QX-resistant oysters live up to expectations

Latest research trials with QX-resistant oysters in the Hawkesbury River offer great hope to an industry devastated by the disease just two years ago.

In 2005, 90 percent of oysters grown in the Hawkesbury River were wiped out by QX disease.

NSW Department of Primary Industries (NSW DPI) research scientist, Dr John Nell, says QX-resistant oysters grown in the heavily QX-affected Kimmerikong harvest area in the Hawkesbury River have passed another milestone. 

“QX-resistant oysters bred by NSW DPI have been continuously maintained in this area since 2005 and have been subject to two heavy QX outbreaks. 

“In this site, 96 percent of normal oysters have died.

“This compares to deaths in just 20 percent of the QX-resistant line, and about half of these can be attributed not to QX but to flatworm and excessive heat”, Dr Nell said.

In late April 2007, an assessment was made of the marketability of QX resistant stock grown by ten producers at Kimmerikong.

Dr Nell said this found that 88 percent of the stock was in good marketable condition, which was excellent for that time of year.

NSW DPI efforts to support the oyster industry following the 2005 outbreak in the Hawkesbury included delivering QX-resistant oyster to local producers to enable them to get back into production.

The first oysters to reach market since the outbreak did so just before Easter, more than six months earlier than expected.

NSW DPI staff also worked with producers to adopt better standards in production systems and improve occupational health and safety standards.