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7th May 2025-Current Affairs

by | May 7, 2025 | Current Affairs

1. Study Notes: Indus Waters Treaty (IWT) – India’s Suspension and Its Strategic Messaging – InternationaI Relations

Why in News?

  • On April 24, 2025, India announced that it is holding the Indus Waters Treaty (IWT) in abeyance.
  • Triggered by the April 22 Pahalgam terror attack, this move signals India’s frustration with Pakistan’s continued support for cross-border terrorism.
  • Marks a major strategic and diplomatic shift from India’s earlier position of honoring the IWT despite hostilities.

What Does ‘Abeyance’ Mean in This Context?

  • Abeyance implies a temporary suspension rather than termination.
  • It is a non-legal term in the context of treaties.
  • International law ambiguity:
    • Neither the IWT nor the Vienna Convention on the Law of Treaties (VCLT) formally recognizes ‘abeyance’ as a legal category.
    • India is not a signatory to VCLT, while Pakistan has signed but not ratified it.

Legal Implications

  • Articles XII(3) & XII(4) of the IWT:
    • Clearly state that any modification or termination of the treaty requires mutual consent.
    • India’s unilateral action challenges this legal framework, risking international legal scrutiny.
  • Possibility of legal proceedings in international forums, though India may contest jurisdiction.

Diplomatic Messaging and Strategic Intent

  • India’s action serves two strategic purposes:
    • A stronger stance on terrorism, especially after repeated provocations.
    • A symbolic pressure tactic to convey that cooperation (even on water) cannot be delinked from security.
  • It reflects a domestic political strategy too—projecting resolve and deterring adversaries.

Environmental and Operational Risks

  • Holding back data and notifications under the IWT affects:
    • Pakistan’s water security, especially for agricultural planning.
    • The ecological balance in the shared Indus Basin.
  • If India accelerates water diversion or dam projects:
    • Risks of poorly planned water infrastructure.
    • Flood risks and regional instability due to ecological disruption.

Broader Implications for India-Pakistan Relations

  • Could worsen diplomatic ties, especially with Pakistan likely to raise the issue in international forums.
  • Might erode the few remaining bilateral frameworks of cooperation.
  • Sets a precedent of weaponizing shared resources—a risky step for long-term diplomacy.

Balancing Act Ahead for India

India must navigate:

  • Security concerns vis-à-vis terrorism.
  • International legal obligations and reputation.
  • Ecological and technical feasibility of shifting water flows.
  • Risks of global perception turning against India if viewed as breaching a humanitarian or cooperative framework.

Summary

India’s move to place the Indus Waters Treaty in abeyance reflects a strategic and symbolic response to Pakistan’s inaction on cross-border terrorism. While this signals a tougher diplomatic line, it invites significant legal and environmental concerns. The term ‘abeyance’ is not supported by treaty or international law frameworks, making India’s unilateral move controversial. Success of this strategy depends on India’s ability to balance legal risks, ecological sustainability, and global diplomatic standing.

Exam Connect – Possible Questions

Prelims

  1. Which of the following treaties governs the sharing of rivers between India and Pakistan?
    A) Ganga Waters Agreement
    B) Indus Waters Treaty
    C) Brahmaputra Accord
    D) Teesta Water Sharing Treaty
    Answer: B) Indus Waters Treaty

  2. India is not a party to which of the following international legal instruments?
    A) UN Charter
    B) Vienna Convention on the Law of Treaties (VCLT)
    C) Paris Agreement
    D) Hague Convention
    Answer: B) Vienna Convention on the Law of Treaties (VCLT)

  3. According to the Indus Waters Treaty, modification or termination of the treaty requires:
    A) Approval of the United Nations
    B) Parliamentary ratification in both countries
    C) Mutual consent of India and Pakistan
    D) Mediation by the World Bank
    Answer: C) Mutual consent of India and Pakistan

Mains

  1. “India’s decision to hold the Indus Waters Treaty in abeyance marks a strategic shift in foreign policy.” Discuss the implications of this move for regional water security and international legal norms.
  2. Analyze how the suspension of the Indus Waters Treaty aligns or conflicts with India’s commitment to international treaties and ecological sustainability.
  3. Critically examine the use of transboundary water treaties as a strategic tool in conflict resolution and deterrence in South Asia.

