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GS Paper: GS3

  • How groundwater contamination is fuelling chronic illnesses

    India’s groundwater is increasingly getting contaminated with toxic substances. Over 85% of rural drinking water and 65% of irrigation needs are met through groundwater, yet unregulated extraction, industrial waste, agricultural runoff, and poor sanitation have turned this life source into a silent killer.

    Scale of the Crisis

    The 2024 Annual Groundwater Quality Report by the Central Ground Water Board (CGWB) reported the following:

    1. Nitrates: Found in 20%+ samples (due to chemical fertilisers & septic tank leakage).
    2. Fluoride: Detected in 9%+ samples, leading to skeletal & dental fluorosis.
    3. Arsenic: Found in parts of Punjab, Bihar, Uttar Pradesh causing cancers & neurological damage.
    4. Uranium: Detected in Punjab, Andhra Pradesh, Rajasthan linked to kidney damage.
    5. Heavy metals: Iron, lead, cadmium, chromium, causing developmental & immune system issues.

    Major Contaminants and Health Impacts

    • Fluoride Contamination: 
      1. Affects 230 districts across 20 states.
      2. Health impact: Skeletal fluorosis, stunted growth, joint pain.
      3. Rajasthan, MP, and UP report high prevalence.
      4. Example: Jhabua (MP) – 40% of tribal children affected
    • Arsenic Exposure:
      1. Concentrated in Gangetic belt.
      2. Health impact: Skin lesions, respiratory illness, cancers (skin, liver, kidney, bladder).
      3. Example: Ballia (UP) – Arsenic 200 g/L (20× WHO limit) linked to 10,000+ cancer cases.
    • Nitrate Pollution: 
      1. 56% districts exceed safe limits.
      2. Health impact: Blue Baby Syndrome in infants, gastrointestinal distress.
      3. Driven by fertilisers & poor waste management.
    • Uranium Contamination:
      1. Increasing due to over-extraction & phosphate fertilisers.
      2. Health impact: Nephrotoxicity, chronic organ damage.
      3. Example: Malwa (Punjab) – 66% samples risky for children.
    • Heavy Metal Pollution: 
      1. Sources: Industrial discharge, mining.
      2. Health impact: Neurological issues, anaemia, developmental delays.

    Groundwater Death Zones: Case Studies

    1. Budhpur, Baghpat (UP) – 13 deaths in 2 weeks from kidney failure linked to industrial waste.
    2. Jalaun (UP) – Petroleum-like fluids from hand pumps due to underground fuel leaks.
    3. Paikarapur (Bhubaneswar) – Sewage leakage caused illness in hundreds.

    Why the Crisis Persists: Root Causes and Systemic Failures:

    1. Institutional Fragmentation: Various agencies like the CGWB, the CPCB, the SPCBs, and the Ministry of Jal Shakti operate in silos, leading to a lack of a unified, coordinated approach.
    2. Weak Legal Enforcement: The Water (Prevention and Control of Pollution) Act, 1974, has inadequate provisions for groundwater. This, combined with lax enforcement and regulatory loopholes, emboldens polluters.
    3. Lack of Real-Time Data: Monitoring is infrequent and poorly disseminated. Without early warning systems, contamination is often discovered only after serious health consequences have emerged.
    4. Excessive Groundwater Extraction: Over-pumping lowers water tables and concentrates pollutants, making aquifers more vulnerable to both geogenic toxins and industrial contaminants.
    5. Deficient Waste Management: Inadequate industrial effluent treatment and poor sanitation infrastructure, especially in rural areas, allow pollutants to seep directly into aquifers

    The Way Forward: A Multi-Dimensional Strategy

    Addressing this crisis requires a bold, multi-dimensional strategy that integrates regulation, technology, health, and public participation.

