Major Fishing Grounds of the World

Why Fish Crowd Into a Few Patches of Sea

Every food chain in the sea starts with phytoplankton, microscopic drifting plants. Zooplankton eat them, small fish such as sardine and herring eat the zooplankton, and cod, tuna, seabirds and people eat the small fish. Phytoplankton need sunlight, which reaches only the top 200 metres or so, and nutrients such as nitrates and phosphates. Dead matter sinks, so the nutrients collect in the dark deep water. A sea is rich only where something lifts that water back into the light.

NCERT puts the average width of the continental shelf at about 80 km. The Siberian shelf is the widest, at up to about 1,500 km, and shelves are almost absent off Chile. Fishermen sort fish by habitat. Pelagic fish (herring, sardine, anchovy, mackerel, tuna) swim in open water. Demersal fish (cod, haddock, hake, plaice, sole) live near the bottom and are trawled, which is why shallow shelves matter so much. Biologists say plankton drift, nekton swim freely and benthos live on the floor.

Where Warm Meets Cold: Grand Banks, North Sea and Japan

Our ocean currents page lists which currents are warm and which cold. Where they meet, the cold current supplies nutrients and oxygen, and the warm one keeps the sea ice-free. Eddies along the front between them lift the nutrients into sunlit water, plankton bloom, and fish follow.

Grand Banks, off Newfoundland (Canada). These shallow submarine plateaus, mostly under 100 metres deep, are where the cold Labrador Current meets the warm Gulf Stream. They became the world's most famous cod ground. Moist air from over the Gulf Stream is chilled crossing the cold water, producing thick advection fog, most frequent in summer. The Labrador Current also carries icebergs south; one sank the Titanic south of the banks in 1912. Industrial trawling wrecked the stock. On 2 July 1992 Canada banned cod fishing, when spawning northern cod had fallen to about 1 per cent of its peak. Nearly 30,000 people in Newfoundland and Labrador lost their jobs.

North Sea and Dogger Bank. The North Sea is a shallow shelf sea, stirred by strong tides and fed by water from the warm North Atlantic Drift. The Dogger Bank, a vast sandbank between England and Denmark, is in places less than 20 metres deep. It was long a prime ground for herring, cod and plaice. Farther north, warm Atlantic water meets cold Arctic water off Norway and Iceland, which land cod, herring and capelin. Iceland fought three "Cod Wars" with Britain between 1958 and 1976 as it pushed its fishing limit out to 200 nautical miles.

North-west Pacific. The warm Kuroshio flows north past Japan and meets the cold Oyashio, coming south from the Kuril Islands, off north-east Honshu. Kuroshio means "black current", after its deep-blue water, so clear because it carries few nutrients. Oyashio means "parent current", because it nourishes the fish. The mixing zone yields sardine, saury, mackerel, squid and salmon. FAO has long ranked the north-west Pacific the most productive fishing area in the world.

Upwelling: Peru, Benguela and the El Niño Crash

On the western coasts of continents in the trade-wind belt, winds blow along the shore towards the equator. The Earth's rotation turns the surface water they drive offshore, and cold water from below rises to replace it. There are four great upwelling systems: California, Humboldt (Peru–Chile), Canary and Benguela. Together they cover roughly 1 per cent of the ocean, yet they have produced up to about a fifth of the world's marine catch.

Peru. The cold Humboldt (Peru) Current and its upwelling support the Peruvian anchoveta, in most years the largest catch of any single fish species. Most of it becomes fishmeal and fish oil for farmed fish, pigs and poultry worldwide. Peru's shelf is narrow; its riches come from upwelling.

El Niño. Every few years the trade winds weaken and warm water from the western Pacific spreads east. Peruvian fishermen named the warming El Niño, "the Christ child", because it tends to arrive around Christmas. A warm, nutrient-poor layer caps the coast, so upwelling brings up warm water instead of cold. Plankton crash, the anchoveta scatter or die, and the guano birds starve. Peru's catch hit a record of about 12 million tonnes in 1970. During the 1972–73 El Niño, with heavy overfishing on top, it fell to 1.8 million tonnes by 1973. The same event often weakens India's monsoon, as our explainer on El Niño and the monsoon shows.

