Understanding Biotechnology

What is Biotechnology

Overview of Biotechnology

History of Biotechnology

Why do we do biotechnology?

Biotechnology for the environment

Biotechnology for food and agriculture

One application of biotechnology is biological control – attempting to eradicate introduced plant or animal pests (such as prickly pear and rabbits), or to reduce the harm they do to the environment. Being an island continent makes such an exercise conceivable, but what can we do to re-establish diversity? Which year should we take as the starting point for measuring diversity?

In Australia, our native plants and animals have adapted to life on an isolated continent over millions of years. However, particularly since European settlement, our native animals have had to compete with a range of introduced animals for food, habitat and shelter.

Some of our native species have also had to face new predators. Rapid changes in land usage, such as increased crop growing areas, have also affected our soils and waterways.

Feral Animals

Feral animals causing most public concern are: rabbits, foxes, cats, pigs, goats, donkeys, horses, camels, water buffalo, introduced fish, the northern Pacific seastar (Asterias amurensis), the Indian mynah and cane toads.

These species have few natural predators or fatal diseases in Australia and some have high reproductive rates. As a result, their populations can multiply rapidly if conditions are favourable. Drought is the main factor controlling their populations, as numbers drop quickly when food and water are limited.

Some feral animals prey on native animals and compete with them for food, shelter and habitat. Some feral animals may compete with livestock for food, or prey on our livestock. They can also cause damage to the land and waterways used by farmers and native animals.

Domestic rabbits were first introduced to Australia with the first fleet in 1788. However, they did not become established in the wild until Thomas Austin brought 24 wild rabbits from England in 1859, and released them for hunting on his property in southern Victoria. They bred so well that by 1866, only seven years later, 14,253 rabbits were recorded as being shot for sport on the property.

Methods to control feral pests

You can investigate the practicality, effectiveness, cost and effect on other species of each of these methods at a number of websites. These feral animal websites make it clear that animals must be treated humanely during control of feral pests.

Biological control

Natural predators & diseases

Ideally, using a specific predator means that we do not need to rely on chemical pesticides or other methods that may harm the ecosystem. However, care is needed, because introduced species are among the biggest causes of extinction of native plants and animals. Sometimes, the predator can do more harm than good.

In Australia, biological control has often been used successfully, including the introduction of a beetle to control prickly pear and a weevil to control water hyacinth. But one application of this form of biological control - the cane toad - went very wrong.

The cane toad was introduced into Queensland in 1935 to eat a pest beetle that was ruining sugar cane crops. However, the cane toad failed to control the beetle and instead thrived in the warm climate.

The cane toad has now spread widely through northern Australia, devastating populations of native species and changing the ecology of areas well beyond the borders of Queensland. It has even reached Kakadu National Park – a World Heritage Area in the Northern Territory, where it has the potential to do tremendous damage.

Before any new organism can be introduced, its biology and potential effects on Australian ecosystems must be extensively researched. This may take several years. Other precautions include the strict controls that the Australian Quarantine and Inspection Service (AQIS) applies to help prevent the unauthorised introduction of new organisms into Australia. These steps are designed to avoid a repeat of the cane toad episode.

However, we cannot always predict how new species will interact in a complex and open system such as the environment.

It is unlikely that biotechnology will provide a magic bullet solution for feral animal control. Usually, a biotechnology solution would have to be used in combination with other control methods mentioned above.