2. OBC Quotas in Urban Local Bodies – Jharkhand and the Triple Test – Polity

Why in News?

  • Jharkhand has completed the data collection process for implementing OBC reservations in Urban Local Bodies (ULBs).
  • The process complies with the Supreme Court’s “Triple Test” criteria, ensuring constitutional validity and data-driven decision-making in quota allocation.

Constitutional and Legal Context

Background on OBC Reservations in ULBs

  • Reservations for Other Backward Classes (OBCs) in urban governance are not automatic.
  • The Supreme Court ruling in Vikas Kishanrao Gawali vs State of Maharashtra (2021) mandated a “Triple Test” to ensure that such reservations:
    • Are evidence-based,
    • Ensure fairness, and
    • Stay within the constitutional 50% reservation ceiling (as per Indra Sawhney judgment, 1992).

The Triple Test Criteria Explained

  1. Empirical Inquiry by a Dedicated Commission
    • A State Backward Classes Commission must collect quantifiable data on the political backwardness of OBCs.
  2. Recommendations on Quota Percentage
    • Based on data, the commission must recommend an appropriate reservation percentage.
  3. Reservation Ceiling
    • Total reservations, including SC/ST/OBC, must not exceed 50% of the total seats in ULBs (as a general rule).

Implementation in Jharkhand

OBC Commission Formation

  • Jharkhand established the OBC Commission in June 2023.
  • It modeled its approach after Madhya Pradesh, which had previously complied with the Triple Test for ULB elections.

Data Collection Process

  • Conducted between December 2023 and March 2024.
  • Data was submitted despite delays in some districts.
  • Institutions like IIM and XLRI are involved in analyzing the data for socio-economic and political backwardness.

OBC Classification in Jharkhand

  • Approx. 50% of Jharkhand’s population is OBC.
  • Two sub-groups:
    • BC-I: Socially and educationally more backward (127 castes).
    • BC-II: Relatively better off (45 castes).

Significance of Jharkhand’s Initiative

Model for Other States

  • Jharkhand’s successful execution of the Triple Test offers a replicable model for other Indian states.
  • Promotes data-backed policy, inclusion, and legal compliance.

Strengthening Grassroots Democracy

  • Ensures fair political representation for OBCs at the local level.
  • Enhances participatory governance and inclusivity in urban administration.

Summary

Jharkhand’s completion of data collection for OBC reservations in Urban Local Bodies (ULBs) aligns with the Supreme Court’s “Triple Test” framework, ensuring constitutional compliance and data-driven governance. The initiative marks a pivotal step in strengthening inclusive local governance and can serve as a model for other states. With around 50% of its population belonging to the OBC category, Jharkhand’s approach highlights a balanced pursuit of social justice and legal integrity.

Exam Connect – Possible Questions

Prelims

  1. The Supreme Court’s “Triple Test” is related to:
    A) Criminal justice reform
    B) Interstate water disputes
    C) Reservations for OBCs in local bodies
    D) Educational quotas for minorities
    Answer: C) Reservations for OBCs in local bodies

  2. Which of the following statements is true regarding the “Triple Test”?
    1. It requires a dedicated backward classes commission to collect data.
    2. It mandates reservations to be based on empirical data.
    3. It removes the 50% cap on total reservations.
      A) 1 and 2 only
      B) 2 and 3 only
      C) 1 and 3 only
      D) All of the above
      Answer: A) 1 and 2 only

  3. Which constitutional article governs reservations in Panchayats and Municipalities?
    A) Article 15
    B) Article 243D and 243T
    C) Article 16
    D) Article 330
    Answer: B) Article 243D and 243T

Mains

  1. “The Triple Test laid down by the Supreme Court ensures that reservation in local bodies is constitutionally compliant and data-driven.” Discuss this statement in the context of recent developments in Jharkhand.
  2. Examine the constitutional and legal framework governing OBC reservations in Urban Local Bodies. How does Jharkhand’s model attempt to balance social justice with legal compliance?
  3. Critically analyze the challenges faced by states in implementing the Triple Test for local body reservations and suggest measures to strengthen inclusive urban governance.