    1. National Framework: Enact a comprehensive National Groundwater Pollution Control Framework with clear legal authority to regulate groundwater use and discharge.
    2. Modern Monitoring Infrastructure: Deploy real-time monitoring systems using sensors and public dashboards to create an early warning network.
    3. Targeted Remediation: Implement targeted interventions for specific contaminants, such as defluoridation plants in high-fluoride zones and arsenic removal technologies in affected regions.
    4. Waste Management Reforms: Enforce strict industrial effluent treatment norms and promote sustainable agricultural practices to reduce the use of chemical fertilizers.
    5. Citizen-Centric Governance: Empower local communities through Jal Gram Sabhas to manage local water resources, conduct community water testing, and raise public awareness.

    Value Addition: Key Concepts:

    • Geogenic Contamination: Naturally occurring pollutants like arsenic and fluoride mobilized by human activity.
    • Anthropogenic Contamination: Human-induced pollution from industries, agriculture, and urban waste.
    • Skeletal Fluorosis: A debilitating condition causing bone deformities.
    • Methemoglobinemia (“Blue Baby Syndrome”): A potentially fatal condition in infants caused by nitrate-laced water.

    Practice UPSC MAINS question:

    “Groundwater pollution in India is no longer about scarcity—it is about safety and survival.” Discuss this statement with recent examples and suggest a multi-pronged approach to tackle this issue.

     

  • District Flood Severity Index (DFSI)

    Why in the News?

    Researchers from IIT Delhi and IIT Gandhinagar have developed a District Flood Severity Index (DFSI) to aid flood planning using past data and human impact indicators.

    About the District Flood Severity Index (DFSI):

    • Objective: To provide a comprehensive, data-based assessment of flood severity across Indian districts.
    • Focus: District-level analysis, as districts are the core units for planning and implementation of disaster management in India.
    • Based on long-term data (since 1967): Collected annually by the India Meteorological Department (IMD) on major flood events.
    • Significance: Responds to the lack of an official national index that incorporates human impact, not just flood magnitude.

    Key Parameters Used in DFSI:

    The index incorporates multiple indicators to measure both the scale and impact of flooding:

    1. Mean duration (in days) of flood events per district.
    2. Percentage of district area historically affected by floods.
    3. Total deaths and injuries due to floods.
    4. Population of the district — used to assess per capita impact.
    5. 40-year curated dataset developed at IIT Delhi used for historical flood mapping.

    Key Insights from the Index:

    • Thiruvananthapuram (Kerala): Recorded the highest number of flood events (231), but does not feature in the top 30 most severely impacted districts as per DFSI.
    • Patna (Bihar): Ranked #1 on the severity index due to higher population impact and flood spread.
    • Assam districts like Dhemaji, Kamrup, and Nagaon consistently face high flood frequency (178+ events), but ranking depends on combined indicators.

     

    [UPSC 2014] What are the benefits of implementing the ‘Integrated Watershed Development Programme’?”

    1. Prevention of soil runoff 2. Linking the country’s perennial rivers with seasonal rivers

    3. Rainwater harvesting and recharge of groundwater table 4. Regeneration of natural vegetation

    Options: (a) 1 and 2 only (b) 2, 3 and 4 only (c) 1, 3 and 4 only* (d) 1, 2, 3 and 4 only

     

  • Prophylaxis Therapy for Haemophilia

    Why in the News?

    With haemophilia care evolving globally, the shift from reactive to preventive treatment has brought Prophylaxis Therapy to the forefront of modern clinical practice.

    About Haemophilia:

    • What is it: Rare genetic bleeding disorder due to deficiency of clotting factors, mainly Factor VIII (Haemophilia A).
    • Effect: Causes prolonged bleeding, even from minor injuries; can lead to internal bleeds in joints, muscles, or brain.
    • Key Symptoms: Excessive bleeding, painful joint swelling, risk of disability or brain hemorrhage.
    • Prevalence: Estimated 1–1.5 lakh cases in India; only ~29,000 diagnosed (~20%).
    • Underdiagnosis Causes: Low awareness, poor access to diagnostics, and socio-economic challenges.
    • Impact if Untreated: Each untreated bleed may reduce lifespan by ~16 days; leads to pain, disability, missed school/work, and job loss.

