Quarantine officers make sure no new diseases or pests are brought into Australia.
There are many diseases and pests from other countries that don't live in Australia. These could get into Australia when live animal or plant material is imported.
A quarantine system enables the safe importation of live animal and plant material. When the animals and plants arrive in Australia they are stored and looked after in a secure area for several weeks where pests and germs can't escape.
While they are being cared for, they are closely watched to see if they get sick. If they get sick experts (e.g. vets, horticulturalists, entomologists) must find the cause.
If there is a problem, the plants or animals can be destroyed so there is no risk to Australian animals or plants. Otherwise, after the required quarantine period the animals and plants can be collected by the importers.
Quarantine officers also check ships' ballast water. They make sure there are no marine pests from another country in the ballast water.