3. Kaleshwaram Lift Irrigation Project (KLIP) – Economy

Why in News?

  • The National Dam Safety Authority (NDSA), in April 2024, reported critical structural and operational defects in the Kaleshwaram Lift Irrigation Project (KLIP).
  • Notably, Pillar No. 20 of the Medigadda barrage sank in October 2023, leading to flooding and damage.
  • NDSA noted “irreparable damage” to three key barrages, sparking debates over safety, accountability, and viability.

Project Overview: KLIP

Objective:

  • Designed to lift and store 240 TMC (thousand million cubic feet) of water.
  • Intended to:
    • Irrigate 45 lakh acres of farmland.
    • Supply drinking water to Hyderabad and surrounding districts.
    • Support industrial use in Telangana.

Scale and Infrastructure:

  • World’s largest multi-stage lift irrigation project.
  • Inaugurated: June 21, 2019.
  • Components:
    • 7 links and 28 packages.
    • Covers 500 km, with 1800+ km canal network.
    • 20 reservoirs.
    • Asia’s largest underground pump house at Ramadugu.

Financial Implications:

  • Estimated cost: ₹80,000 crore to ₹1.2 lakh crore.
  • Annual debt servicing (interest + principal): Approx. ₹16,000 crore.
  • Heavy fiscal burden raising questions about long-term sustainability.

Key Issues and Challenges

1. Structural Defects

  • NDSA Report (April 2024):
    • Identified poor design, inadequate safety protocols, and construction flaws.
    • Three barrages including Medigadda, Annaram, and Sundilla are affected.
    • Declared parts of the infrastructure as irreparably damaged.

2. Financial Viability

  • Massive investment with doubtful returns due to:
    • Delayed implementation of irrigation goals.
    • High Operation & Maintenance (O&M) costs.
    • Dependence on loan-based financing.

3. Governance and Oversight

  • Allegations of lack of transparency, irregular approvals, and inadequate quality control.
  • Highlights the need for stronger institutional checks in infrastructure execution.

Strategic and Environmental Context

River Basin Context: Godavari

  • The KLIP draws water from the Godavari River, also called Dakshin Ganga.
  • Origin: Trimbakeshwar, Maharashtra.
  • Length: 1465 km, flowing into the Bay of Bengal.
  • Basin includes: Maharashtra, Telangana, Andhra Pradesh, Chhattisgarh, Odisha, Madhya Pradesh, Karnataka, and Puducherry.

Environmental Risks

  • Risk of submergence, soil erosion, and disruption of natural hydrology.
  • Unaddressed impact on aquatic ecosystems and forest areas.

Summary

The Kaleshwaram Lift Irrigation Project, one of the world’s largest and most ambitious water infrastructure initiatives, is facing serious scrutiny due to structural failures and high financial burdens. With reports from the National Dam Safety Authority pointing to irreparable damage in key barrages, questions are now being raised about the project’s design integrity, sustainability, and governance. While KLIP aims to provide irrigation and drinking water to Telangana, its long-term viability is now under threat.

Exam Connect – Possible Questions

Prelims

  1. The Kaleshwaram Lift Irrigation Project is primarily built on which river?
    A) Krishna
    B) Godavari
    C) Tungabhadra
    D) Mahanadi
    Answer: B) Godavari

  2. Which of the following statements about the Kaleshwaram Project is correct?
    1. It aims to irrigate more than 40 lakh acres of land.
    2. It includes Asia’s largest underground pump house.
    3. It draws water from the Ganga River.
      A) 1 and 2 only
      B) 2 and 3 only
      C) 1 and 3 only
      D) All of the above
      Answer: A) 1 and 2 only

  3. The National Dam Safety Authority (NDSA) functions under the jurisdiction of:
    A) Ministry of Environment, Forest and Climate Change
    B) Ministry of Jal Shakti
    C) NITI Aayog
    D) Central Water Commission
    Answer: B) Ministry of Jal Shakti

Mains

  1. The Kaleshwaram Lift Irrigation Project was envisioned as a game changer for Telangana’s water security. Critically examine the structural and economic challenges now threatening its success.
  2. Discuss the role of institutional oversight, such as the National Dam Safety Authority, in ensuring the sustainability and safety of large-scale infrastructure projects in India.
  3. Evaluate the environmental and socio-economic implications of mega lift irrigation projects in India, with specific reference to KLIP.