    Prophylaxis (Regular Replacement Therapy) and its Benefits:

    • What It Is: Regular infusion of clotting factors or non-factor therapies to prevent bleeds.
    • Global Standard: Replaces on-demand therapy; adopted as best practice in developed countries.
    • Joint Protection: Prevents recurrent bleeds, avoids deformities and long-term disability.
    • Quality of Life: Reduces pain and fear, enables normal schooling, work, and social life.
    • Healthcare Savings: Cuts emergency visits, hospital stays, and long-term costs.
    • Global Status: ~90% of haemophilia patients in developed countries are on prophylaxis.
    • India’s Progress: On-demand remains common; some states offer prophylaxis for children under 10.
    [UPSC 2021] In the context of hereditary diseases, consider the following statements:

    1.Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of the egg.

    2.A child inherits mitochondrial diseases entirely from the mother and not from the father.

    Which of the statements given above is/are correct?

    Options: (a) 1 only (b) 2 only (c) Both 1 and 2* (d) Neither 1 nor 2

     

  • Specie in news: Indian flapshell turtle (Lissemys punctata)

    Why in the News?

    The Social Forestry Department of Vadodara rescued an Albino Indian flapshell turtle (Lissemys punctata) from a freshwater lake in Chikhodra, Gujarat.

    Specie in news: Indian flapshell turtle (Lissemys punctata)

    About Indian Flapshell Turtle (Lissemys punctata):

    • Type: Small, freshwater softshell turtle native to South Asia
    • Unique Feature: Named for femoral flaps on the plastron that cover the limbs when retracted
    • Geographic Range: Found in India, Pakistan, Nepal, Bangladesh, Sri Lanka, and Myanmar
    • River Systems: Occurs in the Indus, Ganges, Irrawaddy, and Salween basins
    • Habitat: Prefers shallow, quiet freshwater bodies like rivers, ponds, lakes, marshes, tanks, and canals with muddy or sandy bottoms for burrowing
    • Conservation Status:
      • IUCN Red List: Vulnerable
      • CITES Listing: Appendix II
      • Wildlife (Protection) Act, 1972: Schedule I (maximum protection)
    • Major Threats:
      • Poaching for meat, blood-based potions, aphrodisiacs, and traditional medicine
      • Illegal trade for fishing bait, livestock feed, leather, and exotic pets
      • Habitat loss due to pollution, encroachment, and waterbody destruction
      • Albino individuals especially targeted in the illegal pet market
    [UPSC 2013] Consider the following fauna of India:

    1. Gharial 2. Leatherback turtle 3. Swamp deer

    Which of the above is/are endangered?

    Options: (a) 1 and 2 only (b) 3 only (c) 1, 2 and 3* (d) None

     

  • Yashoda AI Literacy Program

    Why in the News?

    The National Commission for Women (NCW) has launched “Yashoda AI”, an AI literacy program to empower women with skills in cybersecurity, digital privacy, and safe online practices, promoting digital inclusion across India.

    About Yashoda AI:

    • Launch: Introduced in May 2025 as an Artificial Intelligence Literacy Program for women.
    • Organisers: Joint initiative by the NCW and Future Shift Labs.
    • Objective: To train women in cybersecurity, digital privacy, and safe online practices.
    • Focus Areas: Covers AI-driven crimes, digital safety, and practical risk mitigation strategies.
    • Reach: Over 2,500 women trained to date.
    • Beneficiaries: Includes Self-Help Group members, local representatives (Sarpanchs, Pradhans, Mayors, Members of Legislative Assemblies), and frontline workers like Accredited Social Health Activists (ASHA workers).

    Back2Basics: National Commission for Women

    • Status: Statutory body established in 1992 under the NCW Act, 1990.
    • Composition: Consists of a Chairperson, 5 Members, and a Member-Secretary—appointed by the Central Government.
    • Term: All members serve for a term of 3 years.
    • Powers: Holds civil court powers during inquiries:
      • Can summon individuals and enforce attendance
      • Examine witnesses under oath
      • Demand records and receive affidavits
      • Issue commissions for examination of witnesses or documents

     

    [UPSC 2017] What is the purpose of Vidyanjali Yojana’?

    1. To enable the famous foreign campuses in India.

    2. To increase the quality of education provided in government schools by taking help from the private sector and the community.

