Conservation: Strategies, Ethics and Australian Case Studies

Q1 — Sample Band 6 response (7 marks), annotated

In-situ conservation protects species within their natural habitat and is the preferred approach because it preserves ecosystem function, ecological relationships, and evolutionary processes [1 — definition + justification]. Ex-situ conservation maintains populations outside their natural habitat as a safety net, typically through captive breeding, seed banks, and zoos. It is used as a last resort when in-situ options are insufficient because the population is too small, threats are too severe, or the habitat is gone [1 — definition + when appropriate].

Comparing the two strategies: (i) Cost — in-situ is less expensive per species; one protected area such as the Shark Bay World Heritage Area simultaneously shelters seagrass, dugong, loggerhead turtles and tiger sharks. Ex-situ is expensive per individual, requiring ongoing facilities and veterinary expertise [1 — cost criterion]. (ii) Ecological context — in-situ preserves entire food webs and evolutionary pressures; ex-situ saves the target species but cannot replicate its ecological context — captive corroboree frogs at Taronga Zoo survive, but their role in the alpine bog food web is absent [1 — ecological criterion with example]. (iii) Effectiveness — in-situ is more effective for protecting ecosystem biodiversity, but ex-situ is more effective for preventing imminent species extinction. The eastern barred bandicoot was saved by a combination: captive breeding (ex-situ) maintained the insurance population while predator-proof fencing (in-situ threat abatement) prepared habitat for reintroduction [1 — effectiveness criterion with named Australian example].

Neither strategy is universally superior. In-situ conservation should be the foundation because it is the only approach that sustains ecosystems rather than individual species. However, ex-situ is indispensable for species on the brink when no safe habitat remains. The most effective Australian programs — such as the bandicoot recovery — combine both [1 — context-dependent judgement]. A government that redirected all funding to one strategy would compromise its ability to respond to the full range of biodiversity threats [1 — explicit overall evaluation].

Marking criteria.

• 1 mark — Defines in-situ conservation and explains why it is preferred (ecosystem + evolutionary process preservation).
• 1 mark — Defines ex-situ conservation and states when it is most appropriate (last resort / imminent extinction / no safe habitat).
• 1 mark — Compares on cost with supporting reasoning.
• 1 mark — Compares on ecological context preserved, with a named Australian example.
• 1 mark — Compares on effectiveness and uses a named Australian example of the combined approach (e.g. eastern barred bandicoot).
• 1 mark — Makes a context-dependent judgement that rejects a single-winner ranking.
• 1 mark — Explicitly links back to the overarching goal of protecting biodiversity, not just individual species.

Q2 — Sample Band 6 response (8 marks), annotated

Classification of program components. The predator-proof fenced enclosure, fox-proof boundary gates, and open-country release are all in-situ strategies because they address threats and manage habitat within the quoll's natural landscape at Booderee National Park [1]. The semi-wild staging inside the enclosure is a transitional step between ex-situ captive management and full in-situ release; it reduces adaptation-to-captivity risk by letting quolls practise wild behaviours before full release [1].

Why Tasmania was the founder source. The eastern quoll persisted only in Tasmania after mainland extinction, so the Tasmanian population effectively served as an unintentional reserve or "insurance" population [1]. This demonstrates that geographic isolation (an island) can maintain a species even when mainland threats are unsurvivable, and that such populations can later seed mainland reintroduction once threats are reduced [1].

Two key threats. First, foxes — quolls outside the fence are exposed to fox predation; foxes persist in surrounding landscapes and caused the original mainland extinction, so they limit the area where quolls can survive without intensive management [1]. Second, feral cats — recorded within 2 km of the release site; cats hunt similarly-sized prey and can prey on or compete with quolls. Together these predators confine the program to a fenced enclave rather than a landscape-scale recovery [1].

Evaluation. The program is promising but incomplete. Thirty-five individuals in an enclosure and twelve beyond the fence do not constitute a self-sustaining wild population [1]. The recommendation is to expand landscape-scale predator control (baiting and trapping) beyond the park boundary to create a larger low-predator refuge, and to monitor founder genetics so captive-derived inbreeding does not reduce fitness. Only sustained predator reduction will let the program match the eastern barred bandicoot's success [1].

Marking criteria.

• 1 mark — Correctly classifies fencing/gating/release as in-situ.
• 1 mark — Explains the semi-wild staging as a risk-reduction step bridging captive and in-situ management.
• 1 mark — Explains why Tasmania was the source population and links it to the insurance-population concept.
• 1 mark — Makes the insight explicit that geographic isolation can act as unintentional ex-situ conservation.
• 1 mark — Identifies foxes as a limiting threat with mechanism.
• 1 mark — Identifies feral cats as a second limiting threat and explains why proximity matters.
• 1 mark — Makes a data-based evaluative judgement that the program is not yet fully successful.
• 1 mark — Provides a justified, specific recommendation for the next step.

Q3 — Sample Band 6 response (6 marks)

The claim is partly defensible but largely flawed. [1 — evaluative judgement]

What is defensible: Captive breeding can prevent imminent extinction when in-situ options are insufficient — for example, the corroboree frog captive breeding program maintained an insurance population when chytrid fungus made wild survival impossible [1 — concedes the valid element with evidence].

What is wrong:

• "Always saves species." Captive breeding does not guarantee survival: it carries risks including adaptation to captivity, genetic drift, and disease in crowded facilities, and it fails if no suitable reintroduction habitat ever becomes available [1 — refutes "always"].
• "Completely reliable in the long term." Ex-situ conservation is expensive and depends on continued funding. The eastern barred bandicoot did not recover through captive breeding alone — it required predator-proof fencing and predator control (in-situ threat abatement) before wild populations could be re-established [1 — refutes reliability with evidence].
• "Redirect all funding from national parks." National parks protect whole ecosystems and hundreds of species at far lower cost per species. Redirecting all funding to zoos would leave habitats unprotected, eliminating the ecosystems any reintroduced species needs to survive [1 — refutes the redirection proposal].

Defensible reformulation: "Captive breeding is an essential safety-net strategy for species on the brink of extinction when in-situ options are insufficient, but it is most effective when combined with in-situ threat abatement and habitat protection. Neither in-situ nor ex-situ conservation alone is sufficient for most threatened species; funding should be allocated to each based on the specific threat profile and conservation status of the target species." [1 — defensible reformulation integrating both strategies]

Marking criteria.

• 1 mark — States an overall evaluative judgement.
• 1 mark — Defends the one valid element with an Australian example.
• 1 mark — Refutes "always saves species" by identifying specific risks of ex-situ conservation.
• 1 mark — Refutes "completely reliable in the long term" with the bandicoot example.
• 1 mark — Refutes the funding redirection argument (ecosystem protection is a prerequisite for reintroduction).
• 1 mark — Reformulates the claim into a defensible integrated statement.