From 24 to 29 March 2013, oysters harvested and sold near Dunalley contained a norovirus that caused an outbreak of gastroenteritis. Authorities removed the oysters from sale on 31 March after up to 60 people initially presented with gastroenteritis symptoms in Tasmania and investigations commenced.

The Public and Environmental Health Service of Tasmania advised that the source of the oyster contamination was a private sewage line nearby at Dunalley. Once the contamination source was identified, a temporary closure of other small oyster harvest zones further out to sea occurred as a precaution.

The volume of sewage leaking from the pipe was very low, and the leaking underground pipe was capped while the owner carried out repairs. Investigations confirmed the oyster lease in question was the only source of the oysters causing illness.

Health authorities estimated approximately 100 Tasmanians and up to 80 Victorians contracted gastroenteritis after eating the oysters at Easter, with some requiring hospitalisation.