    3. To encourage voluntary monetary contributions from private individuals and organizations so as to improve the infrastructure facilities for primary and secondary schools.

    Select the correct answer using the code given below:

    Options: (a) 2 only * (b) 3 only (c) 1 and 2 only (d) 2 and 3 only

     

  • Maryam Mirzakhani New Frontiers Prize

    Why in the News?

    Indian mathematician Dr. Rajula Srivastava has received the Maryam Mirzakhani New Frontiers Prize for her groundbreaking work in harmonic analysis and number theory.

    About the Indian Laureate: Dr. Rajula Srivastava

    • Affiliation: Hausdorff Center for Mathematics, University of Bonn and Max Planck Institute of Mathematics, Germany.
    • Field of Work:
      • Dr. Srivastava studied how to break down complex mathematical functions into simpler parts using advanced math tools.
      • She worked on finding how close certain numbers can get to specific points on curved shapes in higher dimensions.

    About the Maryam Mirzakhani New Frontiers Prize:

    • Purpose: Recognises early-career women mathematicians (within two years of PhD completion) for outstanding research contributions.
    • Named After: Maryam Mirzakhani — first woman and first Iranian to win the Fields Medal; known for her work on geometry and Riemann surfaces.
    • Objective: To honour Mirzakhani’s legacy, encourage more women in mathematics, and elevate early-career contributions.
    • Established: November 2019 by the Breakthrough Prize Foundation.
    • Prize Amount: $50,000, may be shared by multiple recipients in a year.
    • Eligibility: Women mathematicians who have:
      • Recently completed their PhD (within 2 years)
      • Shown exceptional promise and innovation in mathematical research.

    Other Important Prizes in Mathematics:

    • Fields Medal: Awarded every four years to mathematicians under 40, the Fields Medal is the most prestigious global mathematics award, established in 1936, and presented by the International Mathematical Union to recognize outstanding contributions to the field.
    • Abel Prize: Instituted by the King of Norway in 2001, the Abel Prize is an annual international award recognizing lifetime achievement in mathematics, often considered the closest equivalent to the Nobel Prize in the discipline.
    • Wolf Prize in Mathematics: Awarded annually since 1978 by the Wolf Foundation in Israel, the Wolf Prize honours exceptional achievements across all branches of mathematics and is ranked just below the Fields and Abel Prizes in prestige.
    [UPSC 2016] A recent movie titled The Man Who Knew Infinity is based on the biography of

    Options: (a) S. Ramanujan* (b) S. Chandhrashekhar (c) S. N. Bose (d) C. V. Raman

     

  • What is the potential of Biochar?

    As India gears up to launch its carbon market in 2026, biochar, a carbon-rich material made from agricultural and organic waste, is gaining attention as a sustainable solution for carbon capture and waste management. Despite its immense potential, biochar remains underutilised due to lack of policy support, market structures and awareness.

    What is the potential of biochar?

    What is Biochar and Why is it Important?

    • Biochar is a type of charcoal/black carbon produced by heating organic waste (like crop residue or solid municipal waste) in a low-oxygen environment.
    • It locks carbon into the soil for hundreds of years, reducing greenhouse gases and improving soil quality.
    • It is an effective long-term carbon sink.

    Biochar Potential in India:

    • India generates over 600 million tonnes of agricultural waste and 60 million tonnes of municipal waste each year, much of which is burned or dumped, contributing to pollution.
    • By converting just 30–50% of this waste into biochar, India could:
      • Produce 15–26 million tonnes of biochar
      • Remove 0.1 gigatonnes of Carbon Dioxide (CO₂) equivalent emissions annually
    • Biochar production also provides with the following:
      • Syngas (20–30 million tonnes) which can generate 8–13 TWh of electricity, replacing about 0.5–0.7 million tonnes of coal
      • Bio-oil (24–40 million tonnes) which can offset 12–19 million tonnes of diesel/kerosene, reducing oil imports and fossil fuel emissions by more than 2%

    Applications of Biochar in Key Sectors:

