- Better Choice
NT, NSW, WA, SA, TAS
- Oyster farming has a very low overall impact on our oceans.
- Both native and invasive species of oyster are farmed in Australia.
- Pacific oysters were introduced in the 1940s and have formed natural populations in areas previously colonized by native oysters. Further spread is now managed through regulations on transport and farming practices.
- Recent viral outbreaks in wild and farmed oyster populations have led to stricter controls on farming, which appear effective in reducing the impact of the virus.
- Oyster larvae settle on longlines or racks in the ocean and grow in situ.
- Oysters filter food from the water and do not require feed.
- NSW (Sydney Rock, Pacific & Native Oysters; 3,767t in 2016-17)
- SA (Pacific & Native Oysters; 5,158t in 2016-17)
- TAS (Pacific & Native Oysters; 3,000t in 2016-17)
- WA & NT (Silver-lipped Pearl Oyster; production not reported)
A number of different species of oyster are farmed in Australia. Three of the species naturally occur in Australia – Sydney rock oysters, native oysters (also called Flat or Angasi oysters), and silver-lipped pearl oysters. The invasive Pacific oyster is also farmed here.
The silver-lipped pearl oyster is primarily farmed for pearl production, with the meat sold in low volumes as byproduct of pearl production.
Pacific oysters were first introduced into Australia in the 1940s and immediately began displacing naturally occurring oysters. Pacific oysters are now declared a noxious species in almost all NSW waters because of their ability take over areas settled by Sydney rock oysters and farming is only permitted in areas where there is little additional environmental risk. Over time, it is likely that Pacific and native oyster populations have reached equilibrium. Although Pacific oysters are still farmed, transport of oyster spat and farming practices are now more tightly controlled in order to prevent further outbreaks in areas where Pacific oysters have not colonized.
Juvenile oysters are either sourced from the wild and grown on racks and ropes in the ocean, or developed in hatcheries. Neither method has a significant impact on the marine environment.
A range of diseases have severely affected oyster farming and wild oyster populations in some areas recently. A virus outbreak in Tasmania and South Australia affected both farmed and wild populations, but it is unclear how the virus has moved between wild and farmed populations, or whether the virus began in farmed populations. The outbreak led to stricter biosecurity rules, which appear to have been effective.
Oysters longlines and racks provide an anchor to which oyster larvae attach and grow. These structures cause minimal damage to the surrounding marine environment. Oysters filter food from the water, and do not require any input of feed from farmers. Oyster farming has a very low impact on our oceans overall.