Pretty in pink, but Malarikkal’s lilies worry ecologists

Environment & Ecology · 17 October 2026 · Based on The Hindu (original report)

Worth reading — 1 past UPSC question on this theme (Prelims GS-1 2023); also a live issue with two sides, good for Mains.

2-minute summary

A two-year study commissioned by the Kerala State Biodiversity Board (KSBB) has raised ecological concerns over the uncontrolled growth of pink water lilies (*Nymphaea*) in Malarikkal, located in Kottayam district, Kerala. Proliferating rapidly following the severe 2018 Kerala floods, the lilies have created a major three-month seasonal tourism hotspot starting every July. This seasonal floral bloom generates significant local revenue for farmers, boat operators, and tour service providers. However, ecologists and biodiversity experts warn that the dense weed cover impedes water flow, restricts sunlight penetration to deeper aquatic layers, and displaces native aquatic plant species. Furthermore, experts have expressed alarm over localized methane emissions generated by the anaerobic decay of massive plant biomass during the post-bloom die-off phase. The situation underscores a critical governance challenge in balancing eco-tourism-driven rural economic development with long-term aquatic ecosystem restoration and biodiversity management.

Why it's in the news

A two-year study conducted for the Kerala State Biodiversity Board (KSBB) highlighted severe ecological impacts—including sunlight blockage, native flora displacement, and potential methane emissions—caused by uncontrolled pink water lily growth in Malarikkal, Kottayam.

Facts to remember

  • Malarikkal is located in the Kottayam district of Kerala, famous for seasonal water lily blooms.
  • The rapid proliferation of water lilies in Malarikkal was triggered following the 2018 Kerala floods.
  • The Kerala State Biodiversity Board (KSBB) is a statutory body constituted under Section 22 of the Biological Diversity Act, 2002.
  • Decaying aquatic plant biomass in stagnant water environments undergoes anaerobic decomposition, leading to localized methane emissions.
  • The Biological Diversity Act, 2002 establishes a statutory three-tier governance framework: National Biodiversity Authority (NBA), State Biodiversity Boards (SBBs), and local Biodiversity Management Committees (BMCs).

Background and context

Extreme climatic events such as extreme rainfall and flooding frequently alter hydrology and soil nutrient dynamics, facilitating the sudden dominance of opportunistic aquatic species. In wetland systems like Kerala's Kuttanad and adjoining backwater regions, post-flood silt deposition creates nutrient-rich conditions conducive to dense floral growth, such as water lilies (*Nymphaea*) and water hyacinths (*Eichhornia crassipes*). While vibrant floral displays often attract eco-tourism—providing supplemental income during lean agricultural months—uncontrolled vegetative cover severely disrupts the aquatic web. It starves sub-surface layers of photosynthetic active radiation (PAR), depletes dissolved oxygen (DO), and degrades benthic habitats. Furthermore, mass die-offs of unharvested biomass convert carbon sinks into net sources of greenhouse gases, particularly methane ($CH_4$). Managing such ecosystem shifts requires institutional coordination between local panchayats, State Biodiversity Boards (SBBs), and Irrigation Departments under the statutory framework of the Biological Diversity Act, 2002.

Constitutional provisions

  • Article 48A — Directive Principle directing the State to protect and improve the environment and safeguard water bodies, forests, and wildlife.
  • Article 51A(g) — Fundamental Duty of every citizen to protect and improve the natural environment, including lakes, rivers, and wildlife.

Committees and reports

  • Kerala State Biodiversity Board (KSBB) Malarikkal Study — Assessed the ecological impacts of uncontrolled water lily growth post-2018 floods on local aquatic species, hydrology, and GHG emissions.

Government schemes

  • Biological Diversity Act, 2002 — Provides the legal framework for biodiversity conservation, sustainable use, and establishment of SBBs and BMCs.

International organisations

  • Convention on Biological Diversity (CBD) — International treaty signed at the 1992 Rio Earth Summit; India enacted the Biological Diversity Act, 2002 to fulfill its CBD commitments.

Previous UPSC questions on this theme

  • Prelims GS-1 2023 — Consider the following statements : 1. In India, the Biodiversity Management Committees are key to the realization of the objectives of the Nagoya Protocol. 2. The Biodiversity Management Committees have important functions in determining access and benefit sharing, including the power to levy collection fees on the access of biological resources within its jurisdiction. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

Mains practice: Uncontrolled growth of aquatic flora after extreme weather events often leads to severe ecological degradation while creating short-term rural livelihoods. Discuss the socio-ecological trade-offs involved and suggest management strategies under the Biological Diversity Act, 2002.

The proliferation of floral species post-disaster—such as the rapid growth of pink water lilies in Malarikkal (Kottayam) following the 2018 Kerala floods—highlights the operational conflict between short-term eco-tourism income and long-term wetland integrity.

• Ecological Impacts vs Economic Benefits:

- Ecological Degradation: Dense aquatic weed canopies block photosynthetic active radiation, leading to severe drop in Dissolved Oxygen (DO) levels. Mass decomposition of plant biomass under anaerobic conditions generates methane ($CH_4$) emissions, converting wetlands into local carbon sources.