4. SVAMITVA Scheme – Transforming Rural Land Governance

Why in News?

  • India is set to present the SVAMITVA Scheme at the World Bank Land Conference, highlighting its role in:
    • Land governance reform
    • Climate action
    • Rural empowerment
  • The scheme is gaining international recognition for its innovative use of technology in land administration.

Overview of the SVAMITVA Scheme

Full Form:

Survey of Villages Abadi and Mapping with Improvised Technology in Village Areas

Launched:

  • 24 April 2020 by the Ministry of Panchayati Raj

Type:

  • Central Sector Scheme (fully funded by the Government of India)

Key Collaborators:

  • Ministry of Panchayati Raj
  • State Revenue Departments
  • Survey of India (technical implementation partner)

Objectives of the Scheme

  1. Provide legal ownership of residential land in rural areas.
  2. Reduce land-related disputes through accurate land mapping.
  3. Promote financial inclusion by enabling property to be used as a financial asset.
  4. Improve rural governance and empower Gram Panchayats through digital tools.

Key Features

1. Use of Technology

  • Drone surveys for high-resolution mapping of residential land.
  • Continuous Operating Reference System (CORS) enhances mapping accuracy to within 5 cm.

2. Property Cards

  • Provide legal ownership documents to residents.
  • Examples:
    • Gharauni – Uttar Pradesh
    • Adhikar Abhilekh – Madhya Pradesh

3. Integration with Gram Manchitra Platform

  • Assists Gram Panchayats in:
    • Development planning
    • Infrastructure management
    • Disaster risk mitigation

Broader Impact

1. Economic Empowerment

  • Helps monetize rural assets by enabling use of property as collateral.
  • Unlocks land value potential of USD 1.162 trillion.

2. Dispute Resolution

  • Reduces land conflicts through clear demarcation and documentation.

3. Climate and Development Planning

  • Enables sustainable land-use planning.
  • Enhances rural resilience through better management of resources and risks.

4. Cooperative Federalism

  • Encourages coordination between Centre and States, fostering decentralized governance.

Summary

The SVAMITVA Scheme, launched in 2020, is a pioneering rural land governance initiative that uses drone and geospatial technologies to provide legal ownership of residential properties in Indian villages. By issuing property cards and integrating village-level planning tools like Gram Manchitra, the scheme reduces land disputes, boosts rural financial inclusion, and supports climate-resilient development. Its presentation at the World Bank Land Conference underscores its global relevance and potential to serve as a model for developing countries.

Exam Connect – Possible Questions

Prelims

  1. SVAMITVA Scheme is primarily implemented by which ministry?
    A) Ministry of Rural Development
    B) Ministry of Housing and Urban Affairs
    C) Ministry of Panchayati Raj
    D) Ministry of Finance
    Answer: C) Ministry of Panchayati Raj

  2. Which of the following technologies is/are used under the SVAMITVA Scheme?
    1. Satellite imagery
    2. Drone-based surveys
    3. Geospatial mapping
    4. Blockchain
      A) 2 and 3 only
      B) 1 and 2 only
      C) 1, 2 and 3 only
      D) All of the above
      Answer: C) 1, 2 and 3 only

  3. The Gram Manchitra platform is used for:
    A) Village-level sports competitions
    B) Management of urban property taxes
    C) Rural development planning and disaster risk mitigation
    D) Implementation of MNREGA payments
    Answer: C) Rural development planning and disaster risk mitigation

Mains

  1. “The SVAMITVA Scheme marks a shift towards data-driven and technology-enabled rural governance.” Discuss its significance in resolving land disputes and promoting inclusive development.
  2. Examine the role of geospatial technologies in strengthening land governance in India, with reference to the SVAMITVA Scheme.
  3. How does the SVAMITVA Scheme support the twin goals of cooperative federalism and rural financial inclusion?

5. INS Sharda’s HADR Exercise in the Maldives – InternationaI Relations

Why in News?

