Fouling of mussel shells by can be problematic for the Mussel Aquaculture Industry, as fouled shells are perceived to be an inferior product. Mussel with more than 7% of the shell surface fouled is not considered Grade A quality, as the product is considered visually unattractive. The mussel industry in Port Phillip Bay maintains its competitive edge in Asian markets by trading in premium quality mussels only.

Fouling by the Serpulid tube worm represents a particular threat to industry viability, productivity and profitability as calcareous tubes >5 mm cannot be removed from the mussel shell degrading product value.

Reports indicated that heavy settlement of tube worm in Scottish mussel farms resulted in entire mussel stocks being discarded at an estimated cost to the Scottish industry of between £300,000 and £500,000 per annum. Tube worm biofouling costs millions of dollar of losses in many other shellfish aquaculture industries around the world.
In May and June this year, serpulid tube worms settled on mussel crops in great numbers in Port Phillip Bay. This infestation has occurred on hundreds of tonnes of SeaBounty cultured mussel and similar levels of infestation have been reported on several other shellfish farms within Port Phillip Bay. This infestation is heavy affecting 80% of the stock.

At present there is no treatment that can be applied to mussel at the early stages of infestation, that will kill the worm while maintaining a quality product (i.e 7% fouling).

An urgent R&D project is needed to complete this research and test both the efficacy and practicality of possible treatment on-farm.