Introduced Species
Port River
Introduced marine pests are plants or animals that are not native to an area, but have been introduced through human activity. They come in all shapes and sizes, from microscopic algae to sea stars. Ships that travel into the Port River can carry marine animals and plants from other parts of the world in their ballast water or attached to their hulls.
Click here for information about introduced marine pests in SA
How it impacts the coastal environment
Most introduced marine pests do not survive or have little environmental impact once established. However, some ‘invaders’ are tough and achieve pest status by either
- eating other native animals or plants
- competing with local species for food and/or space
- altering the marine environment
- having no natural predators or conditions to control their spread or growth.
An example:
The recent discovery of the introduced seaweed Caulerpa taxifolia at West Lakes and in the Port River estuary is of great concern. It may have been carried from interstate on boating gear or dumped from a home saltwater aquarium. This weed is known as “the killer algae” as it grows in thick mats across native seagrass meadows, smothering their leaves and eventually displacing them. The algae also contain toxins, preventing small animals from using it as habitat and as a food source. If this weeds spreads into the Gulf St Vincent it will affect much of our native seagrass meadows and fish species that are ecologically and commercially very important to us.