Conservation strategies must not only maintain current population numbers but also build resilience — the capacity of species to withstand and recover from future threats, particularly environmental change.
Definition: Legally designated areas where human activities are regulated to protect biodiversity and ecosystem function.
Types in Australia:
- National Parks (no extractive use)
- Nature Reserves
- Marine Protected Areas (MPAs)
- State Forests with conservation zones
- Indigenous Protected Areas (IPAs) — managed by Traditional Owners
Effectiveness:
- Well-enforced protected areas significantly reduce extinction risk
- Size matters: larger reserves support more species and provide buffer against edge effects
- SLOSS debate (Single Large Or Several Small): larger reserves generally preferable, but multiple smaller reserves can protect more total species if each covers different communities
Limitations:
- Climate change may shift species ranges outside reserve boundaries
- Many reserves are too small to maintain viable populations
- Under-resourced enforcement in many countries
Wildlife corridors are strips of habitat connecting otherwise isolated patches, enabling:
- Gene flow between populations (reducing inbreeding)
- Recolonisation after local extinction
- Range shifts in response to climate change
- Movement of large animals with large home ranges
Examples:
- Habitat links along creek lines (riparian corridors)
- Revegetated ‘habitat bridges’ over roads (fauna overpasses)
- Marine connectivity zones between reef systems
Limitations: Corridors can also facilitate spread of disease, fire and invasive species.
Definition: The deliberate movement of individuals from one location to another for conservation purposes.
Types:
- Reinforcement: Adding individuals to an existing population to boost numbers or genetic diversity
- Reintroduction: Re-establishing a species to part of its former range from which it had been lost
- Assisted migration (controversial): Moving species to predicted future suitable habitat
Key considerations: Source population genetics, disease screening, predator exclusion at destination, habitat suitability, community engagement.
Example: Eastern barred bandicoot (Perameles gunnii) — predator-free fenced areas and offshore islands used as managed translocation sites.
Process:
1. Collect founding individuals from wild (minimising impact)
2. Establish captive colony with genetic management to maintain diversity
3. Breed animals using studbook and genetic matching
4. Prepare animals for reintroduction (reduce human imprinting, train predator avoidance)
5. Release into secured wild habitat; monitor survival
Examples:
- Melbourne Zoo: eastern barred bandicoot, Tasmanian devil (insurance population), helmeted honeyeater
- Lord Howe Island stick insect: captive colony at Melbourne Zoo awaiting island rodent eradication
Limitations: Expensive; genetic adaptation to captivity; limited capacity (most zoos hold <1,000 individuals per species); success depends on threat removal in wild.
Purpose: Preserve genetic material for threatened species, especially those at high extinction risk.
Types:
- Seed banks: Dried seeds stored at –20°C (Svalbard Global Seed Vault; Australian PlantBank)
- Frozen tissue/DNA banks: Cells cryopreserved in liquid nitrogen
- Cryobanks for vertebrates: Sperm, eggs, embryos of mammals, fish, amphibians
- Herbarium specimens: Voucher specimens with associated DNA
Value:
- Insurance against extinction
- Future restoration using genetic material from extinct wild populations
- Research material for genetics, taxonomy, ecology
Australian example: Frozen Ark (held at multiple institutions) stores DNA and cells from threatened species globally.
Problem: Broad-spectrum pesticides (insecticides, herbicides, rodenticides) kill non-target species:
- Neonicotinoid insecticides impair bee navigation and reproduction
- Second-generation anticoagulant rodenticides (SGARs) kill raptors and marsupials via secondary poisoning
- Herbicides reduce weed diversity that supports invertebrate food chains
Solutions:
- Integrated Pest Management (IPM): use biological, cultural and targeted chemical controls to reduce overall pesticide volume
- Targeted application: apply only where pests are present; avoid buffer zones near water and vegetation
- Bait stations: reduce non-target exposure compared to broadcast baiting
- Seasonal restrictions: avoid applying during breeding seasons of sensitive species
- Alternative chemicals: use compounds that are rapidly degraded and less persistent
EXAM TIP: VCAA questions on this topic often ask you to explain how a specific strategy addresses a specific threat. Always match strategy to threat — e.g. ‘captive breeding addresses the risk of extinction from small population size and stochastic events by maintaining an insurance population outside the threatened habitat’.
