Wild abalone off the coast of Cape Nelson have tested positive for a disease called Abalone Virus Ganglioneuritis.
Victoria's Chief Veterinary Officer said the disease affects the nervous system of abalone, resulting in curling of the foot and swelling of the mouth leading to weakness and death, with about 90 per cent of affected abalone dying.
There are no known risks to human health and abalone remain safe to eat.
"Thank you to the diver who noticed a cluster of dead abalone and reported it immediately. This is crucial to helping us act quickly and understand the extent disease spread," Dr Cooke said.
A Control Area has been declared to assist in limiting the spread of disease. The Control Area spans along the coastline from the middle of Bridgewater Bay in the west to past Narrawong Coastal Reserve in the east and is varied between two and 10km offshore. This includes areas of Portland.
In the Control Area, you cannot fish from shore or boat, use commercial fishing or abalone equipment, use hoop nets, bait traps, hauling nets and abalone levers for recreational fishing. All abalone, rock lobsters, sea urchins and other aquatic invertebrates cannot be collected, whether live or dead. Boats, vessels and fishing equipment cannot be anchored in the Control Area, however a vessel can move through the area provided it does not stop. A permit must be obtained to move any abalone out of the Control Area.
The Port of Portland breakwater is exempt from the Control Area for use of boat ramps and anchoring, and the Portland Anchorage area for commercial vessels greater than 35 meters in length.
Abalone disease was first detected on a farm in Victoria in December 2005. The last recorded instance was in the wild in January 2010 at Cape Otway.
"Since the first confirmed outbreak of the virus in Australia it was successfully eradicated from farms and had not been detected in the wild in Victoria for more than 10 years.
"It can spread through the water from infected abalone or abalone product (offal, shells or mucus), fishing equipment (including wetsuits, anchors, rock lobster pots and ropes) and via people who have come into contact with infected abalone."
Dr Cooke said only one wild cluster had been identified at this stage as positive, and there was no sign of disease on farms.
"We've been very fortunate that there hadn't been any detections in more than 10 years," Dr Cooke said.
"This is an important reminder to think about biosecurity when you're at the beach or out in the water – as humans can sometimes carry pests and diseases to other areas. Always wash down your boats, wetsuits and equipment.
