Quick questions on In-situ and ex-situ conservation (protected areas, corridors, captive breeding, seed banks): VCE Environmental Science Unit 3

In-situ conservation protects species within their natural habitat, conserving whole ecosystems and the ecological processes that sustain them.

Ex-situ conservation protects species outside their natural habitat, usually as a last resort or as a safeguard.

VCAA questions often supply a case study (a threatened fish, bird or plant) and ask you to describe an action, explain how it conserves the species, or compare strategies. Strong answers always do three things: classify the strategy correctly as in-situ or ex-situ, link it to the specific biology of the species (its breeding, feeding, dispersal or habitat needs), and where the command term is "evaluate" or "discuss", weigh a genuine strength against a genuine limitation. For example, a seed bank protects genetic material cheaply and indefinitely, but stored seed does nothing for the wild ecosystem until it is grown out and planted into restored habitat, which is why seed banks and revegetation corridors are described together.

National parks, nature reserves and marine protected areas restrict damaging activities such as clearing, grazing and fishing. Kakadu National Park and the Great Barrier Reef Marine Park protect large functioning ecosystems. Indigenous Protected Areas, managed by Traditional Owners, now make up a large share of Australia's conservation estate and combine modern science with cultural land management such as patch burning.

Strips of habitat that reconnect fragmented patches allow animals to move, find mates, and recolonise after disturbances. They restore gene flow and reduce the isolation caused by fragmentation. Victoria's Habitat 141 and large revegetation corridors aim to link remnant vegetation across the landscape.

Species stay in their natural environment, continue to evolve under natural selection, and whole communities and ecosystem services are conserved together. It is usually cheaper per species than captive programs.

Protected areas can still suffer from invasive species, fire, pollution and climate change crossing their boundaries. Small or isolated reserves may not hold a population large enough to stay genetically healthy, so inbreeding and loss of genetic diversity become a risk. Enforcement against poaching, illegal clearing and unauthorised access can be difficult and expensive, especially over large remote areas.

Zoos and sanctuaries breed threatened species to boost numbers, sometimes for later release. Zoos Victoria's Fighting Extinction program has bred species such as the orange-bellied parrot, helmeted honeyeater and Tasmanian devil (insurance populations free of facial tumour disease) for reintroduction.

Seeds, tissue, sperm or eggs are stored to preserve genetic material. The Victorian Conservation Seedbank at the Royal Botanic Gardens stores native seed for research and revegetation.