The Grounds at a Glance, and Why the Tropics Lag

Why do sunny tropical seas catch less?

• Locked nutrients. A warm, light surface layer floats on cold, dense water below a permanent thermocline, and there is no winter overturning. The open tropical ocean is deep blue precisely because it holds little plankton.
• Many species, few of each. Coral reefs and mangroves are rich in variety, but one species rarely forms a shoal big enough to net, and reefs cannot be trawled.
• Narrow shelves and spoilage. Many tropical shelves are narrow, and catch rots fast in the heat.

Exceptions exist. Tuna roam the open tropical ocean, and the Indian Ocean tuna fishery shapes diplomacy, as in our article on India and Seychelles talking tuna. The Arabian Sea is productive because the summer monsoon drives upwelling off Somalia, Oman and south-west India.

India: Seas, Rivers and Ponds

India's fish now come mostly from inland waters, above all ponds stocked with the Indian major carps (catla, rohu, mrigal) and shrimp. At sea, about three-fifths of landings come from the west coast. The Arabian Sea shelf is wider, especially off Gujarat and Maharashtra, and monsoon upwelling off Kerala and Karnataka feeds the oil sardine and mackerel. The Bay of Bengal, freshened by great rivers, is strongly layered and less productive.

Schemes. The Blue Revolution scheme was approved in December 2015 with ₹3,000 crore for five years; keep it apart from the Green and White revolutions on our agriculture page. The Pradhan Mantri Matsya Sampada Yojana (PMMSY) was launched on 10 September 2020 with ₹20,050 crore over five years. PM-MKSSY, a PMMSY sub-scheme approved in February 2024 (about ₹6,000 crore), aims to formalise small fishers and widen their access to credit. The October 2026 PIB release counts 2,195 Fisheries Farmer Producer Organisations. Overfishing is the other half of the story, and India's acceptance of the WTO agreement on fisheries subsidies addresses it.

How UPSC Has Asked It: Past Papers Solved

UPSC rarely writes "fishing ground"; it asks about the currents, El Niño and sea law behind one.

Practice MCQs (with answers)

1. The Grand Banks fishing ground lies where
   1. the Gulf Stream meets the Labrador Current
   2. the Kuroshio meets the Oyashio
   3. the North Atlantic Drift meets the Canary Current
   4. the Brazil Current meets the Falkland Current
2. Peru has a narrow continental shelf yet one of the world's largest fisheries, mainly because of
   1. the warm El Niño current
   2. extensive coral reefs
   3. upwelling of cold, nutrient-rich water
   4. silt from the Amazon
3. Which of these is a demersal fish, usually trawled near the sea floor?
   1. Sardine
   2. Anchoveta
   3. Tuna
   4. Cod
4. India's uniform 61-day fishing ban off the west coast runs from
   1. 15 April to 14 June
   2. 1 June to 31 July
   3. 1 July to 31 August
   4. 15 May to 14 July
5. Consider: 1. Inland fisheries produce about three-quarters of India's fish. 2. India is the world's second-largest fish producer. 3. Kerala is India's largest fish-producing state. Which are correct?
   1. 1 only
   2. 1 and 2 only
   3. 2 and 3 only
   4. 1, 2 and 3
6. Clear, deep-blue water in the open tropical ocean usually indicates
   1. little plankton, as a permanent thermocline traps nutrients below
   2. a dense plankton bloom
   3. strong upwelling
   4. heavy river inflow
7. The Dogger Bank is in the
   1. Gulf of Mexico
   2. Sea of Japan
   3. Bering Sea
   4. North Sea
8. During a strong El Niño, off the coast of Peru
   1. trade winds strengthen and upwelling increases
   2. cold Humboldt water spreads farther north
   3. warm, nutrient-poor water caps the coast and the anchoveta catch falls
   4. sea-surface temperature falls sharply

Quick Revision