  • INS Sharda, an Indian Navy offshore patrol vessel, is participating in its first Humanitarian Assistance and Disaster Relief (HADR) exercise at Maafilaafushi Atoll, Maldives from May 4 to May 10, 2025.
  • This deployment reflects India’s growing maritime cooperation in the Indian Ocean Region (IOR), aligned with the Neighbourhood First and MAHASAGAR visions.

🇮🇳 Strategic Context

Neighbourhood First Policy

  • Prioritizes bilateral relations with India’s immediate neighbors.
  • Seeks to strengthen regional stability, economic ties, and security cooperation.

MAHASAGAR Vision

  • Announced by the Indian PM in Mauritius.
  • Focuses on:
    • Mutual Security
    • Shared growth in the Indian Ocean Region (IOR)
    • India as a net security provider and first responder in regional crises.

About INS Sharda

  • Class: Offshore Patrol Vessel (OPV)
  • Role includes:
    • Maritime surveillance
    • Anti-piracy and HADR missions
    • Ensuring maritime domain awareness
  • Ideal platform for regional exercises due to versatility and extended operational reach.

Objectives of the HADR Exercise

  1. Enhancing Interoperability
    • Between the Indian Navy and the Maldives National Defence Force (MNDF)
  2. Search and Rescue (SAR) Operations
    • Conducted in coastal zones and open sea to test response readiness
  3. Disaster Response and Logistics
    • Coordination in relief distribution, evacuation, and infrastructure restoration
  4. Medical Assistance and Training
    • Onboard and onshore treatment simulations
    • Capacity-building sessions for local responders
  5. Community Engagement
    • Disaster awareness programs for local populations
    • Promoting grassroots-level preparedness

Significance of the Exercise

Strategic Importance

  • Reinforces India-Maldives defence cooperation, already strong through past patrols, capacity-building, and bilateral agreements.

Maritime Security

  • Ensures collective readiness for natural disasters like tsunamis, cyclones, and maritime accidents.

India’s Role as a Net Security Provider

  • Strengthens India’s position in the Indian Ocean as a trusted partner for peace, security, and disaster response.

Regional Diplomacy

  • Builds soft power and trust through humanitarian engagement rather than hard military posture.

Summary

INS Sharda’s maiden participation in a HADR exercise in the Maldives is a strategic milestone in India’s maritime diplomacy. Anchored in the Neighbourhood First and MAHASAGAR visions, the exercise aims to enhance regional preparedness for disasters through joint drills, medical support, and community awareness. It also reinforces India’s image as a net security provider in the Indian Ocean, while deepening strategic ties with the Maldives.

Exam Connect – Possible Questions

Prelims

  1. The MAHASAGAR vision of India is associated with which of the following?
    A) Inland waterways development
    B) Net-zero carbon shipping by 2050
    C) Maritime security and regional cooperation in the Indian Ocean
    D) Exclusive economic zone mapping
    Answer: C) Maritime security and regional cooperation in the Indian Ocean

  2. Which of the following are objectives of Humanitarian Assistance and Disaster Relief (HADR) exercises?
    1. Search and Rescue Operations
    2. Maritime surveillance
    3. Medical assistance and disaster preparedness
      A) 1 and 3 only
      B) 2 and 3 only
      C) 1 and 2 only
      D) All of the above
      Answer: A) 1 and 3 only

  3. Which of the following best describes INS Sharda?
    A) Submarine-launched ballistic missile
    B) Amphibious assault ship
    C) Offshore patrol vessel
    D) Aircraft carrier
    Answer: C) Offshore patrol vessel

Mains

  1. “India’s participation in HADR exercises strengthens its maritime diplomacy and regional leadership in the Indian Ocean Region.” Discuss with reference to the INS Sharda deployment in the Maldives.
  2. Evaluate the significance of the MAHASAGAR vision in shaping India’s maritime engagement with small island nations in the Indian Ocean.
  3. Discuss the role of Humanitarian Assistance and Disaster Relief (HADR) initiatives in promoting soft power and regional cooperation.

6. Hydrogen vs Battery – The Cost of Clean Public Transport – Economy

Why in News?

  • A study in The Lancet reported that between 2008 and 2019, high PM2.5 levels contributed to ~30,000 deaths annually across 10 major Indian cities.
  • Amid rising urban air pollution, Fuel Cell Electric Vehicles (FCEVs) are emerging as a viable clean public transport alternative, particularly for long-distance travel, compared to Battery Electric Vehicles (BEVs).

