🆚 In situ vs Ex situ (what to choose?)
Big Idea: Most real conservation uses both approaches. In situ protects ecosystems long-term, while ex situ prevents extinction when the wild is too risky.
In situ
- In the natural habitat
- Protects ecosystems and many species
- Keeps natural behaviours and interactions
- Best long-term if threats can be reduced
Ex situ
- Outside the natural habitat
- Emergency protection for very threatened species
- Supports breeding and genetic storage
- Needs reintroduction and habitat repair
📝 Decision checklist: choosing the best strategy
Use this checklist to justify your choice in evaluation questions.
- Urgency of extinction risk (very high → ex situ backup)
- Habitat condition (intact vs degraded)
- Threat controllability (poaching, invasives, pollution)
- Available space for a viable population
- Genetic diversity potential
- Cost and long-term management capacity
- Local community support and fairness
High marks = name a strategy and justify it using 2–3 checklist points.
Get feedback like a real examiner
Submit your answers and get instant feedback — what you did well, what's missing, and exactly what to write to score full marks.
🤝 The strongest strategy is usually a mix
IB examiners reward answers that recognise no single strategy is perfect.
- Step 1: Reduce threats in the wild (laws, enforcement)
- Step 2: Protect and restore habitat (in situ)
- Step 3: Create an ex situ safety net (breeding / seed bank)
- Step 4: Reintroduce and monitor populations
Ex situ alone saves species short-term, but cannot replace habitat protection.
🏆 Exam tips: in situ vs ex situ questions
9-mark structure: Top answers include comparison + evaluation + justified conclusion.
- 1. Define both strategies briefly
- 2. Compare effectiveness (ecosystems vs emergency rescue)
- 3. Evaluate limitations of each
- 4. Apply to context (habitat quality, threat level)
- 5. Conclude with judgement (often a combined strategy)
Learn what examiners really want
See exactly what to write to score full marks. Our AI shows you model answers and the key phrases examiners look for.
IB-style question — Compare in situ vs ex situ — one advantage each
The Daintree Lowland Rainforest Reserve (Australia) protects the southern cassowary in situ. The Cairns Wildlife Dome holds cassowaries in captivity for breeding and public education. State one advantage of the in situ approach and one advantage of the ex situ approach for conserving the southern cassowary. [2]
How to answer it, step by step
- In situ advantage
• Protects the whole ecosystem — the cassowary's seed-dispersal role, food web interactions, and natural behaviours are all maintained, benefiting hundreds of co-dependent rainforest species. - Ex situ advantage
• Captive breeding provides a safe insurance population: if a disease or cyclone devastates the wild population, captive stock prevents total extinction and individuals can be reintroduced.
Final answer
Award 1 mark per distinct, valid advantage with a mechanism. Accept any well-reasoned alternative: in situ — natural behaviour preserved / genetic diversity of whole wild population / cheaper at landscape scale / ethically acceptable. Ex situ — controlled conditions prevent predation / specialist veterinary care / genetic management / public education funds conservation. Both marks require a reason beyond just naming the strategy.
IB-style question — EVS and conservation choices [9-mark essay]
Explain how ecocentric, anthropocentric, and technocentric environmental value systems (EVS) lead to different choices between in situ and ex situ conservation strategies, using named examples. [9]
How to answer it, step by step
- Define each EVS and its core stance (name all three)
• Ecocentric: nature has intrinsic value independent of human use; non-human species have rights; humans should minimise interference.
• Anthropocentric (soft): nature has value because it serves humans — sustainably managed for ecosystem services, food, wellbeing; humans are stewards.
• Technocentric / cornucopian: human technology and management can solve environmental problems; nature is a resource; science-based solutions are preferred. - Link each EVS to preferred conservation strategy + named example
• Ecocentric → strongly favours in situ. National parks, biosphere reserves, and rewilding let ecosystems self-regulate. Example: the Białowieża Forest biosphere reserve (Poland/Belarus) protects primeval forest with minimal human management. Ecocentrics oppose zoos — keeping animals captive denies their biorights.
• Anthropocentric → pragmatic mix, leaning in situ for ecosystem services. Protected areas (e.g. Costa Rica's national parks) are justified because they supply clean water, carbon sequestration, and ecotourism revenue. Ex situ (e.g. seed banks such as the Svalbard Global Seed Vault) is also accepted because it protects future crop genetic diversity — a direct human benefit.
• Technocentric → favours ex situ and high-tech solutions. Zoos with captive breeding (e.g. Frozen Ark Project, UK — cryopreservation of genetic material from 5,000+ species), gene banks, and de-extinction biotechnology are preferred. Nature can be 'fixed' by science; designating vast land as off-limits to development is seen as unnecessary. - Evaluate each approach's strengths and limits
• In situ (ecocentric): most cost-effective at ecosystem scale; maintains all species and processes; BUT requires large intact habitat that may conflict with land-use needs in developing nations.
• Anthropocentric mix: politically feasible because it aligns conservation with economic interest (ecotourism, payments for ecosystem services); BUT can lead to 'greenwashing' if economic value drives decisions rather than biodiversity.
• Ex situ (technocentric): saves critically endangered species when habitat is already destroyed; Sumatran rhino captive programme preserved genetics before wild extinction; BUT small gene pools risk inbreeding; released animals may not survive; cannot restore ecological function. - Conclusion — supported value judgement
• In practice, no single EVS produces a complete conservation solution. Ecocentric in situ strategies are ecologically superior but require political will and land availability. Technocentric ex situ approaches are a critical last resort when habitat loss is irreversible. The most effective real-world programmes (e.g. New Zealand kākāpō recovery) combine in situ sanctuary management with ex situ captive breeding — suggesting that conservation success depends less on which EVS dominates and more on integrating multiple strategies according to context.
Final answer
Markband 7–9: names and defines all three EVS precisely; links each to specific named in situ AND ex situ strategies with real examples; balanced evaluation including both strengths and limits of each approach; explicit, evidence-supported conclusion that makes a value judgement. Markband 4–6: some EVS types linked to strategies, limited named examples, some analysis. Markband 1–3: only one EVS addressed, or strategies described without linking to EVS, or no conclusion. Key examiner pitfall: listing strategies without ever naming the EVS = max 4. Listing EVS without linking to specific strategies = max 4.
HL. HL.c (ethics): HL students should engage with the concept of biorights (Naess, deep ecology) when discussing ecocentric objections to ex situ conservation, and may reference the 1992 Convention on Biological Diversity as an anthropocentric/intergovernmental framework. The tension between intrinsic value and instrumental value is a core HL ethics theme.