
  • 2nd Feb - World Wetland Day
  • Benefits from Wetlands:
    • food, water and fuel
    • carbon storage
    • ground water table
    • pollution control
    • protection from natural hazards - floods and storms
  • Some famous Wetland sites in India
    • Wular Lake - J&K 
    • Kolleru Lake - East Godavari - AP
    • Chilika Lake - Odisha

Ramsar Convention on Wetlands
"Ramsar Convention on Wetlands", was signed by countries in the coastal city of Ramsar, Iran in 1971. It is an intergovernmental treaty which provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources. India is signatory of this treaty.
Major obligations of countries which are party to the Convention are:
  • Designate wetlands for inclusion in the "List of Wetlands of International Importance"
  • Promote, as far as possible, "the wise use of wetlands in their territory"
  • Promote "international cooperation" especially with regard to trans-boundary wetlands, shared water systems, and shared species.
  • Create "wetland reserves"
Monreux Record 
It was created under the Ramsar Convention and is a register of wetland sites on the List of Wetlands of International Importance where some ecological degradation has occurred, occurring or are likely to occur as a result of technological developments, pollution or other human interference. This is to draw positive national and international conservation attention. Wetlands gets added to and removed from Montreux Record, based on their ecological health. 
From India, till now, three(3) wetlands have been added to Montreux Record. 
  • Chilika Lake, Odisha - added in 1993 and removed in 2002(due to excellent conservation effort)
  • Keoladeo National Park, Rajasthan - added in 1990; not removed as yet
  • Loktak Lake, Manipur - added in 1993; not removed as yet

Chilika Lake & Ecosystem Health Report Card

Chilika Lake is a salt water coastal wetland system in Odisha state. This lake is known for its rich biodiversity of bird species, has the largest Irrawaddy Dolphin population, several fish species and supports millions of fisherman in their livelihood. 

Hydrological setup of Chilika Lake

[Note: Observe the Rushikulya River/Estuary - Nesting ground for Olive Ridely Turtles. Odisha state holds 50% of world's sea turtle population and 90% of India's. It has been covered in Hindu, so better know about it .. :)]

Chilika Lake may become the first lake from Asia to adopt the “Ecosystem Health Report Card” – an effective means of tracking and reporting the health of a waterway at both local and regional scales.

Other waterbodies with such Ecological health Card are: 
  • Mississippi River, USA
  • Great Barrier Reef, Australia 
  • Chesapeake Bay, USA
  • Gulf of Mexico, Mexico

What is Ecological Health Report Card?

As you can see from the Hydrological setup of Chilika Lake in above picture, you see that several rivers are ending in Chilika Lake. These rivers carry with them several pollutants, nitrogen compounds etc. These give rise to several ecological pressure on the wetland. This health report card is a tool for managing nutrient loads into coastal waters. 

The objective of this tool inter alia is to:
  • ascertain health of the water body 
  • role of river-catchment and river nutrient and nitrogen input and its associated impact on river health - like growth of algal blooms, decrease in dissolved oxygen level etc. 
[Note: How do rivers carry nitrogen? Its because on its way it carries along animal manure, fertilisers washed away from land, domestic effluents, atmospheric deposition and soil nitrogen. These nitrogenous nutrients leads to algal blooms, which finally decreases dissolved oxygen contents in river, thereby affecting aquatic life. A question had come on this topic in CSE 2011 Prelims exams.]

This report card consists of six(6) indicators that are combined into a single overarching index of health of the water body.
  • Water Quality Index has following parameters - (1) Water Quality, (2) Chlorophyll a, (3) Dissolved Oxygen
  • Biotioc Index has following parameters - (4) Benthic Community, (5) Aquatic Grasses, (6) Phytoplankton Community 
(1) Chlorophyll a and Chlorophyll b are two pigments which impart green colour to the plan and are responsible for photosynthesis. Chlorophyll a is the most abundant pigment found in plants. Main constituent is Magnesium element(Mg). 
(2) Benthic Community - organisms that live on the bottom of the ocean floor - worms, clams, crabs, lobsters, sponges]

1 comment:

  1. Nice article....a well explored and and nicely explained


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