Why is "Missing upwelling as nutrient source" a common mistake in The Antarctic Ecosystem Part 2?

Why it happens: Not a familiar process. How to avoid it: Antarctic productivity is driven by UPWELLING — deep water brings nutrients up. Mention it explicitly. Source: 0460 Examiner Reports 2022-2024

Why is "Stating energy flow without 10% rule" a common mistake in The Antarctic Ecosystem Part 2?

Why it happens: Numbers feel pedantic. How to avoid it: 10% rule is mark-scheme gold. Always state when discussing energy flow.

Changing EcosystemsCambridge IGCSE Geography (0460)

The Antarctic Ecosystem Part 2

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Antarctic Ecosystem Part 2 Study Notes — Cambridge IGCSE Geography 0460 (2024-2026 syllabus)

Antarctic Circumpolar Current. Upwelling. Krill seasonal cycles tied to sea ice. Energy flow through the ecosystem.

What you’ll learn

Mapped to the Cambridge IGCSE 0460 syllabus (2024-2026).

3.2.1 — Describe Antarctic Circumpolar Current.
3.2.2 — Explain seasonal krill cycle.
3.2.3 — Apply 10% energy rule.

Antarctic Circumpolar Current

Strongest ocean current — isolates Antarctica + drives upwelling.

World's strongest ocean current by volume (~150 Sverdrups). Flows eastward, completely circling Antarctica.

Two key effects.

Isolation. Prevents warmer waters from reaching Antarctica, maintaining cold conditions.
Upwelling. Cold deep water rises, bringing nutrients (nitrates, phosphates, iron) to the surface. Fuels massive phytoplankton blooms.

Without upwelling. Antarctic surface waters would be nutrient-poor. The ecosystem depends on this circulation.

Cambridge tip. Mark scheme rewards mentioning BOTH effects: isolation AND upwelling.

Strongest current by volume.
Isolates Antarctica from warmer waters.
Drives nutrient-rich upwelling.

See the full worked example for the antarctic ecosystem part 2 →

Krill seasonal cycle

Summer bloom; winter sea-ice refuge.

Summer. 24-hour sunlight + upwelled nutrients → MASSIVE phytoplankton bloom. Krill populations EXPLODE — densities up to 30 kg/m³.

Winter. Larvae shelter under SEA ICE and feed on ICE ALGAE (algae growing on the underside). Sea ice is essential.

Climate-change vulnerability. Shrinking sea ice = less algae for larvae = krill decline. Already documented near Antarctic Peninsula.

Cambridge tip. Mark scheme rewards explicit mention of SEA-ICE dependence + climate change.

Summer: bloom and explosion.
Winter: shelter under sea ice + ice algae.
Climate change threatens via sea-ice loss.

See the full worked example for the antarctic ecosystem part 2 →

Energy flow

10% rule — top predators rare by necessity.

Energy enters the ecosystem from the SUN, captured by PHYTOPLANKTON. Passes up the trophic levels:

Sun → Phytoplankton → Krill → Fish/Seals/Penguins → Whales/Orcas

10% rule. Only ~10% of energy at one level becomes biomass at the next. 90% lost as HEAT, RESPIRATION, WASTE.

Implication. Each higher level supports fewer individuals. Top predators (orcas, killer whales) are rare by mathematical necessity.

Cambridge tip. State the 10% rule explicitly. Mark scheme awards a separate mark for it.

10% energy passes up each trophic level.
Heat, respiration, waste = 90% loss.
Top predators rare by necessity.

See the full worked example for the antarctic ecosystem part 2 →

How it’s examined

Antarctic dynamics appear on most Paper 1s. Most-tested: Circumpolar Current (5 marks), 10% rule (4-5 marks).

Sources: Cambridge IGCSE Geography 0460 syllabus (2024-2026); 0460 Examiner Reports 2022-2024; 0460/22 Oct/Nov 2024 question paper and mark scheme. Last reviewed 2026-05-09.

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Step-by-step worked examples — The Antarctic Ecosystem Part 2

Step-by-step solutions to past-paper-style questions on the antarctic ecosystem part 2, written exactly the way a tutor would explain them at the board.

