Growing Triploid Pacific’s in NSW needs careful consideration by farmers as there are several good reasons to do it, but growers intending to grow them are presented with dilemmas,
As mentioned previously it diversifies growers income base. It appears that at least 30% of the NSW oyster market is Pacific Oysters, being especially popular with Asian people as they are used to this type of oyster. Pacific’s also grow quickly enabling growers to get faster returns on their investment.
On the down side the introduction of these oysters could lead to overstocking of estuaries with less food being available for the existing Rock Oysters and also slowing growth of the Pacific’s, which could lower returns from all shellfish. Farmers considering growing Pacific’s thus need to be careful of their stocking densities.
Farming Pacific’s is different to Rock Oysters. They grow quickly and need to be handled more often to maintain the correct densities in growing containers and to attain the shape needed to be commercially marketable.
Diseases in oysters seem to be specific to types of oysters eg. Rock Oysters – Q.X. disease and winter mortality. Pacific oysters POMS (Pacific Oyster Mortality Syndrome – a herpes virus) and angasis- bonamia . These diseases already exist in other estuaries in NSW eg POMS wiped out the Hawksbury Triploid Pacific Industry and is predicted to spread. Feral Pacifc Oysters in NSW Rivers could aid the spread of POMS and therefore making it risky to spend a lot of capital introducing Triploid Pacific Oysters. Fisheries Research worldwide is moving toward breeding disease resistant Triploid Pacifc Oysters. This is at least 5 years away.
So before moving this way, growers have a lot to consider and in my opinion need to take a cautious approach.