PIB TrackerForty years of ocean surveys become one national report
CMLRE's report on deep-sea and distant-water fishery resources maps India's 2.37 million sq km EEZ — including the mesopelagic 'twilight zone' that drives the biological carbon pump.
What happened
- The report covers India's 2.37 million sq km Exclusive Economic Zone.
- It draws on over 400 oceanographic cruises aboard FORV Sagar Sampada.
- The mesopelagic 'twilight zone' runs from 200 to 1,000 metres.
- Vertical migration there drives the ocean's biological carbon pump.
- Hotspots include Kollam Bank, Angria Bank and the terrace off Trivandrum.
For Prelims
- CMLRE: the Centre for Marine Living Resources & Ecology, under the Ministry of Earth Sciences, Kochi — marking its silver jubilee.
- EEZ: the Exclusive Economic Zone extends 200 nautical miles from the baseline; India's is about 2.37 million sq km.
- FORV Sagar Sampada: the Fishery and Oceanographic Research Vessel used for the surveys.
- Mesopelagic zone: 200-1,000 m deep — the 'twilight zone', dominated by myctophids (lanternfishes).
- Biological carbon pump: the transfer of carbon from surface waters to the deep ocean, driven partly by diel vertical migration.
- Demersal: living on or near the sea floor, as against pelagic (open water).
- Banks named: Kollam Bank, Angria Bank, the off-Mangalore slope and the terrace off Trivandrum.
- Commitments: SDG 14 (Life Below Water) and the UN Decade of Ocean Science for Sustainable Development.
For UPSC: The clearest statement of the blue economy's central trade-off — the same deep-sea biomass is a fishery resource and a carbon regulation mechanism. Use it for marine biodiversity, the blue economy, EEZ resources and SDG 14.
What it is NOT: Identifying underexploited stocks is not a licence to harvest them — the mesopelagic community the report maps is also the machinery of the biological carbon pump.
For Mains
Syllabus: GS3.14 · GS3.4 · Linkage L2
Anchor
The deep ocean is where resource assessment and climate regulation are the same inventory counted twice — the twilight zone is both fishery and carbon pump.
Substantiation (data)
Nearly four decades of research and over 400 cruises across a 2.37 million sq km EEZ, mapping the 200-1,000 m mesopelagic layer and underexploited demersal stocks beyond 200 m.
Exemplification
Kollam Bank, Angria Bank and the Trivandrum terrace are documented as nurseries and vulnerable ecosystems rather than simply as fishing grounds.
Problematisation
Myctophid stocks are large enough to attract industrial harvesting; removing them would degrade the vertical carbon transfer that regulates climate.
Way-forward
Use the report's eDNA, acoustics and ecosystem modelling base to set marine spatial plans before deep-sea fishing capacity is licensed.
Position
India should treat the twilight zone as climate infrastructure first and as a fishery second.
Deploys into: Conservation + fisheries (GS3.14, GS3.4) · blue economy, EEZ resources, marine spatial planning and SDG 14.
Ministry of Earth Sciences · 2026-08-20 · PRID 2301667 · PIB source ↗