1Antarctic Circumpolar Current (5 marks)
Extended• Adapted from 0460/22 Oct/Nov 2024• currents
Question
Describe the Antarctic Circumpolar Current and explain its importance to the ecosystem. (5 marks)
Step-by-step solution
1. Step 1
  Circumpolar Current (2 marks). Eastward-flowing ocean current that circles Antarctica continuously. World's strongest current by volume (~150 Sverdrups). Isolates Antarctic waters from warmer northern oceans.
2. Step 2
  Cold isolation (1 mark). Prevents warmer waters from reaching Antarctica, maintaining cold conditions.
3. Step 3
  Nutrient upwelling (2 marks). Current causes UPWELLING — deep cold water rises, bringing nutrients (nitrates, phosphates, iron) to the surface. Fuels phytoplankton blooms. Foundation of the ecosystem.
Answer
Circumpolar Current isolates Antarctica (keeping it cold) AND drives upwelling that brings nutrients to the surface, enabling rich phytoplankton growth.
2Krill seasonal cycle (5 marks)
Extended• krill
Question
Describe how krill populations change with seasons in Antarctica. (5 marks)
Step-by-step solution
1. Step 1
  Summer bloom (2 marks). 24-hour sunlight + upwelled nutrients → massive phytoplankton bloom. Krill feed actively; populations EXPLODE. Density can exceed 30 kg/m³.
2. Step 2
  Sea-ice dependence (2 marks). Larvae shelter under sea ice and feed on ICE ALGAE (algae growing on the underside of sea ice). Sea ice is essential winter refuge.
3. Step 3
  Climate-change vulnerability (1 mark). Shrinking sea ice = less algae for larvae = krill decline. Already documented in some regions.
Answer
Summer: massive bloom; winter: shelter under sea ice; climate-change threatens via sea-ice loss.
3Energy flow in Antarctic ecosystem (5 marks)
Extended• ecosystem
Question
Describe how energy flows through the Antarctic ecosystem. State why each level supports FEWER individuals than the one below. (5 marks)
Step-by-step solution
1. Step 1
  Sun → phytoplankton (1 mark). Solar energy converted into biomass through photosynthesis.
2. Step 2
  Trophic levels (2 marks). Phytoplankton → krill → fish/seals/penguins → whales/orcas. Each level passes energy upward as biomass.
3. Step 3
  10% rule (2 marks). Only ~10% of energy is passed to the next level — rest is lost as HEAT, RESPIRATION, and WASTE. Therefore each level supports fewer individuals than the level below. This is why top predators are rare.
Answer
Sun → phytoplankton → krill → predators → top predators. ~10% energy passes up each step (rest lost as heat/respiration/waste). Top predators rare by necessity.
Examiner tip
Cambridge often tests the 10% rule. Mark scheme awards a mark for stating it explicitly.

Key Definitions and Keywords — The Antarctic Ecosystem Part 2

Definitions to memorise and the exact keywords mark schemes credit for the antarctic ecosystem part 2 answers — sharpened from recent examiner reports for the 2026 0460 sitting.

Antarctic Circumpolar Current
Examiner keyword
Eastward-flowing current circling Antarctica. World's strongest by volume. Isolates Antarctic waters and drives upwelling.
Upwelling
Examiner keyword
Deep, cold, nutrient-rich water rising to the surface. Fuels marine productivity.
Sea ice
Examiner keyword
Frozen ocean water. Forms and melts seasonally. Provides habitat for ice algae and shelter for krill larvae.
Trophic level
Examiner keyword
Position in a food chain — primary producer (1st), primary consumer (2nd), etc.
10% rule (energy flow)
Examiner keyword
Only ~10% of energy at one trophic level is converted to biomass at the next; rest lost as heat, respiration, and waste.

Common Mistakes and Misconceptions — The Antarctic Ecosystem Part 2

The traps other students keep falling into on the antarctic ecosystem part 2 questions — taken from recent Cambridge IGCSE 0460 examiner reports and mark schemes — and how to avoid them.

✕Missing upwelling as nutrient source
0460 Examiner Reports 2022-2024
Why it happens
Not a familiar process.
How to avoid it
Antarctic productivity is driven by UPWELLING — deep water brings nutrients up. Mention it explicitly.
✕Stating energy flow without 10% rule
Why it happens
Numbers feel pedantic.
How to avoid it
10% rule is mark-scheme gold. Always state when discussing energy flow.

Practice questions

Exam-style questions with step-by-step worked solutions. Try one before checking the method.

Past paper style quiz

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The Antarctic Ecosystem Part 2

Short Study Notes in the form of Slides

Detailed Study Notes

What you’ll learn

How it’s examined

1Antarctic Circumpolar Current (5 marks)

2Krill seasonal cycle (5 marks)

3Energy flow in Antarctic ecosystem (5 marks)

Antarctic Circumpolar Current

Upwelling

Sea ice

Trophic level

10% rule (energy flow)

✕Missing upwelling as nutrient source

✕Stating energy flow without 10% rule

Practice questions

Past paper style quiz

Assess your understanding