    1. Agriculture: It improves soil health and water retention, especially in semi-arid and nutrient-poor regions. It can reduce nitrous oxide emissions by 30–50%, which is vital as this gas has 273x more warming potential than CO₂. Its application leads to higher crop yields (10–25%) and reduced fertilizer needs (by 10–20%). Biochar can also enhance soil organic carbon, helping restore degraded soils.
    2. Construction: Adding just 2–5% biochar in concrete improves strength and heat resistance. It helps capture 115 kg of CO₂ per cubic metre of concrete, turning buildings into carbon sinks.
    3. Wastewater Treatment: One kg of biochar can help treat 200–500 litres of wastewater. India’s untreated wastewater (~72%) could use 2.5–6.3 million tonnes of biochar annually.
    4. Carbon Capture: Biochar can be modified to absorb CO₂ from industrial exhausts, though current efficiency is lower than traditional methods.
    5. Circular Economy: Biochar aligns with the circular economy model, waste to wealth.

    Why is Biochar Still Not Widely Adopted?

    1. It remains underrepresented in carbon credit systems due to the absence of standardised feedstock markets and consistent carbon accounting methods, which undermine investor confidence.
    2. Limited policy support, low public awareness, and no coordinated action across sectors.
    3. No strong carbon credit mechanism to reward users and producers.

    Steps that can be undertaken for Large-Scale Adoption of Biochar:

    1. R&D Support: Develop region-specific feedstock guidelines and technologies.
    2. Policy Integration: Link biochar with Crop residue management schemes, Bioenergy programs and State Action Plans on Climate Change
    3. Carbon Market Recognition: Allow biochar to earn carbon credits, giving financial incentives to farmers and investors.
    4. Village-Level Deployment: Establish small-scale biochar units that can create over 5 lakh rural jobs.
    5. Linkage with National Missions: Can be linked with Mission LiFE and the Swachh Bharat Abhiyan.

    Biochar offers a powerful tool for India’s climate smart and sustainable agriculture by enhancing soil health, improving water and nutrient retention, and bolstering climate resilience. Its integration can reduce dependency on synthetic inputs, aligning with organic farming principles. Crucially, biochar provides a significant mechanism for carbon sequestration and mitigating greenhouse gas emissions from agriculture, contributing to India’s climate goals. Leveraging this “black gold” through targeted policy support and research is essential for a greener, more resilient future.

    Practice UPSC Mains Question

    1. Biochar is emerging as a multipurpose tool for sustainable development in India. Discuss its potential across sectors and the challenges in its adoption.
    2. What are the salient features of ‘Waste-to-Energy’ policy of India? Describe the role of waste to energy technologies in achieving energy security in India.
  • Microplastic and marine debris levels

    Microplastic Pollution:

    Microplastics are now a serious environmental and health threat. A recent (Ministry of Earth Sciences) MoES–NCCR survey found alarming levels along India’s east and west coasts, highlighting the urgent need to embed microplastic control within India’s environmental governance framework.

    Key Findings from NCCR Survey (2022–2025):

    1. Major microplastic sources identified:
      1. Riverine inputs (plastic waste transported by rivers)
      2. Abandoned, Lost, and Discarded Fishing Gear (ALDFG), a persistent marine debris source globally
    2. The presence of primary (e.g., microbeads in cosmetics) and secondary microplastics (from the breakdown of plastic waste) was confirmed.

    Microplastics: Nature

    • Definition: Plastic particles ranging between 1 micrometre (µm) and 5 millimetres (mm).
    • Types:
      • Primary Microplastics: Manufactured in small sizes (e.g., microbeads in personal care products).
      • Secondary Microplastics: Result from degradation of larger plastic items due to sunlight, wave action and other environmental factors.

    Environmental Impact of Microplastics:

    Impact on Marine Environments:

    1. Ingestion by Marine Life: Marine organisms, including fish, seabirds, ingest microplastics and can cause physical harm including gut blockages and tissue damage.
    2. Bioaccumulation in Marine Food Webs: Bioaccumulation can lead to higher concentrations of toxins such as Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs) in top predators, potentially impacting their health and reproductive success.
    3. Habitat Disruption: Microplastics can accumulate in marine sediments and affect the structure and function of marine ecosystems.
    4. Chemical Leaching: Microplastics can leach harmful chemicals into the surrounding seawater. These chemicals include Bisphenol A (BPA), which is known to cause reproductive defects in some fish species, along with phthalates and brominated flame retardants, all of which can interfere with the endocrine system.