Public Health and Air Pollution

PM2.5 and Mortality

  • PM2.5: Fine particulate matter smaller than 2.5 microns, capable of penetrating deep into lungs and bloodstream.
  • Health Impact:
    • ~30,000 pollution-related deaths annually in 10 major cities.
    • In Mumbai, ~5,100 deaths/year due to PM2.5.
    • Contributes to ~7.2% of total urban deaths in affected cities.

Implication

  • Indicates a severe urban public health crisis linked to air quality.
  • Calls for clean mobility solutions as part of a comprehensive pollution mitigation strategy.

Technology Comparison: FCEVs vs. BEVs

FeatureFCEVs (Fuel Cell Electric Vehicles)BEVs (Battery Electric Vehicles)
Energy SourceHydrogen fuel cellsRechargeable lithium-ion batteries
Driving Range500–700 km200–400 km (typical)
Refuelling Time5–15 minutes30 minutes to several hours
WeightLighter (no heavy battery pack)Heavier due to large battery units
Best Use CaseLong-haul transport, buses, commercialShort city commutes, private vehicles
EmissionsZero tailpipe emissionsZero tailpipe emissions
InfrastructureHydrogen refuelling stations neededCharging stations more widespread
Cost TrajectoryCost parity expected by 2030Currently cheaper, but range-limited

🇮🇳 India’s Clean Mobility Landscape

Policy Support

  • FAME-II (Faster Adoption and Manufacturing of Hybrid and Electric Vehicles): Supports BEVs and charging infra.
  • Green Hydrogen Mission (2023): Aims to position India as a hub for hydrogen production and use.

Current Focus

  • BEVs dominate India’s EV market (e.g., two-wheelers, e-autos).
  • FCEVs are still nascent, but potential is high for public transport and logistics.

Looking Ahead: 2030 and Beyond

  • Experts forecast cost convergence between FCEVs and BEVs by 2030, driven by:
    • Mass production
    • Improved hydrogen infrastructure
    • Technological innovation
  • FCEVs could be crucial in achieving:
    • Net-zero goals
    • Pollution reduction in cities
    • Reliable long-range green transport

Summary

India is facing a growing public health crisis due to urban air pollution, with fine particulate matter (PM2.5) contributing to tens of thousands of deaths annually. While Battery Electric Vehicles (BEVs) have gained traction, Fuel Cell Electric Vehicles (FCEVs) offer a promising solution for long-range and heavy-duty transport. With rapid technological progress and policy backing, FCEVs are expected to reach cost parity with BEVs by 2030, presenting a strong case for their integration into India’s public transport system.

Exam Connect – Possible Questions

Prelims

  1. PM2.5 refers to:
    A) Particulate matter smaller than 5 microns
    B) Particulate matter smaller than 2.5 microns
    C) Particulate matter between 2.5 and 10 microns
    D) Sulphur dioxide emission levels
    Answer: B) Particulate matter smaller than 2.5 microns

  2. Which of the following are advantages of Fuel Cell Electric Vehicles (FCEVs) over Battery Electric Vehicles (BEVs)?
    1. Shorter refuelling time
    2. Greater driving range
    3. Higher greenhouse gas emissions
      A) 1 and 2 only
      B) 2 and 3 only
      C) 1 and 3 only
      D) All of the above
      Answer: A) 1 and 2 only

  3. The Green Hydrogen Mission launched by the Government of India primarily aims to:
    A) Promote solar-powered EVs
    B) Replace LPG with biofuels
    C) Enable large-scale hydrogen production and use
    D) Reduce nitrogen oxide emissions in urban areas
    Answer: C) Enable large-scale hydrogen production and use

Mains

  1. “Fuel Cell Electric Vehicles offer a viable alternative to battery-powered transport in India’s clean mobility transition.” Discuss with reference to urban air pollution and long-distance travel needs.
  2. Analyze the challenges and opportunities associated with hydrogen fuel as a sustainable energy source for India’s transport sector.
  3. What policy measures are needed to accelerate the adoption of FCEVs in India while addressing the challenges of infrastructure and cost?

