Correct Option
The correct option is D. 3 only
[as per provisional answerkey]
Explanation
Mangroves are specialized halophytic (salt-tolerant) forest ecosystems found in tropical and subtropical intertidal regions. They serve as a critical interface between terrestrial and marine environments, providing essential ecosystem services related to climate adaptation and coastal protection.
- Statement 1 is Incorrect: While mangroves do reduce tidal energy, they do not store freshwater in a manner that facilitates paddy cultivation. Mangrove soils are typically anaerobic, saline, and acidic (acid sulfate soils). Converting mangrove belts into paddy fields requires extensive drainage and desalination, which destroys the ecosystem and is not a rationale for their protection.
- Statement 2 is Incorrect: Mangroves are salt-tolerant, not salt-sensitive. They possess specialized mechanisms such as salt-excreting glands or ultra-filtration at the root level to exclude salt. They do not convert coastal land into freshwater zones; rather, they maintain the brackish water equilibrium. Promoting freshwater aquaculture in these zones often leads to the destruction of mangrove biodiversity.
- Statement 3 is Correct: Mangroves act as "bio-shields" by dissipating the energy of storm surges, cyclones, and tsunamis through their complex aerial root systems (pneumatophores and prop roots). Furthermore, they support rural livelihoods by providing biomass, timber, medicinal plants, and acting as nurseries for commercial fish and shell-fish species.
Key Takeaway
The primary rationale for mangrove conservation lies in their role as natural physical barriers (bio-shields) against coastal hazards and their high carbon sequestration potential, rather than their conversion for terrestrial agriculture or freshwater use.