    Impact on Ecological Systems:

    1. Soil Contamination: Microplastics can negatively impact soil structure, microbial activity, and nutrient cycling, affecting plant growth and overall ecosystem health. They can act as carriers for toxins like heavy metals (e.g., Lead (Pb) and Cadmium (Cd)).
    2. Disruption of Food Webs: Microplastics can accumulate in the bodies of various organisms, potentially disrupting food chains and affecting higher trophic levels.
    3. Impact on Soil Biota: Exposure to microplastics can negatively impact soil-dwelling organisms like earthworms and microorganisms, affecting their growth and reproduction. Leaching of plastic additives such as phthalates can disrupt cell membrane function in microbes.
    4. Plant Toxicity: Microplastics can be absorbed by plants, potentially affecting their growth and development, and introducing toxins into the food chain.

    India’s Initiatives on Microplastic Management

    1. Plastic Waste Management Rules, 2016 (Amended 2021–22): Ban on single-use plastics and Emphasis on Extended Producer Responsibility (EPR) for collection and recycling.
    2. Swachh Bharat Mission 2.0: Includes solid waste segregation, treatment, and scientific disposal.
    3. Ecosensitive Coastal Zone Regulation (CRZ): CRZ rules govern development along coastlines and indirectly reduce marine plastic input.
    4. FSSAI Project: Ongoing study to develop standard detection protocols for microplastics in food products.

    International Conventions and Agreements

    • MARPOL (International Convention for the Prevention of Pollution from Ships) Annex V prohibits the discharge of plastics and synthetic fishing gear into the sea.
    • Basel Convention (1989, amended in 2019) regulates transboundary movement of plastic waste. India ratified the amendments concerning plastic waste in 2020.
    • The United Nations Environment Assembly (UNEA) adopted a historic resolution to negotiate a legally binding global treaty on plastic pollution by 2024 (still ongoing).
    • Sustainable Development Goal 14 talks about Preventing and significantly reducing marine pollution of all kinds, particularly from land-based activities.
    • Global Partnership on Marine Litter (GPML): A UN Environment initiative, India is a participating country.

    Way Forward

    1. National Microplastic Monitoring Programme: Expand surveys to include rivers, lakes, groundwater, and terrestrial ecosystems.
    2. Ban on Microbeads: A clear legislative ban on the use of microbeads in personal care products (done in countries like the UK and USA).
    3. Fishing Gear Recovery Programmes: Introduce buy-back schemes or incentives for collection of damaged fishing gear.
    4. Invest in R&D: Support startups and research institutes working on biodegradable alternatives and plastic detection methods.
    5. Public Awareness and Behavioural Change: Use platforms like Eco Clubs, MyGov, Swachh Bharat campaigns for mass education.

    The presence of microplastics disrupts ecosystems by affecting organisms’ behavior and physiology, impacting soil fertility, and altering aquatic food webs. Addressing microplastic pollution requires a multi-faceted approach, including reducing plastic consumption, improving waste management, and developing innovative solutions like biodegradable alternatives and advanced filtration systems.

    Practice UPSC Mains Questions:

    1. What are microplastics and how do they impact human health and the environment? Evaluate India’s current policy response to the problem and suggest a comprehensive mitigation strategy.
    2. Critically discuss the effectiveness of current national and global efforts to combat microplastic pollution, including initiatives like the Single-Use Plastic ban and the ongoing discussions around a legally binding international plastics treaty.
  • In News: Great Barrier Reef

    Why in the News?

    The Great Barrier Reef is facing its sharpest coral decline in 40 years, with the 2024 mass bleaching—driven by climate change, cyclones, and coral predators—severely damaging large reef areas.