7. Microplastics and the Ocean’s Carbon Cycle – Environment

Why in News?

  • A recent study in Nature highlights that microplastics are significantly disrupting the ocean’s carbon and biogeochemical cycles.
  • This revelation emphasizes the far-reaching environmental and climate-related consequences of plastic pollution beyond surface-level marine degradation.

What are Microplastics?

Definition:

  • Plastic particles ranging from 1 to 100 micrometres in size.
  • Distinct from larger plastic debris (100–5,000 micrometres) typically found on or near the ocean surface.

Origin:

  • Common sources include:
    • Fishing gear (nylon, polyester nets),
    • Textile fibres (especially polyester),
    • Atmospheric deposition (0.013–25 million tonnes annually),
    • Plastic waste runoff from land-based sources.

Oceanic Distribution

Findings from the Study:

  • Based on data from 1,885 ocean stations (2014–2024).
  • Microplastics were predominantly found:
    • In subsurface layers (up to 100 metres deep),
    • Especially concentrated within ocean gyres – rotating currents that trap floating debris.
  • Over 56 types of polymers detected, with buoyant plastics being most prevalent.

Disruption of the Ocean’s Carbon Cycle

Allochthonous Carbon:

  • Refers to carbon introduced from external sources—not generated within the marine ecosystem.
  • Plastics act as a significant source of non-biological (allochthonous) carbon in marine environments.

Carbon Cycle Impact:

  1. Distortion of Natural Carbon Ratios:
    • Plastic-derived carbon alters the composition of Particulate Organic Carbon (POC).
    • Radiocarbon dating of POC becomes misleading—appears ~420 years older due to lack of radiocarbon in plastic.
  2. Microbial and Biogeochemical Disruption:
    • Microbes ingest plastic particles, affecting:
      • Nutrient cycles (e.g., nitrification, denitrification),
      • Decomposition of organic matter.
    • Impacts food webs and biological carbon pump efficiency.

Impact on Marine Ecosystems

  • Alters plankton and microbial food chains.
  • Reduces biodiversity and interferes with reproductive and metabolic functions of marine organisms.
  • Threatens the stability of oceanic ecosystems, with climate change feedback implications.

Summary

Microplastics, largely originating from fishing gear, textiles, and atmospheric deposition, are now being detected deep in ocean layers, where they interfere with microbial processes and disrupt the marine carbon cycle. These plastics act as a source of allochthonous carbon, distorting the composition and radiocarbon age of Particulate Organic Carbon (POC). This interference affects nutrient cycling, microbial activity, and food chains, posing significant ecological and climate-related threats. Addressing this challenge requires urgent global action to regulate plastic production, improve waste management, and enhance marine monitoring.

Exam Connect – Possible Questions

Prelims

  1. Which of the following best defines allochthonous carbon?
    A) Carbon fixed by autotrophs within the ecosystem
    B) Carbon originating from fossil fuels used in agriculture
    C) Carbon introduced from external sources into an ecosystem
    D) Carbon released during volcanic activity
    Answer: C) Carbon introduced from external sources into an ecosystem

  2. Which of the following are effects of microplastics on ocean biogeochemical cycles?
    1. Disruption of nitrification and denitrification
    2. Alteration of particulate organic carbon composition
    3. Increased ocean acidification
      A) 1 and 2 only
      B) 2 and 3 only
      C) 1 and 3 only
      D) All of the above
      Answer: A) 1 and 2 only

  3. Ocean gyres are significant in the context of plastic pollution because:
    A) They are underwater volcanic zones
    B) They are nutrient-rich fishing zones
    C) They trap and accumulate plastic debris due to circulating currents
    D) They are areas of upwelling and carbon fixation
    Answer: C) They trap and accumulate plastic debris due to circulating currents

Mains

  1. “Microplastics have evolved from a pollution concern to a climate threat.” Analyze this statement in the context of recent findings on the ocean carbon cycle.
  2. Discuss the role of microplastics as a source of allochthonous carbon in marine systems. How does this affect ocean biogeochemistry and carbon sequestration?
  3. Evaluate the implications of deep-sea microplastic pollution for marine biodiversity and climate regulation. Suggest measures to mitigate their entry and accumulation in oceans.