- Socio-Economic Gains: The 3-month seasonal bloom (July–September) creates vital supplementary livelihoods for local boatmen, homestay owners, and small vendors, creating local resistance to eradication measures.

• Institutional & Statutory Framework:

- Statutory Mandate: Under Section 22 of the Biological Diversity Act, 2002, State Biodiversity Boards (SBBs) are tasked with advising state governments on conservation and sustainable resource use.

- Implementation Deficit: Local Biodiversity Management Committees (BMCs) set up under Section 41 of the Act often lack technical tools, dedicated funding, and regulatory capacity to enforce sustainable carrying-capacity norms for eco-tourism.

Way Forward:

• Integrated Biomass Harvesting: Mandate phased physical removal of weeds before the decay phase to prevent anaerobic decomposition and methane release.

• Circular Bio-Economy: Promote processing of harvested floral biomass into bio-fertilisers, animal feed, or natural fiber handicrafts, preserving rural livelihoods beyond tourism.

• Regulatory Carrying Capacity: Enforce eco-tourism regulations through BMCs under Article 243G powers, setting strict visitor limits in ecologically fragile backwater zones.

Conclusion:

Balancing ecological preservation with community livelihoods is vital to fulfilling Article 48A and achieving SDG 15 (Life on Land), ensuring that nature-based tourism does not compromise wetland ecosystems.

Prelims practice questions

Q1. Consider the following statements regarding biodiversity governance in India: 1. State Biodiversity Boards (SBBs) are executive bodies established directly under Article 252 of the Constitution of India. 2. Biodiversity Management Committees (BMCs) are set up exclusively at the Union level under the direct control of the Ministry of Agriculture and Farmers Welfare. 3. The Biological Diversity Act, 2002 completely prohibits eco-tourism activities across all aquatic wetland ecosystems in India. How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None

Answer: D. Statement 1 is incorrect: SBBs are statutory bodies established under Section 22 of the Biological Diversity Act, 2002, not constitutional bodies under Article 252. Statement 2 is incorrect: BMCs are constituted by local bodies (Panchayats/Municipalities) at the local level under Section 41 of the Biological Diversity Act, 2002 under MoEFCC framework. Statement 3 is incorrect: The Biological Diversity Act, 2002 regulates resource use and encourages sustainable use; it does not impose a complete blanket ban on eco-tourism.

Q2. Consider the following statements regarding aquatic ecosystem dynamics: Statement-I: Excessive growth and subsequent decay of unharvested plant biomass in stagnant water bodies can contribute to localized greenhouse gas emissions. Statement-II: Anaerobic decomposition of organic matter by methanogenic micro-organisms in oxygen-depleted bottom layers converts organic carbon into methane gas. Which one of the following is correct in respect of the above statements?

  1. Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
  2. Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
  3. Statement-I is correct but Statement-II is incorrect
  4. Statement-I is incorrect but Statement-II is correct

Answer: A. Both statements are factually correct. Statement-II accurately provides the biological mechanism (anaerobic decomposition by methanogens in oxygen-starved aquatic environments) that explains why massive plant decay generates methane gas (Statement-I).

Q3. With reference to wetland conservation, which of the following best describes the ecological risk associated with unchecked, dense growth of surface water lilies or aquatic weeds?

  1. It permanently eliminates soil nitrogen fixation across surrounding agricultural landscapes.
  2. It leads to eutrophication and light blockage, deteriorating water quality and dissolved oxygen.
  3. It increases dissolved oxygen by boosting nocturnal photosynthetic activity of benthic fauna.
  4. It enhances vertical percolation rates, causing rapid drying up of shallow coastal aquifers.

Answer: B. Dense mats of surface aquatic plants prevent light from penetrating into deeper water layers, inhibiting photosynthesis by submerged macrophytes. This leads to dissolved oxygen depletion, habitat degradation, and accelerated eutrophication. Options A, C, and D are scientifically incorrect mechanisms.

Revision flashcards

  • Under which parent legislation are State Biodiversity Boards (SBBs) established in India? The Biological Diversity Act, 2002. SBBs act as statutory bodies advising state governments on biodiversity conservation and sustainable resource utilization.
  • What is the primary statutory function of local Biodiversity Management Committees (BMCs)? Documenting local biological diversity through People's Biodiversity Registers (PBRs) and regulating access and benefit-sharing under the Biological Diversity Act, 2002.
  • In October 2026, which region in Kerala was reported by the State Biodiversity Board to face aquatic disruption from post-flood water lily growth? Malarikkal in Kottayam district, Kerala, where a massive water lily bloom proliferated following the 2018 Kerala floods.
  • What key ecological impacts were flagged by the Kerala State Biodiversity Board in October 2026 regarding water lily growth in Malarikkal? Blockage of sunlight penetration, altered hydraulic flow, native plant displacement, and methane emissions from decaying biomass.
  • Why does decaying aquatic weed biomass in stagnant water bodies produce methane gas? Oxygen depletion creates anaerobic conditions where methanogenic bacteria decompose organic matter, converting biomass into methane, a potent greenhouse gas.

All stories for 17 October 2026 · ← 16 October 2026