    In News: Great Barrier Reef

    About Great Barrier Reef:

    • Location: Coral Sea, off the northeast coast of Queensland, Australia.
    • Length & Area: Extends ~2,300 km; comprises ~3,000 reefs and 900 islands, covering ~350,000 square kilometers (about 10% of global coral reef ecosystems).
    • Biodiversity:
      • Hosts 400 coral species, 1,500 fish species, and 4,000 mollusk species.
      • Habitat for endangered species like the dugong and green turtle.
    • Reef Types: Includes platform reefs, wall reefs, and fringing reefs.
    • Protection Status:
      • Managed by the Great Barrier Reef Marine Park Authority.
      • Declared a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site in 1981.
    • Mass Bleaching Years: Notable events occurred in 1998, 2002, 2016, 2017, 2020, 2022, 2024, and 2025.

    Coral Decline and Bleaching Events:

    • Main Cause: Heat stress due to climate change, particularly during marine heatwaves.
    • 2024 Event: Fifth major bleaching since 2016; had the widest spatial impact recorded in the Australian Institute of Marine Science’s 39-year monitoring program.
    • Additional Damage: Cyclones (e.g., Cyclone Jasper) and flood plumes caused physical damage and freshwater stress.
    • Biological Threats: Crown-of-thorns starfish (COTS) outbreaks intensified coral predation, especially in the Swains sector.
    • 2025 Survey Findings:
      • 48% of 124 surveyed reefs showed coral decline.
      • Only 10% recorded an increase in coral cover.
    • Regional Impact: Southern Great Barrier Reef saw a 30.6% drop in hard coral cover—the sharpest annual decline ever recorded in that zone.
    [UPSC 2014] The scientific view is that the increase in global temperature should not exceed 2 0 C above pre-industrial level. If the global temperature increases beyond 30 C above the pre-industrial level, what can be its possible impact/impacts on the world?

    1. Terrestrial biosphere tends toward a net carbon source. 2. Widespread coral mortality will occur. 3. All the global wetlands will permanently disappear.  4. Cultivation of cereals will not be possible anywhere in the world. Select the correct answer using the code given below:

    Options: (a) 1 only (b) 1 and 2 only* (c) 2, 3 and 4 only (d) 1, 2, 3 and 4 only

     

  • Bacterial cause behind Mass Starfish Deaths

    Why in the News?

    Since 2013, over 5 billion starfish have died along North America’s Pacific coast due to a wasting disease now linked to Vibrio pectenicida, a cholera-related bacterium.

    Bacterial cause behind Mass Starfish Deaths

    About Starfish (Sea Stars):

    • Taxonomy: Belong to phylum Echinodermata; exclusively marine organisms.
    • Species: Brisingida, Forcipulatida, Velatida, Valvatida, Spinuloside
    • Body Structure:
      • Radial symmetry (adults), bilateral symmetry (larvae)
      • Calcareous exoskeleton for protection
      • Water vascular system for respiration and circulation
    • Unique Features:
      • Regeneration: Can regrow lost limbs
      • No blood or brain: Seawater circulates nutrients
      • Eyespots: At arm tips, help sense light
      • Tough skin: Made of calcium carbonate
    • Feeding: Carnivorous, detritivorous, and scavengers

    Reasons for Mass Deaths (2013–2025):

    • Causal Agent: Identified in 2025 as Vibrio pectenicida, a bacterium related to cholera-causing strains.
    • Symptoms: Limb detachment; Tissue disintegration; Melting into a pile of gunk.
    • Most Affected Species: Sunflower sea stars, which saw a 90% population decline.
    • Geographical Spread: Along the Pacific coast from Alaska to Mexico.
    • Ecological Consequences:
      • Starfish are keystone predators, especially of sea urchins.
      • Their decline led to urchin population explosions, which overgrazed kelp forests.
      • Resulted in biodiversity loss and reduced carbon sequestration.
    [UPSC 2012] Vultures which used to be very common in Indian countryside some years ago are rarely seen nowadays. This is attributed to:

    (a) the destruction of their nesting sites by new invasive species disease among them (b) a drug used by cattle owners for treating their diseased cattle persistent and fatal (c) scarcity of food available to them (d) a widespread, persistent and fatal disease among them