Which Indian lake is reported to contain about 20 percent of the country s total seagrass distribution within its lagoon ecosystem?

Introduction / Context:
Seagrass meadows are underwater flowering plants that play a crucial role in coastal ecosystems by stabilising sediments, providing habitat for marine species and storing carbon. In India, seagrasses are found mainly along the coasts and in certain lagoons, and some protected areas are recognised for having a large share of the country s seagrass distribution. This question asks which lake or lagoon contains about 20 percent of India s seagrass, linking physical geography with marine ecology and conservation.

Given Data / Assumptions:

- The focus is on seagrass distribution in India. span style="display:block;">- The lake in question is said to possess about 20 percent of India s seagrass area. - Options include Chilika Lake, Kolleru Lake, Dal Lake and Wular Lake. - Only one of these is a coastal brackish water lagoon known for seagrass meadows.

Concept / Approach:
Seagrasses require shallow coastal or lagoon waters with suitable salinity and light penetration. Chilika Lake in Odisha is a large brackish water lagoon connected to the Bay of Bengal and is well known for its rich biodiversity, including seagrass meadows that support fish, crabs and migratory birds. Studies and conservation reports often state that Chilika accounts for a significant proportion of India s seagrass distribution. In contrast, Kolleru is a freshwater lake, and Dal and Wular are freshwater lakes in the Kashmir region, where marine seagrass does not occur in the same way. Therefore, the approach is to recognise that Chilika is the only coastal lagoon among the options and is accordingly associated with seagrass.

Step-by-Step Solution:

Verification / Alternative check:
Verification can be done by reviewing environmental reports and conservation documents about Chilika Lake. These often mention that the lagoon supports extensive seagrass beds and attribute a substantial proportion of India s total seagrass area to Chilika. By contrast, descriptions of Kolleru, Dal and Wular focus on freshwater fish, migratory birds and wetland characteristics, without highlighting seagrass meadows. This difference in ecological features confirms that Chilika Lake is the lake referred to in the question.

Why Other Options Are Wrong:
Kolleru Lake is primarily a freshwater lake subject to seasonal changes, and while it is important for birds and fish, it is not known for large marine seagrass meadows. Dal Lake and Wular Lake, located in the Kashmir Valley, are freshwater lakes in a temperate climate and do not provide typical seagrass habitat. None of these lakes fits the description of containing 20 percent of India s seagrass distribution, which is tied to a coastal lagoon like Chilika.

Common Pitfalls:
Some students may be tempted to choose Kolleru simply because it lies near the coast in Andhra Pradesh or because they associate it with biodiversity. Others may pick Dal or Wular due to their fame in tourism without considering the ecological conditions required for seagrass. To avoid such mistakes, it is important to connect seagrass specifically with shallow coastal and lagoon environments, and to remember that Chilika Lake in Odisha is the key Indian example for seagrass based questions.

Final Answer:
The lake that is reported to contain about 20 percent of India s seagrass distribution in its lagoon ecosystem is Chilika Lake in Odisha.